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Prodigiosins (prodiginines) are a class of bacterial secondary metabolites with remarkable biological activities and color. In this study, optimized production, purification, and characterization of prodigiosin (PG) from easily accessible Serratia marcescens ATCC 27117 strain has been achieved to levels of 14 mg/L of culture within 24 h. Furthermore, environmentally friendly bromination of produced PG was used to afford both novel mono- and dibrominated derivatives of PG. PG and its Br derivatives showed anticancer potential with IC50 values range 0.62-17.00 mu g/mL for all tested cancer cell lines and induction of apoptosis but low selectivity against healthy cell lines. All compounds did not affect Caenorhabditis elegans at concentrations up to 50 mu g/mL. However, an improved toxicity profile of Br derivatives in comparison to parent PG was observed in vivo using zebrafish (Danio rerio) model system, when 10 mu g/mL applied at 6 h post fertilization caused death rate of 100%, 30% and 0% by PG, PG-Br, and PG-Br-2,Br- respectively, which is a significant finding for further structural optimizations of bacterial prodigiosins. The drug-likeness of PG and its Br derivatives was examined, and the novel Br derivatives obey the Lipinski's "rule of five", with an exemption of being more lipophilic than PG, which still makes them good targets for further structural optimization.

Cold-tolerant bacteria are known to contaminate and cause defects in refrigerated foods. Defects in food products can be observed as changes in appearance, texture, and/or flavor that detract from the product's intended look, feel, or taste. Two distinct organisms were cultured from blue pigmented soymilk and tofu that had been left opened and expired in a home refrigerator. The blue coloration was reproduced when isolates were cultured in fresh, sterile soymilk. These strains also produced a variety of colony color morphologies when cultured on different media types. We report two draft genome sequences of the potential causative agents of blue discoloration of soy foods, Pseudomonas carnis strains UCD_MED3 and UCD_MED7 as well as the 16S rRNA gene sequences of co-occurring strains isolated from the defective soy samples but that did not cause blue discoloration when cultured in fresh soymilk; Serratia liquefaciens strains UCD_MED2 and UCD_MED5.

Cold-tolerant bacteria are known to contaminate and cause defects in refrigerated foods. Defects in food products can be observed as changes in appearance, texture, and/or flavor that detract from the product's intended look, feel, or taste. Two distinct organisms were cultured from blue pigmented soymilk and tofu that had been left opened and expired in a home refrigerator. The blue coloration was reproduced when isolates were cultured in fresh, sterile soymilk. These strains also produced a variety of colony color morphologies when cultured on different media types. We report two draft genome sequences of the potential causative agents of blue discoloration of soy foods, Pseudomonas carnis strains UCD_MED3 and UCD_MED7 as well as the 16S rRNA gene sequences of co-occurring strains isolated from the defective soy samples but that did not cause blue discoloration when cultured in fresh soymilk; Serratia liquefaciens strains UCD_MED2 and UCD_MED5.

Serratia sp. cause food losses and waste due to spoilage; it is noteworthy that they represent a dominant population in seafood. The main spoilage associated species comprise S. liquefaciens, S. grimesii, S. proteamaculans and S. quinivorans, also known as S. liquefaciens-like strains. These species are difficult to discriminate since classical 16S rRNA gene-based sequences do not possess sufficient resolution. In this study, a phylogeny based on the short-length luxS gene was able to speciate 47 Serratia isolates from seafood, with S. proteamaculans being the main species from fresh salmon and tuna, cold-smoked salmon, and cooked shrimp while S. liquefaciens was only found in cold-smoked salmon. The genome of the first S. proteamaculans strain isolated from the seafood matrix (CD3406 strain) was sequenced. Pangenome analyses of S. proteamaculans and S. liquefaciens indicated high adaptation potential. Biosynthetic pathways involved in antimicrobial compounds production and in the main seafood spoilage compounds were also identified. The genetic equipment highlighted in this study contributed to gain further insights into the predominance of Serratia in seafood products and their capacity to spoil.

The cases of human infections caused by Serratia fonticola are relatively rare. The few cases that have been reported primarily describe skin and soft tissue, urinary, and biliary tract infections. We describe a case of a 59-year-old man with infected bilateral lower extremity wounds who developed endocarditis due to S fonticola confirmed with transesophageal echocardiogram. The patient was treated with 6 weeks of antibiotic therapy and had an uneventful recovery. After a thorough review of the literature using PubMed and Google Scholar, we concluded that this is the first reported case of endocarditis caused by S fonticola.

Serratia sp. cause food losses and waste due to spoilage; it is noteworthy that they represent a dominant population in seafood. The main spoilage associated species comprise S. liquefaciens, S. grimesii, S. proteamaculans and S. quinivorans, also known as S. liquefaciens-like strains. These species are difficult to discriminate since classical 16S rRNA gene-based sequences do not possess sufficient resolution. In this study, a phylogeny based on the short-length luxS gene was able to speciate 47 Serratia isolates from seafood, with S. proteamaculans being the main species from fresh salmon and tuna, cold-smoked salmon, and cooked shrimp while S. liquefaciens was only found in cold-smoked salmon. The genome of the first S. proteamaculans strain isolated from the seafood matrix (CD3406 strain) was sequenced. Pangenome analyses of S. proteamaculans and S. liquefaciens indicated high adaptation potential. Biosynthetic pathways involved in antimicrobial compounds production and in the main seafood spoilage compounds were also identified. The genetic equipment highlighted in this study contributed to gain further insights into the predominance of Serratia in seafood products and their capacity to spoil.

Childhood alopecia is a rare disease, with an estimated 1% of pediatric dermatological consultations. Skin, eye and tissue infections by Serratia marcescens are rarely reported. We report a case of a female patient, two years and three months old, with painful lesions in the biparietal region of the scalp for two months, with an exulcerated, crusted aspect, associated with serosanguinolent, purulent secretion and with alopecia. She was initially treated with antifungal and empirical, systemic and topical antibiotic therapy, according to the Kerion Celsi hypothesis, without improvement. The isolated growth of the bacterium Serratia marcescens was observed, thus establishing a diagnosis of alopecia by bacterial etiology, and treatment with sulfamethoxazole/trimetropin (30 + 6 mg/Kg/d) was started for ten days, with the resolution of the infectious condition and onset of area repilation of alopecia, leaving only small scarred areas as a sequel., Alopecia infantil é uma doença rara, com uma ocorrência estimada em 1% das consultas dermatológicas pediátricas. Infecções cutâneas, oculares e do mesmo tecido por Serratia marcescens raramente são relatadas. Relata-se um caso de uma paciente do sexo feminino, 2 anos e 3 meses de idade, com quadro de lesões dolorosas em região biparietal do couro cabeludo há dois meses, de aspecto exulcerado, crostoso, associado a secreção serossanguinolenta, purulenta e com alopecia. Inicialmente tratada com antifúngico e antibioticoterapia empírica, sistêmica e tópica, pela hipótese de Kerion Celsi, sem melhora. Foi observado o crescimento isolado da bactéria Serratia marcescens, estabelecendo assim diagnóstico de alopecia por etiologia bacteriana, sendo iniciado tratamento com sulfametoxazol/trimetropin (30 + 6 mg/kg/dia) por 10 dias, com resolução do quadro infeccioso e início da repilação em área de alopecia, restando apenas pequenas áreas cicatriciais como sequela.

Childhood alopecia is a rare disease, with an estimated 1% of pediatric dermatological consultations. Skin, eye and tissue infections by Serratia marcescens are rarely reported. We report a case of a female patient, two years and three months old, with painful lesions in the biparietal region of the scalp for two months, with an exulcerated, crusted aspect, associated with serosanguinolent, purulent secretion and with alopecia. She was initially treated with antifungal and empirical, systemic and topical antibiotic therapy, according to the Kerion Celsi hypothesis, without improvement. The isolated growth of the bacterium Serratia marcescens was observed, thus establishing a diagnosis of alopecia by bacterial etiology, and treatment with sulfamethoxazole/trimetropin (30 + 6 mg/Kg/d) was started for ten days, with the resolution of the infectious condition and onset of area repilation of alopecia, leaving only small scarred areas as a sequel., Alopecia infantil é uma doença rara, com uma ocorrência estimada em 1% das consultas dermatológicas pediátricas. Infecções cutâneas, oculares e do mesmo tecido por Serratia marcescens raramente são relatadas. Relata-se um caso de uma paciente do sexo feminino, 2 anos e 3 meses de idade, com quadro de lesões dolorosas em região biparietal do couro cabeludo há dois meses, de aspecto exulcerado, crostoso, associado a secreção serossanguinolenta, purulenta e com alopecia. Inicialmente tratada com antifúngico e antibioticoterapia empírica, sistêmica e tópica, pela hipótese de Kerion Celsi, sem melhora. Foi observado o crescimento isolado da bactéria Serratia marcescens, estabelecendo assim diagnóstico de alopecia por etiologia bacteriana, sendo iniciado tratamento com sulfametoxazol/trimetropin (30 + 6 mg/kg/dia) por 10 dias, com resolução do quadro infeccioso e início da repilação em área de alopecia, restando apenas pequenas áreas cicatriciais como sequela.

Childhood alopecia is a rare disease, with an estimated 1% of pediatric dermatological consultations. Skin, eye and tissue infections by Serratia marcescens are rarely reported. We report a case of a female patient, two years and three months old, with painful lesions in the biparietal region of the scalp for two months, with an exulcerated, crusted aspect, associated with serosanguinolent, purulent secretion and with alopecia. She was initially treated with antifungal and empirical, systemic and topical antibiotic therapy, according to the Kerion Celsi hypothesis, without improvement. The isolated growth of the bacterium Serratia marcescens was observed, thus establishing a diagnosis of alopecia by bacterial etiology, and treatment with sulfamethoxazole/trimetropin (30 + 6 mg/Kg/d) was started for ten days, with the resolution of the infectious condition and onset of area repilation of alopecia, leaving only small scarred areas as a sequel., Alopecia infantil é uma doença rara, com uma ocorrência estimada em 1% das consultas dermatológicas pediátricas. Infecções cutâneas, oculares e do mesmo tecido por Serratia marcescens raramente são relatadas. Relata-se um caso de uma paciente do sexo feminino, 2 anos e 3 meses de idade, com quadro de lesões dolorosas em região biparietal do couro cabeludo há dois meses, de aspecto exulcerado, crostoso, associado a secreção serossanguinolenta, purulenta e com alopecia. Inicialmente tratada com antifúngico e antibioticoterapia empírica, sistêmica e tópica, pela hipótese de Kerion Celsi, sem melhora. Foi observado o crescimento isolado da bactéria Serratia marcescens, estabelecendo assim diagnóstico de alopecia por etiologia bacteriana, sendo iniciado tratamento com sulfametoxazol/trimetropin (30 + 6 mg/kg/dia) por 10 dias, com resolução do quadro infeccioso e início da repilação em área de alopecia, restando apenas pequenas áreas cicatriciais como sequela.

Background: The optimal treatment duration for patients with bloodstream infection is understudied. The Bacteremia Antibiotic Length Actually Needed for Clinical Effectiveness (BALANCE) pilot randomized clinical trial (RCT) determined that it was feasible to enroll and randomize intensive care unit (ICU) patients with bloodstream infection to 7 versus 14 days of treatment, and served as the vanguard for the ongoing BALANCE main RCT. We performed this BALANCE-Ward pilot RCT to examine the feasibility and impact of potentially extending the BALANCE main RCT to include patients hospitalized on non-ICU wards. Method(s): We conducted an open pilot RCT among a subset of six sites participating in the ongoing BALANCE RCT, randomizing patients with positive non-Staphylococcus aureus blood cultures on non-ICU wards to 7 versus 14 days of antibiotic treatment. The co-primary feasibility outcomes were recruitment rate and adherence to treatment duration protocol. We compared feasibility outcomes, patient/pathogen characteristics, and overall outcomes among those enrolled in this BALANCE-Ward and prior BALANCE-ICU pilot RCTs. We estimated the sample size and non-inferiority margin impacts of expanding the BALANCE main RCT to include non-ICU patients. Result(s): A total of 134 patients were recruited over 47 site-months (mean 2.9 patients/site-month, median 1.0, range 0.1-4.4 patients/site-month). The overall recruitment rate exceeded the BALANCE-ICU pilot RCT (mean 1.10 patients/site-month, p < 0.0001). Overall protocol adherence also exceeded the adherence in the BALANCE-ICU pilot RCT (125/134, 93% vs 89/115, 77%, p = 0.0003). BALANCE-Ward patients were older, with lower Sequential Organ Failure Assessment scores, and higher proportions of infections caused by Escherichia coli and genito-urinary sources of bloodstream infection. The BALANCE-Ward pilot RCT patients had an overall 90-day mortality rate of 17/133 (12.8%), which was comparable to the 90-day mortality rate in the I

Background: The optimal treatment duration for patients with bloodstream infection is understudied. The Bacteremia Antibiotic Length Actually Needed for Clinical Effectiveness (BALANCE) pilot randomized clinical trial (RCT) determined that it was feasible to enroll and randomize intensive care unit (ICU) patients with bloodstream infection to 7 versus 14 days of treatment, and served as the vanguard for the ongoing BALANCE main RCT. We performed this BALANCE-Ward pilot RCT to examine the feasibility and impact of potentially extending the BALANCE main RCT to include patients hospitalized on non-ICU wards. Method(s): We conducted an open pilot RCT among a subset of six sites participating in the ongoing BALANCE RCT, randomizing patients with positive non-Staphylococcus aureus blood cultures on non-ICU wards to 7 versus 14 days of antibiotic treatment. The co-primary feasibility outcomes were recruitment rate and adherence to treatment duration protocol. We compared feasibility outcomes, patient/pathogen characteristics, and overall outcomes among those enrolled in this BALANCE-Ward and prior BALANCE-ICU pilot RCTs. We estimated the sample size and non-inferiority margin impacts of expanding the BALANCE main RCT to include non-ICU patients. Result(s): A total of 134 patients were recruited over 47 site-months (mean 2.9 patients/site-month, median 1.0, range 0.1-4.4 patients/site-month). The overall recruitment rate exceeded the BALANCE-ICU pilot RCT (mean 1.10 patients/site-month, p < 0.0001). Overall protocol adherence also exceeded the adherence in the BALANCE-ICU pilot RCT (125/134, 93% vs 89/115, 77%, p = 0.0003). BALANCE-Ward patients were older, with lower Sequential Organ Failure Assessment scores, and higher proportions of infections caused by Escherichia coli and genito-urinary sources of bloodstream infection. The BALANCE-Ward pilot RCT patients had an overall 90-day mortality rate of 17/133 (12.8%), which was comparable to the 90-day mortality rate in the I

Childhood alopecia is a rare disease, with an estimated 1% of pediatric dermatological consultations. Skin, eye and tissue infections by Serratia marcescens are rarely reported. We report a case of a female patient, two years and three months old, with painful lesions in the biparietal region of the scalp for two months, with an exulcerated, crusted aspect, associated with serosanguinolent, purulent secretion and with alopecia. She was initially treated with antifungal and empirical, systemic and topical antibiotic therapy, according to the Kerion Celsi hypothesis, without improvement. The isolated growth of the bacterium Serratia marcescens was observed, thus establishing a diagnosis of alopecia by bacterial etiology, and treatment with sulfamethoxazole/trimetropin (30 + 6 mg/Kg/d) was started for ten days, with the resolution of the infectious condition and onset of area repilation of alopecia, leaving only small scarred areas as a sequel., Alopecia infantil é uma doença rara, com uma ocorrência estimada em 1% das consultas dermatológicas pediátricas. Infecções cutâneas, oculares e do mesmo tecido por Serratia marcescens raramente são relatadas. Relata-se um caso de uma paciente do sexo feminino, 2 anos e 3 meses de idade, com quadro de lesões dolorosas em região biparietal do couro cabeludo há dois meses, de aspecto exulcerado, crostoso, associado a secreção serossanguinolenta, purulenta e com alopecia. Inicialmente tratada com antifúngico e antibioticoterapia empírica, sistêmica e tópica, pela hipótese de Kerion Celsi, sem melhora. Foi observado o crescimento isolado da bactéria Serratia marcescens, estabelecendo assim diagnóstico de alopecia por etiologia bacteriana, sendo iniciado tratamento com sulfametoxazol/trimetropin (30 + 6 mg/kg/dia) por 10 dias, com resolução do quadro infeccioso e início da repilação em área de alopecia, restando apenas pequenas áreas cicatriciais como sequela.

Childhood alopecia is a rare disease, with an estimated 1% of pediatric dermatological consultations. Skin, eye and tissue infections by Serratia marcescens are rarely reported. We report a case of a female patient, two years and three months old, with painful lesions in the biparietal region of the scalp for two months, with an exulcerated, crusted aspect, associated with serosanguinolent, purulent secretion and with alopecia. She was initially treated with antifungal and empirical, systemic and topical antibiotic therapy, according to the Kerion Celsi hypothesis, without improvement. The isolated growth of the bacterium Serratia marcescens was observed, thus establishing a diagnosis of alopecia by bacterial etiology, and treatment with sulfamethoxazole/trimetropin (30 + 6 mg/Kg/d) was started for ten days, with the resolution of the infectious condition and onset of area repilation of alopecia, leaving only small scarred areas as a sequel., Alopecia infantil é uma doença rara, com uma ocorrência estimada em 1% das consultas dermatológicas pediátricas. Infecções cutâneas, oculares e do mesmo tecido por Serratia marcescens raramente são relatadas. Relata-se um caso de uma paciente do sexo feminino, 2 anos e 3 meses de idade, com quadro de lesões dolorosas em região biparietal do couro cabeludo há dois meses, de aspecto exulcerado, crostoso, associado a secreção serossanguinolenta, purulenta e com alopecia. Inicialmente tratada com antifúngico e antibioticoterapia empírica, sistêmica e tópica, pela hipótese de Kerion Celsi, sem melhora. Foi observado o crescimento isolado da bactéria Serratia marcescens, estabelecendo assim diagnóstico de alopecia por etiologia bacteriana, sendo iniciado tratamento com sulfametoxazol/trimetropin (30 + 6 mg/kg/dia) por 10 dias, com resolução do quadro infeccioso e início da repilação em área de alopecia, restando apenas pequenas áreas cicatriciais como sequela.

Childhood alopecia is a rare disease, with an estimated 1% of pediatric dermatological consultations. Skin, eye and tissue infections by Serratia marcescens are rarely reported. We report a case of a female patient, two years and three months old, with painful lesions in the biparietal region of the scalp for two months, with an exulcerated, crusted aspect, associated with serosanguinolent, purulent secretion and with alopecia. She was initially treated with antifungal and empirical, systemic and topical antibiotic therapy, according to the Kerion Celsi hypothesis, without improvement. The isolated growth of the bacterium Serratia marcescens was observed, thus establishing a diagnosis of alopecia by bacterial etiology, and treatment with sulfamethoxazole/trimetropin (30 + 6 mg/Kg/d) was started for ten days, with the resolution of the infectious condition and onset of area repilation of alopecia, leaving only small scarred areas as a sequel., Alopecia infantil é uma doença rara, com uma ocorrência estimada em 1% das consultas dermatológicas pediátricas. Infecções cutâneas, oculares e do mesmo tecido por Serratia marcescens raramente são relatadas. Relata-se um caso de uma paciente do sexo feminino, 2 anos e 3 meses de idade, com quadro de lesões dolorosas em região biparietal do couro cabeludo há dois meses, de aspecto exulcerado, crostoso, associado a secreção serossanguinolenta, purulenta e com alopecia. Inicialmente tratada com antifúngico e antibioticoterapia empírica, sistêmica e tópica, pela hipótese de Kerion Celsi, sem melhora. Foi observado o crescimento isolado da bactéria Serratia marcescens, estabelecendo assim diagnóstico de alopecia por etiologia bacteriana, sendo iniciado tratamento com sulfametoxazol/trimetropin (30 + 6 mg/kg/dia) por 10 dias, com resolução do quadro infeccioso e início da repilação em área de alopecia, restando apenas pequenas áreas cicatriciais como sequela.

BackgroundSerratia plymuthica WS3236 was selected for whole genome sequencing based on preliminary genetic and chemical screening indicating the presence of multiple natural product pathways. This led to the identification of a putative sodorifen biosynthetic gene cluster (BGC). The natural product sodorifen is a volatile organic compound (VOC) with an unusual polymethylated hydrocarbon bicyclic structure (C16H26) produced by selected strains of S. plymuthica. The BGC encoding sodorifen consists of four genes, two of which (sodA, sodB) are homologs of genes encoding enzymes of the non-mevalonate pathway and are thought to enhance the amounts of available farnesyl pyrophosphate (FPP), the precursor of sodorifen. Proceeding from FPP, only two enzymes are necessary to produce sodorifen: an S-adenosyl methionine dependent methyltransferase (SodC) with additional cyclisation activity and a terpene-cyclase (SodD). Previous analysis of S. plymuthica found sodorifen production titers are generally low and vary significantly among different producer strains. This precludes studies on the still elusive biological function of this structurally and biosynthetically fascinating bacterial terpene.ResultsSequencing and mining of the S. plymuthica WS3236 genome revealed the presence of 38 BGCs according to antiSMASH analysis, including a putative sodorifen BGC. Further genome mining for sodorifen and sodorifen-like BGCs throughout bacteria was performed using SodC and SodD as queries and identified a total of 28 sod-like gene clusters. Using direct pathway cloning (DiPaC) we intercepted the 4.6 kb candidate sodorifen BGC from S. plymuthica WS3236 (sodA-D) and transformed it into Escherichia coli BL21. Heterologous expression under the control of the tetracycline inducible PtetO promoter firmly linked this BGC to sodorifen production. By utilizing this newly established expression system, we increased the production yields by approximately 26-fold when compared to the native pr

Aims: The current study was aimed to evaluate the beneficial effects and bioremediation potential of a Cd-tolerant bacterial strain, Serratia sp. CP-13, on the physiological and biochemical functions of Linum usitatissimum L., under Cd stress. Methods and Results: The bacterial strain was isolated from the wastewater collection point of Chakera, Faisalabad, Pakistan, as this place contains industrial wastewater of the Faisalabad region. The Serratia sp. CP-13, identified through 16S rRNA gene sequence analysis, exhibited a significant phyto-beneficial potential in terms of in vitro inorganic phosphate solubilization, indole-3-acetic acid production and 1-aminocyclopropane-1-carboxylic acid deaminase activity. Effects of Serratia sp. CP-13 inoculation on L. usitatissimum were evaluated by growing the plants in CdCl2 (0, 5 or 10 mg kg(-1) dry soil)-spiked soil. Without inoculation of Serratia sp. CP-13, Cd stress significantly reduced the plant biomass as well as the quantity of proteins and photosynthetic pigments due to enhanced H2O2, malondialdehyde (MDA) contents and impaired nutrient homeostasis. Subsequently, Serratia sp. CP-13 increased the plant fresh and dry biomass, plant antioxidation capacity, whereas it decreased the lipid peroxidation under Cd stress. In parallel, Serratia sp. inoculation assisted the Cd-stressed plants to maintain an optimum level of nutrients (K, Ca, P, Mg, Fe and Mn). Conclusions: The isolated bacterial strain (Serratia sp. CP-13) when applied to Cd-stressed L. usitatissimum inhibited the Cd uptake, reduced Cd-induced lipid peroxidation, maintained the optimum level of nutrients and thereby, enhanced L. usitatissimum growth. The analysis of bio-concentration and translocation factor revealed that L. usitatissimum with Serratia sp. CP-13 inoculation sequestered Cd in plant rhizospheric zone. Significance and Impact of the Study: Serratia sp. CP-13 inoculation is a potential candidate for the development of low Cd-accumulating linseed a

Production of cucurbits has a long tradition worldwide. Cucumber, watermelon and melon production is very important for many producers in some parts of Serbia. These crops are especially susceptible to phytopathogenic bacteria which can cause substantial losses in years with favorable weather conditions. In this paper major bacterial diseases of cucurbits are described, such as bacterial fruit blotch caused by Acidovorax citrulli, angular leaf spot caused by Pseudomonas syringae pv. lachrymans, bacterial spot caused by Xanthomonas campestris, bacterial wilt caused by Erwinia tracheiphila, cucurbit yellow wine disease caused by Serratia marcescens, bacterial leaf spot, caused by Pseudomonas syringae pv. syringae, inducing bacterial soft rot caused by Pectobacterium species., Biljke familije Cucurbitaceae imaju dugu tradiciju proizvodnje širom sveta. U pojedinim krajevima Srbije, naročito severnim, proizvodnja krastavca, lubenice i dinje predstavlja primarno zanimanje mnogih poljoprivrednih gazdinstava. Pojava bakterioza u godinama sa uslovima koji pogoduju nastanku infekcije, može značajno ugroziti proizvodnju ovih biljaka. U ovom radu predstavljena su najznačajnija bakteriozna oboljenja biljaka familije Cucurbitaceae, među kojima su: bakteriozna mrljavost plodova lubenice, čiji je prouzrokovač Acidovorax citrulli, uglasta pegavost lišća krastavca, prouzrokovana bakterijom Pseudomonas syringae pv. lachrymans; bakteriozna uvelost krastavca prouzrokovana vrstom Erwinia tracheiphila; bakteriozna pegavost koju prouzrokuje Xanthomonas cucurbitae; potom žutilo vreža, čiji je prouzrokovač Serratia marcescens; zatim bakteriozna lisna pegavost prouzrokovana Pseudomonas syringae pv. syringae; kao i bakteriozna vlažna trulež prouzrokovana vrstama roda Pectobacterium.

BackgroundSerratia plymuthica WS3236 was selected for whole genome sequencing based on preliminary genetic and chemical screening indicating the presence of multiple natural product pathways. This led to the identification of a putative sodorifen biosynthetic gene cluster (BGC). The natural product sodorifen is a volatile organic compound (VOC) with an unusual polymethylated hydrocarbon bicyclic structure (C16H26) produced by selected strains of S. plymuthica. The BGC encoding sodorifen consists of four genes, two of which (sodA, sodB) are homologs of genes encoding enzymes of the non-mevalonate pathway and are thought to enhance the amounts of available farnesyl pyrophosphate (FPP), the precursor of sodorifen. Proceeding from FPP, only two enzymes are necessary to produce sodorifen: an S-adenosyl methionine dependent methyltransferase (SodC) with additional cyclisation activity and a terpene-cyclase (SodD). Previous analysis of S. plymuthica found sodorifen production titers are generally low and vary significantly among different producer strains. This precludes studies on the still elusive biological function of this structurally and biosynthetically fascinating bacterial terpene.ResultsSequencing and mining of the S. plymuthica WS3236 genome revealed the presence of 38 BGCs according to antiSMASH analysis, including a putative sodorifen BGC. Further genome mining for sodorifen and sodorifen-like BGCs throughout bacteria was performed using SodC and SodD as queries and identified a total of 28 sod-like gene clusters. Using direct pathway cloning (DiPaC) we intercepted the 4.6 kb candidate sodorifen BGC from S. plymuthica WS3236 (sodA-D) and transformed it into Escherichia coli BL21. Heterologous expression under the control of the tetracycline inducible PtetO promoter firmly linked this BGC to sodorifen production. By utilizing this newly established expression system, we increased the production yields by approximately 26-fold when compared to the native pr

Serlyticin-A is a secondary metabolite first isolated from a culture of Serratia ureilytica grown using squid pen as the sole carbon/nitrogen source. A previous study by Kuo et al. demonstrated that it has antioxidative and antiproliferative properties. However, the proposed chemical structure of serlyticin-A is likely incorrect based on the thermodynamic instability of its three contiguous heteroatom-heteroatom bonds. Here, we use quantum chemical calculations to predict 1H and 13C chemical shifts for serlyticin-A and demonstrate a discrepancy between the calculated and experimental chemical shifts. We then propose several reasonable alternative structures for serlyticin-A. Considering the known antioxidant and antiproliferative activity of hydroxamic acids as well as their stability and prevalence in natural products of bacterial origin, we believe that serlyticin-A is most likely 3-indolylacetohydroxamic acid (4). We provide our rationale for this assignment as well as experimental data for pure 3-indolylacetohydroxamic acid obtained via de novo synthesis. This study highlights the power of computational NMR shift prediction to revise chemical structures for natural products like serlyticin-A.

Production of cucurbits has a long tradition worldwide. Cucumber, watermelon and melon production is very important for many producers in some parts of Serbia. These crops are especially susceptible to phytopathogenic bacteria which can cause substantial losses in years with favorable weather conditions. In this paper major bacterial diseases of cucurbits are described, such as bacterial fruit blotch caused by Acidovorax citrulli, angular leaf spot caused by Pseudomonas syringae pv. lachrymans, bacterial spot caused by Xanthomonas campestris, bacterial wilt caused by Erwinia tracheiphila, cucurbit yellow wine disease caused by Serratia marcescens, bacterial leaf spot, caused by Pseudomonas syringae pv. syringae, inducing bacterial soft rot caused by Pectobacterium species., Biljke familije Cucurbitaceae imaju dugu tradiciju proizvodnje širom sveta. U pojedinim krajevima Srbije, naročito severnim, proizvodnja krastavca, lubenice i dinje predstavlja primarno zanimanje mnogih poljoprivrednih gazdinstava. Pojava bakterioza u godinama sa uslovima koji pogoduju nastanku infekcije, može značajno ugroziti proizvodnju ovih biljaka. U ovom radu predstavljena su najznačajnija bakteriozna oboljenja biljaka familije Cucurbitaceae, među kojima su: bakteriozna mrljavost plodova lubenice, čiji je prouzrokovač Acidovorax citrulli, uglasta pegavost lišća krastavca, prouzrokovana bakterijom Pseudomonas syringae pv. lachrymans; bakteriozna uvelost krastavca prouzrokovana vrstom Erwinia tracheiphila; bakteriozna pegavost koju prouzrokuje Xanthomonas cucurbitae; potom žutilo vreža, čiji je prouzrokovač Serratia marcescens; zatim bakteriozna lisna pegavost prouzrokovana Pseudomonas syringae pv. syringae; kao i bakteriozna vlažna trulež prouzrokovana vrstama roda Pectobacterium.

Objective To define the susceptibilities of the common causative pathogens of neonatal sepsis in the UK. Design Retrospective analysis of the prospectively collected neonIN infection surveillance network data between 2005 and 2014. Setting 30 neonatal units in the UK. Patients Newborns admitted to participating neonatal units who return a positive blood, cerebrospinal fluid or urine culture and are treated with at least 5 days of appropriate antibiotics. Results 1568 isolates with recorded antimicrobial data were collected including 328 early-onset sepsis (EOS) isolates and 1240 late-onset sepsis (LOS) isolates. The majority of EOS pathogens (>92%) were susceptible to the four empirical commonly used antimicrobial combinations (eg, 93% for benzylpenicillin/gentamicin), while LOS pathogens demonstrated higher levels of resistance (eg, 89% for flucloxacillin/gentamicin). Among infants<1500 g and <32 weeks gestation, an amoxicillin/gentamicin combination demonstrated a trend towards improved coverage of EOS isolates than benzylpenicillin/gentamicin (93% vs 86%, p=0.211). Conclusions This analysis provides insights into the patterns of antimicrobial resistance among UK neonatal pathogens. These data will inform areas of future research and can be used to update national evidence-based guidelines on antimicrobial usage.Copyright © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved.

Objective To define the susceptibilities of the common causative pathogens of neonatal sepsis in the UK. Design Retrospective analysis of the prospectively collected neonIN infection surveillance network data between 2005 and 2014. Setting 30 neonatal units in the UK. Patients Newborns admitted to participating neonatal units who return a positive blood, cerebrospinal fluid or urine culture and are treated with at least 5 days of appropriate antibiotics. Results 1568 isolates with recorded antimicrobial data were collected including 328 early-onset sepsis (EOS) isolates and 1240 late-onset sepsis (LOS) isolates. The majority of EOS pathogens (>92%) were susceptible to the four empirical commonly used antimicrobial combinations (eg, 93% for benzylpenicillin/gentamicin), while LOS pathogens demonstrated higher levels of resistance (eg, 89% for flucloxacillin/gentamicin). Among infants<1500 g and <32 weeks gestation, an amoxicillin/gentamicin combination demonstrated a trend towards improved coverage of EOS isolates than benzylpenicillin/gentamicin (93% vs 86%, p=0.211). Conclusions This analysis provides insights into the patterns of antimicrobial resistance among UK neonatal pathogens. These data will inform areas of future research and can be used to update national evidence-based guidelines on antimicrobial usage.Copyright © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved.

We report the isolation and identification of seven bacterial strains and one fungal strain from dead and diseased Scapteriscus borellii mole crickets collected from a golf course in southern California. Using 16S and 18S rRNA gene sequence analysis we identified the microbes as Serratia marcescens (red), S. marcescens (white), S. marcescens (purple), Achromobacter xylosoxidans, Chryseobacterium sp., Ochrobactrum anthropi, Tsukamurella tryosinosolvens, and Beauveria bassiana. We performed a dose response curve for each of these cricket-associated microbial strains (except T. tryosinosolvens) and two other strains of S. marcescens (DB1140 and ATCC 13880). We found that all of these microbes except O. anthropi were highly pathogenic to D. melanogaster compared to the other strains of S. marcescens. Injecting the mole cricket associated strains of Serratia into flies killed all infected flies in ≤24h. For all other strains, the median time to death of injected flies varied in a dose-dependent manner. In vivo growth assessments of these microbes suggested that the host immune system was quickly overcome. We used disease tolerance curves to better understand the host-microbe interactions. Further studies are necessary to understand in mechanistic detail the virulence mechanisms of these mole cricket associated microbes and how this association may have influenced the evolution of mole cricket immunity.

The Lord Howe Island stick insect (Dryococelus australis) is critically endangered in the wild. Once driven to near-extinction, the species now exists within just a few captive breeding programs that have been established to conserve the species, to increase population numbers through breeding, and to support the eventual reintroduction of the species into the wild. In the current study, the bacteria Serratia marcescens was investigated as a possible cause of mortality in a captive breeding colony of D. australis housed at Melbourne Zoo. S. marcescens was isolated from both dead insects and from the environment. The prevalence of the bacteria in dead insects was estimated, and the gross pathological and histopathological changes in infected insects were characterised. Strain types of S. marcescens were characterised using pulsed-field gel electrophoresis, and the strain type A1 was implicated as the most likely outbreak strain associated with insect deaths. Epidemiological risk factors for mortality were also investigated, and a novel PCR test was developed to facilitate rapid detection and identification of S. marcescens. The overall findings of this research suggest that S. marcescens is a potential opportunistic pathogen of D. australis, and is associated with haemocoelomitis and death. However, high virulence was not demonstrated in infected insects under experimental conditions. Recommendations for the future management of D. australis and the future reintroduction of the species to the wild are discussed in light of the findings from this research.

We report the isolation and identification of seven bacterial strains and one fungal strain from dead and diseased Scapteriscus borellii mole crickets collected from a golf course in southern California. Using 16S and 18S rRNA gene sequence analysis we identified the microbes as Serratia marcescens (red), S. marcescens (white), S. marcescens (purple), Achromobacter xylosoxidans, Chryseobacterium sp., Ochrobactrum anthropi, Tsukamurella tryosinosolvens, and Beauveria bassiana. We performed a dose response curve for each of these cricket-associated microbial strains (except T. tryosinosolvens) and two other strains of S. marcescens (DB1140 and ATCC 13880). We found that all of these microbes except O. anthropi were highly pathogenic to D. melanogaster compared to the other strains of S. marcescens. Injecting the mole cricket associated strains of Serratia into flies killed all infected flies in ≤24h. For all other strains, the median time to death of injected flies varied in a dose-dependent manner. In vivo growth assessments of these microbes suggested that the host immune system was quickly overcome. We used disease tolerance curves to better understand the host-microbe interactions. Further studies are necessary to understand in mechanistic detail the virulence mechanisms of these mole cricket associated microbes and how this association may have influenced the evolution of mole cricket immunity.

The Anopheles midgut hosts diverse bacterial communities and represents a complex ecosystem. Several evidences indicate that mosquito midgut microbiota interferes with malaria parasite transmission. However, the bacterial composition of salivary glands and ovaries, two other biologically important tissues, has not been described so far. In this study, we investigated the dynamics of the bacterial communities in the mosquito tissues from emerging mosquitoes until 8 days after a blood meal containing Plasmodium falciparum gametocytes and described the temporal colonization of the mosquito epithelia. Bacterial communities were identified in the midgut, ovaries, and salivary glands of individual mosquitoes using pyrosequencing of the 16S rRNA gene. We found that the mosquito epithelia share a core microbiota, but some bacteria taxa were more associated with one or another tissue at a particular time point. The bacterial composition in the tissues of emerging mosquitoes varied according to the breeding site, indicating that some bacteria are acquired from the environment. Our results revealed temporal variations in the bacterial community structure, possibly as a result of the mosquito physiological changes. The abundance of Serratia significantly correlated with P. falciparum infection both in the midgut and salivary glands of malaria challenged mosquitoes, which suggests that interactions occur between microbes and parasites. These bacteria may represent promising targets for vector control strategies. Overall, this study points out the importance of characterizing bacterial communities in malaria mosquito vectors.

The Health Services associated infections are a major cause of morbidity and mortality in the patients worldwide. They are present as consequences of the low quality of care and insufficient supervision and staff training. This paper aims to assess the presence of bacterial load in jar lids of antiseptic solutions and tweezers transfer present in carts cure emergency service Clinical Hospital Viedma 2015, since this material is in direct contact with patients and health personnel. The study is descriptive and transversal. Sterile swabs and culture broth (brain heart infu­sion) was used for sample collection, the sample was obtained from 18 jar lids antiseptic and 5 forceps transfer solutions, we proceeded to incubation in an oven, then he proceeded to seeded on blood agar and agar Mac- Conkey, observing colony growth Gram stain by which the presence of negative cocci, Gram positive bacilli and gram negative bacilli found was performed latter underwent biochemical tests for classification, which was found to Klebsiella pneumoniae and Serratia spp as the most important. We conclude that in our environment these bac­terias have a chance to be in the health services, as in the emergency department of the Clinical Hospital Viedma., Las infecciones asociadas a Servicios de Salud son una causa importante de morbilidad y mortalidad en los pa­cientes a nivel mundial. Se presentan como consecuencias de la baja calidad de atención e insuficiente supervisión y capacitación del personal. El presente trabajo tiene como objetivo evaluar la presencia de carga bacteriana en tapas de los frascos de soluciones antisépticas y pinzas de traspaso presentes en los carros de curación del servicio de emergencias del Hospital Clínico Viedma el 2015, ya que este material esta en contacto directo con los pacientes y personal de salud. El estudio es de tipo descriptivo y transversal. Para la recolección de muestras se utilizó hisopos estériles y caldo de cultivo (infusión cerebro corazón), la muestra se obtuvo de 18 tapas de los frascos de soluciones antisépticas y 5 pinzas de traspaso, se procedió a la incubación en estufa, posteriormente se procedió al sembrado en agar sangre y agar Mac-Conkey, al observar el crecimiento de colonias se realizó la tinción de Gram mediante la cual se encontró la presencia de cocos Gram negativo, bacilos Gram positivo y bacilos Gram negativo, estos últimos se sometieron a pruebas bioquímicas para su clasificación, de los cuales se encontró a Klebsiella pneumoniae y Serratia spp como las más importantes. Se concluye que en nuestro medio estas bacterias tienen una probabilidad de encontrarse en los Servicios de Salud, como en el servicio de emer­gencias del Hospital Clínico Viedma.

The Anopheles midgut hosts diverse bacterial communities and represents a complex ecosystem. Several evidences indicate that mosquito midgut microbiota interferes with malaria parasite transmission. However, the bacterial composition of salivary glands and ovaries, two other biologically important tissues, has not been described so far. In this study, we investigated the dynamics of the bacterial communities in the mosquito tissues from emerging mosquitoes until 8 days after a blood meal containing Plasmodium falciparum gametocytes and described the temporal colonization of the mosquito epithelia. Bacterial communities were identified in the midgut, ovaries, and salivary glands of individual mosquitoes using pyrosequencing of the 16S rRNA gene. We found that the mosquito epithelia share a core microbiota, but some bacteria taxa were more associated with one or another tissue at a particular time point. The bacterial composition in the tissues of emerging mosquitoes varied according to the breeding site, indicating that some bacteria are acquired from the environment. Our results revealed temporal variations in the bacterial community structure, possibly as a result of the mosquito physiological changes. The abundance of Serratia significantly correlated with P. falciparum infection both in the midgut and salivary glands of malaria challenged mosquitoes, which suggests that interactions occur between microbes and parasites. These bacteria may represent promising targets for vector control strategies. Overall, this study points out the importance of characterizing bacterial communities in malaria mosquito vectors.

The importance of extracellular DNA (eDNA) in biofilm formation has become increasingly clear from research on clinically relevant bacteria. This study aimed to determine whether the quantity of eDNA produced can be linked to the ability to form biofilm. We systematically quantified eDNA over time during planktonic growth and biofilm formation in Reinheimera sp. F8 and three other environmental isolates belonging to the genera Pseudomonas, Microbacterium and Serratia. eDNA in biofilms was visualised by fluorescence microscopy and quantified by PicoGreen® labelling without further sample preparation, whereas eDNA in planktonic cultures was precipitated before labelling and quantification. The effect of eDNA removal was investigated by DNase treatment. eDNA appeared in the early exponential growth phase of planktonic batch cultures and the concentration peaked in the stationary phase. The concentration in biofilms differed substantially between strains and over time during biofilm development. eDNA was important for the initial attachment in all strains, and DNase treatment reduced biofilm formation in three of four strains. The extent to which eDNA accumulated in planktonic cultures or biofilms did not reflect its significance to biofilm formation, and even very low concentrations of eDNA affected biofilm formation strongly. The significance of eDNA for biofilm formation in nature may thus be more widespread than previously anticipated.

Dialysis water can be contaminated by chemical and microbiological factors, all of which are potentially hazardous to patients on haemodialysis. The quality of dialysis water has seen incremental improvements over the years, with advances in water preparation, monitoring and disinfection methods, and high standards are now readily achievable in clinical practice. Advances in dialysis membrane technology have refocused attention on water quality and its potential role in the bioincompatibility of haemodialysis circuits and adverse patient outcomes. The role of ultrapure dialysate is increasingly being advocated, given its proposed clinical benefits and relative ease of production as a result of the widespread use of reverse osmosis and ultrafiltration. Many of the issues pertaining to water quality in hospital-based dialysis units are also pertinent to haemodialysis in the home. Furthermore, an increased awareness of the environmental and financial consequences of home haemodialysis has resulted in the development of automated and more efficient dialysis machines. These new machines have an increased emphasis on water conservation and recycling along with a decreased need for a complex infrastructure for water purification and maintenance. © 2012 Macmillan Publishers Limited. All rights reserved.

A national collaborative study involving the laboratories of 17 Australian hospitals examined the in vitro activity of loracarbef, cefaclor, cephalexin, amoxycillin and amoxycillin/clavulanate against 2661 recently isolated common bacterial pathogens. Loracarbef was the most active agent against Escherichia coli (MIC90 = 1 mg/l) and had activity comparable to other agents against Klebsiella pneumoniae and Proteus mirabilis. Like the oral cephalosporins, it had no activity against species of Enterobacter and Serratia. beta-lactamase-producing Staphylococcus aureus and Haemophilus influenzae were moderately sensitive to loracarbef (MIC90 = 8 mg/l for both species). Streptococcus pneumoniae was moderately sensitive to loracarbef (MIC90 = 2 mg/l) but strains which were insensitive to penicillin were often highly resistant.

Dialysis water can be contaminated by chemical and microbiological factors, all of which are potentially hazardous to patients on haemodialysis. The quality of dialysis water has seen incremental improvements over the years, with advances in water preparation, monitoring and disinfection methods, and high standards are now readily achievable in clinical practice. Advances in dialysis membrane technology have refocused attention on water quality and its potential role in the bioincompatibility of haemodialysis circuits and adverse patient outcomes. The role of ultrapure dialysate is increasingly being advocated, given its proposed clinical benefits and relative ease of production as a result of the widespread use of reverse osmosis and ultrafiltration. Many of the issues pertaining to water quality in hospital-based dialysis units are also pertinent to haemodialysis in the home. Furthermore, an increased awareness of the environmental and financial consequences of home haemodialysis has resulted in the development of automated and more efficient dialysis machines. These new machines have an increased emphasis on water conservation and recycling along with a decreased need for a complex infrastructure for water purification and maintenance. © 2012 Macmillan Publishers Limited. All rights reserved.

A national collaborative study involving the laboratories of 17 Australian hospitals examined the in vitro activity of loracarbef, cefaclor, cephalexin, amoxycillin and amoxycillin/clavulanate against 2661 recently isolated common bacterial pathogens. Loracarbef was the most active agent against Escherichia coli (MIC90 = 1 mg/l) and had activity comparable to other agents against Klebsiella pneumoniae and Proteus mirabilis. Like the oral cephalosporins, it had no activity against species of Enterobacter and Serratia. beta-lactamase-producing Staphylococcus aureus and Haemophilus influenzae were moderately sensitive to loracarbef (MIC90 = 8 mg/l for both species). Streptococcus pneumoniae was moderately sensitive to loracarbef (MIC90 = 2 mg/l) but strains which were insensitive to penicillin were often highly resistant.

Hydrogen production by microorganisms is often described as a promising sustainable and clean energy source, but still faces several obstacles, which prevent practical application. Among them, oxygen sensitivity of hydrogenases represents one of the major limitations hampering the biotechnological implementation of photobiological production processes. Here, we describe a hierarchical biodiversity-based approach, including a chemochromic screening of hydrogenase activity of hundreds of bacterial strains collected from several ecosystems, followed by mass spectrometry measurements of hydrogenase activity of a selection of the H2-oxidizing bacterial strains identified during the screen. In all, 131 of 1266 strains, isolated from cereal rhizospheres and basins containing irradiating waste, were scored as H2-oxidizing bacteria, including Pseudomonas sp., Serratia sp., Stenotrophomonas sp., Enterobacter sp., Rahnella sp., Burkholderia sp., and Ralstonia sp. isolates. Four free-living N2-fixing bacteria harbored a high and oxygen-tolerant hydrogenase activity, which was not fully inhibited within entire cells up to 150-250 lmol/L O2 concentration or within soluble protein extracts up to 25-30 lmol/L. The only hydrogenase-related genes that we could reveal in these strains were of the hyc type (subunits of formate hydrogenlyase complex). The four free-living N2-fixing bacteria were closely related to Enterobacter radicincitans based on the sequences of four genes (16S rRNA, rpoB, hsp60, and hycE genes). These results should bring interesting prospects for microbial biohydrogen production and might have ecophysiological significance for bacterial adaptation to the oxic-anoxic interfaces in the rhizosphere.

Hydrogen production by microorganisms is often described as a promising sustainable and clean energy source, but still faces several obstacles, which prevent practical application. Among them, oxygen sensitivity of hydrogenases represents one of the major limitations hampering the biotechnological implementation of photobiological production processes. Here, we describe a hierarchical biodiversity-based approach, including a chemochromic screening of hydrogenase activity of hundreds of bacterial strains collected from several ecosystems, followed by mass spectrometry measurements of hydrogenase activity of a selection of the H2-oxidizing bacterial strains identified during the screen. In all, 131 of 1266 strains, isolated from cereal rhizospheres and basins containing irradiating waste, were scored as H2-oxidizing bacteria, including Pseudomonas sp., Serratia sp., Stenotrophomonas sp., Enterobacter sp., Rahnella sp., Burkholderia sp., and Ralstonia sp. isolates. Four free-living N2-fixing bacteria harbored a high and oxygen-tolerant hydrogenase activity, which was not fully inhibited within entire cells up to 150-250 lmol/L O2 concentration or within soluble protein extracts up to 25-30 lmol/L. The only hydrogenase-related genes that we could reveal in these strains were of the hyc type (subunits of formate hydrogenlyase complex). The four free-living N2-fixing bacteria were closely related to Enterobacter radicincitans based on the sequences of four genes (16S rRNA, rpoB, hsp60, and hycE genes). These results should bring interesting prospects for microbial biohydrogen production and might have ecophysiological significance for bacterial adaptation to the oxic-anoxic interfaces in the rhizosphere.

Disease-causing microorganisms that have become resistant to drug therapy are an increasing cause of burns and wound infections. Bdellovibrio and Micavibrio are Gram-negative obligatory predators that feed on other Gram-negative bacteria. The focus of the study was to evaluate the potential application of predatory bacteria (Pb) to control human pathogens most associated with war-related infections. Our findings demonstrated that Pb are able to attack many of the pathogens tested, including bacteria from the genus Acinetobacter, Aeromonas, Aggregatibacter, Bordetella, Burkholderia, Citrobacter, Eikenella, Enterobacter, Escherichia, Klebsiella, Listonella, Morganella, Proteus, Pseudomonas, Salmonella, Serratia, Shigella, Vibrio, and Yersinia. Pb were also able to attack A. baumannii drug resistant clinical isolates obtained from Wounded Warriors. Positive predation was measured in single and multi-species microbial cultures as well as on monolayer and multilayer pre-formed biofilms grown in static and flow cell systems. The predators were also able to inhibit biofilm formation and remove metabolically inactive biofilms. Bdellovibrio and Micavibrio were shown to prey at 37 deg C but were unable to prey under oxygen limiting conditions. Our study also established that applying biofilm EPS (extracellular polymeric substance) degrading enzymes, with the Bdellovibrio, could enhance the biofilm removal aptitude of the predators. In conclusion, the work presented here highlights the potential use of predatory bacteria as biological based agent for eradicating infection and will pave the way for future studies in animal and human subjects., The original document contains color images.

Serratia spp. are Gram-negative bacteria that are similar in structure to Escherichia coli and Klebsiella spp. Serratia is resistant to most antibiotics; therefore, cure rates are very limited.

Aims To evaluate the in vitro bactericidal efficacy of lactoferrin (LF), its amidated (AMILF) and pepsin-digested (PDLF) derivatives, and their combinations, on Escherichia coli O157H7 and Serratia liquefaciens.Methods and Results PDLF exhibited the most potent bactericidal efficacy on E. coli O157H7 (>2.5 log10 CFU ml-1 reduction at concentrations ≥1 mg ml-1), and AMILF on Ser. liquefaciens (1 log10 CFU ml-1 reduction at 0.25-0.50 mg ml-1). Some combinations of LF with PDLF or AMILF showed a slight synergy on E. coli O157H7 and Ser. liquefaciens. However, all combinations of AMILF with PDLF were less active than the sum of the individual effects of the two antimicrobials. Production of capsular polysaccharide by bacteria might be involved in antimicrobial resistance.Conclusions Escherichia coli O157H7 and Ser. liquefaciens showed marked differences in the sensitivity to LF and its derivatives. E. coli O157:H7 was strongly inhibited by PDLF, whereas the effect of LF and its derivatives on Ser. liquefaciens was weak to negligible.Significance and Impact of the Study: PDLF was the most promising of the tested antimicrobials on E. coli O157:H7. However, the resistance of Ser. liquefaciens to LF and its derivatives hinders their use in the food industry. © 2010 The Authors. Letters in Applied Microbiology © 2010 The Society for Applied Microbiology.

The species Campylobacter jejuni is naturally competent for DNA uptake; nevertheless, nonnaturally transformable strains do exist. For a subset of strains we previously showed that a periplasmic DNase, encoded by dns, inhibits natural transformation in C. jejuni. In the present study, genetic factors coding for DNase activity in the absence of dns were identified. DNA arrays indicated that nonnaturally transformable dns-negative strains contain putative DNA/RNA nonspecific endonucleases encoded by CJE0566 and CJE1441 of strain RM1221. These genes are located on C. jejuni integrated elements 2 and 4. Expression of CJE0566 and CJE1441 from strain RM1221 and a homologous gene from strain 07479 in DNase-negative Escherichia coli and C. jejuni strains indicated that these genes code for DNases. Genetic transfer of the genes to a naturally transformable C. jejuni strain resulted in a decreased efficiency of natural transformation. Modeling suggests that the C. jejuni DNases belong to the Serratia nuclease family. Overall, the data indicate that the acquisition of prophage-encoded DNA/RNA nonspecific endonucleases inhibits the natural transformability of C. jejuni through hydrolysis of DNA.

BackgroundInduced resistance is a state of enhanced defensive capacity developed by a plant reacting to specific biotic or chemical stimuli. Over the years, several forms of induced resistance have been characterized, including systemic acquired resistance, which is induced upon localized infection by an avirulent necrotizing pathogen, and induced systemic resistance (ISR), which is elicited by selected strains of nonpathogenic rhizobacteria. However, contrary to the relative wealth of information on inducible defense responses in dicotyledoneous plants, our understanding of the molecular mechanisms underlying induced resistance phenomena in cereal crops is still in its infancy. Using a combined cytomolecular and pharmacological approach, we analyzed the host defense mechanisms associated with the establishment of ISR in rice by the rhizobacterium Serratia plymuthica IC1270.ResultsIn a standardized soil-based assay, root treatment with IC1270 rendered foliar tissues more resistant to the hemibiotrophic pathogen Magnaporthe oryzae, causal agent of the devastating rice blast disease. Analysis of the cytological and biochemical alterations associated with restriction of fungal growth in IC1270-induced plants revealed that IC1270 primes rice for enhanced attacker-induced accumulation of reactive oxygen species (ROS) and autofluorescent phenolic compounds in and near epidermal cells displaying dense cytoplasmic granulation. Similar, yet more abundant, phenotypes of hypersensitively dying cells in the vicinity of fungal hyphae were evident in a gene-for-gene interaction with an avirulent M. oryzae strain, suggesting that IC1270-inducible ISR and R protein conditioned effector-triggered immunity (ETI) target similar defense mechanisms. Yet, this IC1270-inducible ISR response seems to act as a double-edged sword within the rice defense network as induced plants displayed an increased vulnerability to the necrotrophic pathogens Rhizoctonia solani and Cochliobolus miyabeanus.

citrella after 48 h (74.1% average mortality). Serratia sp. caused the highest mortality after 24 h in H. convergens (40%) and C. externa (30%), whereas the Lowest mortality rates were induced at 72 h by E. aerogenes on C. externa (3%) and by Pseudomonas sp. on H. convergens (10%). The bacteria did not affect neither C. aurantiifolia or the rats, which gained the same weight as control animals.

BackgroundInduced resistance is a state of enhanced defensive capacity developed by a plant reacting to specific biotic or chemical stimuli. Over the years, several forms of induced resistance have been characterized, including systemic acquired resistance, which is induced upon localized infection by an avirulent necrotizing pathogen, and induced systemic resistance (ISR), which is elicited by selected strains of nonpathogenic rhizobacteria. However, contrary to the relative wealth of information on inducible defense responses in dicotyledoneous plants, our understanding of the molecular mechanisms underlying induced resistance phenomena in cereal crops is still in its infancy. Using a combined cytomolecular and pharmacological approach, we analyzed the host defense mechanisms associated with the establishment of ISR in rice by the rhizobacterium Serratia plymuthica IC1270.ResultsIn a standardized soil-based assay, root treatment with IC1270 rendered foliar tissues more resistant to the hemibiotrophic pathogen Magnaporthe oryzae, causal agent of the devastating rice blast disease. Analysis of the cytological and biochemical alterations associated with restriction of fungal growth in IC1270-induced plants revealed that IC1270 primes rice for enhanced attacker-induced accumulation of reactive oxygen species (ROS) and autofluorescent phenolic compounds in and near epidermal cells displaying dense cytoplasmic granulation. Similar, yet more abundant, phenotypes of hypersensitively dying cells in the vicinity of fungal hyphae were evident in a gene-for-gene interaction with an avirulent M. oryzae strain, suggesting that IC1270-inducible ISR and R protein conditioned effector-triggered immunity (ETI) target similar defense mechanisms. Yet, this IC1270-inducible ISR response seems to act as a double-edged sword within the rice defense network as induced plants displayed an increased vulnerability to the necrotrophic pathogens Rhizoctonia solani and Cochliobolus miyabeanus.

citrella after 48 h (74.1% average mortality). Serratia sp. caused the highest mortality after 24 h in H. convergens (40%) and C. externa (30%), whereas the Lowest mortality rates were induced at 72 h by E. aerogenes on C. externa (3%) and by Pseudomonas sp. on H. convergens (10%). The bacteria did not affect neither C. aurantiifolia or the rats, which gained the same weight as control animals.

La motilité de type swarming est caractérisée par la migration rapide et coordonnée d'une population bactérienne sur une surface. D s'agit d'un comportement social marqué par une différenciation en cellules hyperallongées et multiflagellées, et par la production de biosurfactant. Le swarming partage des similitudes avec le biofilm, notamment son caractère multicellulaire et une implication des systèmes de quorum sensing. L'une des caractéristiques importantes d'un biofilm est sa résistance élevée envers de nombreux agents antimicrobiens. Mes travaux ont consisté à vérifier si cette propriété se retrouvait également chez les bactéries en swarming. Cinq espèces ont été choisies: Pseudomonas aeruginosa, Bacillus subtilis, Burkholderia thailandensis, Escherichia coli et Serratia marcescens. Les profils de résistance des cellules végétatives et des cellules en swarming ont été déterminés à l'aide d'antibiogrammes couvrant divers antibiotiques de familles différentes. D a été trouvé que les bactéries en swarming présentaient une résistance accrue envers tous les antibiotiques testés, sauf les peptides antimicrobiens. Ceci indique que la résistance aux antibiotiques est effectivement une caractéristique générale du swarming. Afin de mieux caractériser le phénotype résistant des bactéries en swarming, P. aeruginosa PA14 a été choisie comme bactérie modèle. Des tests de résistance envers d'autres agents antimicrobiens comme les métaux lourds ont montré une plus grande résistance des bactéries en swarming envers l'arsenite. La résistance envers le triclosan a été observée chez les bactéries en swarming de B. subtilis et E. coli. Le triclosan n'a pas pu être testé avec P. aeruginosa étant donné sa résistance naturelle à ce biocide. Des mutants dans des pompes à efflux (gènes mexA, mexC et mexE inactivés) et un mutant dans un mécanisme de résistance associé au biofilm (gène ndvB muté) présentent la même résistance que la souche sauvage PA14, suggérant que ces mécanismes ne sont

The biosynthetic pathway of the red-pigmented antibiotic, prodigiosin, produced by Serratia sp. is known to involve separate pathways for the production of the monopyrrole, 2-methyl-3-n-amyl-pyrrole (MAP) and the bipyrrole, 4-methoxy-2,2'-bipyrrole-5-carbaldehyde (MBC) which are then coupled in the final condensation step. We have previously reported the cloning, sequencing and heterologous expression of the pig cluster responsible for prodigiosin biosynthesis in two Serratia sp. In this article we report the creation of in-frame deletions or insertions in every biosynthetic gene in the cluster from Serratia sp. ATCC 39006. The biosynthetic intermediates accumulating in each mutant have been analysed by LC-MS, cross-feeding and genetic complementation studies. Based on these results we assign specific roles in the biosynthesis of MBC to the following Pig proteins: PigI, PigG, PigA, PigJ, PigH, PigM, PigF and PigN. We report a novel pathway for the biosynthesis of MAP, involving PigD, PigE and PigB. We also report a new chemical synthesis of MAP and one of its precursors, 3-acetyloctanal. Finally, we identify the condensing enzyme as PigC. We reassess the existing literature and discuss the significance of the results for the biosynthesis of undecylprodigiosin by the Red cluster in Streptomyces coelicolor A3(2).

The biosynthetic pathway of the red-pigmented antibiotic, prodigiosin, produced by Serratia sp. is known to involve separate pathways for the production of the monopyrrole, 2-methyl-3-n-amyl-pyrrole (MAP) and the bipyrrole, 4-methoxy-2,2'-bipyrrole-5-carbaldehyde (MBC) which are then coupled in the final condensation step. We have previously reported the cloning, sequencing and heterologous expression of the pig cluster responsible for prodigiosin biosynthesis in two Serratia sp. In this article we report the creation of in-frame deletions or insertions in every biosynthetic gene in the cluster from Serratia sp. ATCC 39006. The biosynthetic intermediates accumulating in each mutant have been analysed by LC-MS, cross-feeding and genetic complementation studies. Based on these results we assign specific roles in the biosynthesis of MBC to the following Pig proteins: PigI, PigG, PigA, PigJ, PigH, PigM, PigF and PigN. We report a novel pathway for the biosynthesis of MAP, involving PigD, PigE and PigB. We also report a new chemical synthesis of MAP and one of its precursors, 3-acetyloctanal. Finally, we identify the condensing enzyme as PigC. We reassess the existing literature and discuss the significance of the results for the biosynthesis of undecylprodigiosin by the Red cluster in Streptomyces coelicolor A3(2).

Two electrochemical assays for detecting Staphylococcus aureus enterotoxin A and B genes were developed. The assays are based on PCR amplification with biotinylated primers, hybridization to a fluorescein-labeled probe, and detection with horseradish peroxidase (HRP)-conjugated anti-fluorescein antibody using a hand-held electrochemical detector. The limit of detection (LOD) for both assays was approximately 16 copies of the sea and seb genes. The assays were evaluated in blinded studies, each with 81 samples that included genomic and cloned S. aureus DNA, and genomic DNA from Alcaligens, Bacillus, Bacteroides, Bordetella, Burkholderia, Clostridium, Comanonas, Enterobacter, Enterococcus, Escherichia, Francisella, Haemophilus, Klebsiella, Listeria, Moraxella, Neisseria, Proteus, Pseudomonas, Salmonella, Serratia, Shigella, Streptococcus, Vibrio and Yersinia species. Both assays showed 100% sensitivity. The specificity was 96% for the SEA assay and 98% for the SEB assay. These results demonstrate the feasibility of performing probe-based detection of PCR products with a low-cost, hand-held, electrochemical detection device as a viable alternative to colorimetric enzyme-linked assays of PCR products., Pub. in Molecular and Cellular Probes, v18, p373-377, 2004.

Enterobacteriaceae are frequently isolated from food products and it is essential to have methods for correct identification for both food hygiene and epidemiology reasons. Phenotypic methods are not always sufficient and have to be supplemented by DNA based methods. In the present study, 70 strains of Enterobacteriaceae derived from milk, fish and meat that had previously been identified by Biolog GN Microplates were genomically classified together with 15 representative type strains of species of Enterobacteriaceae. The field strains were dominated by Hafnia alvei, Serratia liquefaciens and Rahnella aquatilis. All strains were subjected to temporal temperature gel electrophoresis (TTGE) analysis using amplicons encompassing the V3, V4 and V9 variable regions of the 16S rRNA gene. Selected strains were analysed by ribotyping and partial 16S rDNA sequencing. The type strains were differentiated into 10 different TTGE groups. Two of the groups contained two type strains. Enterobacter aerogenes and Klebsiella planticola were not distinguished due to their identical sequences and Yersinia ruckeri and Citrobacter freundii showed the same migration pattern. The 70 food strains could be differentiated into 14 TTGE groups where 33 strains (47.1%) could be assigned to TTGE groups including type or reference strains. Rabnella strains were dispersed into three TTGE groups of which one group corresponded to Rahnella genomospecies 1 and one to genomospecies 3. The grouping of Rabnella strains was supported by ribotyping and phylogenetic analysis. TTGE can be a useful additional tool for identification on the species level of food related Enterobacteriaceae., QC 20111031

The prodigiosin biosynthesis gene cluster (pig cluster) from two strains of Serratia (S. marcescens ATCC 274 and Serratia sp. ATCC 39006) has been cloned, sequenced and expressed in heterologous hosts. Sequence analysis of the respective pig clusters revealed 14 ORFs in S. marcescens ATCC 274 and 15 ORFs in Serratia sp. ATCC 39006. In each Serratia species, predicted gene products showed similarity to polyketide synthases (PKSs), non-ribosomal peptide synthases (NRPSs) and the Red proteins of Streptomyces coelicolor A3(2). Comparisons between the two Serratia pig clusters and the red cluster from Str. coelicolor A3(2) revealed some important differences. A modified scheme for the biosynthesis of prodigiosin, based on the pathway recently suggested for the synthesis of undecylprodigiosin, is proposed. The distribution of the pig cluster within several Serratia sp. isolates is demonstrated and the presence of cryptic clusters in some strains shown. The pig cluster of Serratia marcescens ATCC 274 is flanked by cueR and copA homologues and this configuration is demonstrated in several S. marcescens strains, whilst these genes are contiguous in strains lacking the pig cluster.

The prodigiosin biosynthesis gene cluster (pig cluster) from two strains of Serratia (S. marcescens ATCC 274 and Serratia sp. ATCC 39006) has been cloned, sequenced and expressed in heterologous hosts. Sequence analysis of the respective pig clusters revealed 14 ORFs in S. marcescens ATCC 274 and 15 ORFs in Serratia sp. ATCC 39006. In each Serratia species, predicted gene products showed similarity to polyketide synthases (PKSs), non-ribosomal peptide synthases (NRPSs) and the Red proteins of Streptomyces coelicolor A3(2). Comparisons between the two Serratia pig clusters and the red cluster from Str. coelicolor A3(2) revealed some important differences. A modified scheme for the biosynthesis of prodigiosin, based on the pathway recently suggested for the synthesis of undecylprodigiosin, is proposed. The distribution of the pig cluster within several Serratia sp. isolates is demonstrated and the presence of cryptic clusters in some strains shown. The pig cluster of Serratia marcescens ATCC 274 is flanked by cueR and copA homologues and this configuration is demonstrated in several S. marcescens strains, whilst these genes are contiguous in strains lacking the pig cluster.