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The aims of this study were to describe 42 cases of Clostridium perfringens type-D enterotoxaemia in cattle seen between 2003 and 2014 and to determine the diagnostic value of detecting epsilon toxin in bovine intestinal content. All cases in the series had histological brain changes considered pathognomonic for C. perfringens type-D enterotoxaemia in sheep and goats and the epsilon toxin of C. perfringens was concurrently detected in the intestinal contents of 15 (36 per cent) cases. The data from the case series indicate that intestinal epsilon toxin has a sensitivity of 56 per cent compared with histology of the brain for diagnosis of bovine C. perfringens type-D enterotoxaemia. The diagnostic specificity of detecting epsilon toxin in bovine intestinal content was investigated by screening intestinal contents of 60 bovine carcases submitted for postmortem examination. Epsilon toxin was detected in 11 (18 per cent) carcases but no pathognomonic histological brain change was found in any. The specificity of intestinal epsilon toxin was estimated to be 80.4 per cent. These studies demonstrate that for a definitive diagnosis of C. perfringens type-D enterotoxaemia in cattle histological examination of the brain is essential as the presence of epsilon toxin in the intestinal contents alone is neither sensitive nor specific enough. [ABSTRACT FROM AUTHOR]

There is no greater association between the basic science and the practice of endodontics than that of microbiology. One of the strongest factors contributing to the controversies often encountered in the endodontic field is the lack of understanding that the disease processes of the pulp and periradicular tissues generally have a microbiological etiology. The vast majority of diseases of dental pulp and periradicular tissues are associated with microorganisms. After the microbial invasion of these tissues, the host responds with both nonspecific inflammatory responses and with specific immunologic responses to encounter such infections. The aim of this study is to fill the gaps in our knowledge regarding the role of microorganisms in endodontics and to discuss in depth whether their presence in periradicular lesions is a myth or a reality. An electronic search was carried out on PubMed database (custom range of almost 50 years) and Google using specific keywords and phrases. Inclusion and exclusion criteria were specified and around 50 articles were found suitable for inclusion. Full text of all the articles was retrieved and studied. Appropriate data were extracted and pooled and finally synthesized. It is important to understand the close relationship between the presence of microorganisms and endodontic disease process to develop an effective rationale for treatment. [ABSTRACT FROM AUTHOR]

Dynamic anaerobic-aerobic feast-famine conditions are applied to wastewater treatment plants to select polyphosphate-accumulating organisms to carry out enhanced biological phosphorus removal. Acetate is a well-known substrate to stimulate this process, and here we show that different amino acids also are suitable substrates, with glycine as the most promising. 13C-labeled glycine and nuclear magnetic resonance (NMR) were applied to investigate uptake and potential storage products when activated sludge was fed with glycine under anaerobic conditions. Glycine was consumed by the biomass, and the majority was stored intracellularly as free glycine and fermentation products. Subsequently, in the aerobic phase without addition of external substrate, the stored glycine was consumed. The uptake of glycine and oxidation of intracellular metabolites took place along with a release and uptake of orthophosphate, respectively. Fluorescence in situ hybridization combined with microautoradiography using ³H-labeled glycine revealed uncultured actinobacterial Tetrasphaera as a dominant glycine consumer. Experiments with Tetrasphaera elongata as representative of uncultured Tetrasphaera showed that under anaerobic conditions it was able to take up labeled glycine and accumulate this and other labeled metabolites to an intracellular concentration of approximately 4 mM. All components were consumed under subsequent aerobic conditions. Intracellular accumulation of amino acids seems to be a novel storage strategy for polyphosphate-accumulating bacteria under dynamic anaerobic-aerobic feast-famine conditions. [ABSTRACT FROM AUTHOR]

Due to increasing resistance amongst anaerobic pathogens periodic surveillance of resistance has been recommended in regional/local settings. Anaerobic antimicrobial susceptibility testing is not routinely performed in many laboratories in Pakistan, hence absence of local data may lead to inappropriate empirical therapy in serious cases. 121 clinically significant anaerobic strains (26/121; 21% bacteremic isolates) were isolated and saved from 2010 to 2011. Susceptibility testing against metronidazole, clindamycin, co-amoxiclav, meropenem, piperacillin/tazobactam, linezolid and gatifloxacin was performed by determining minimum inhibitory concentrations (MICs). A high proportion of non-susceptible strains to metronidazole (10% of 121 isolates) and clindamycin (12% of 121 isolates) was seen, most noticeable in Bacteroides fragilis . Three Bacteroides species strains were non-susceptible to both metronidazole and clindamycin. One strain of Clostridium species was fully resistant to metronidazole and had intermediate resistance to clindamycin. No resistance to any of the other tested antibiotics was seen. Resistance to metronidazole was higher in bacteremic vs. non bacteremic isolates (p = value 0.07). In our setting where there is a high usage of empirical metronidazole and clindamycin for the treatment of serious anaerobic infections clinicians should be aware of increased resistance to these agents. Periodic surveillance of resistance to anti-anaerobic drugs especially metronidazole and clindamycin should be performed to generate antibiogram and guide appropriate empiric therapy. [ABSTRACT FROM AUTHOR]

The article discusses the extent of tetanus cases in the U.S. during January 2008 to March 2014 according to a review by the California Department of Public Health. Topics include the decline in incidence rates because of the introduction of tetanus vaccines, a definition of the confirmed case of tetanus by the Council of State and Territorial Epidemiologists (CSTE) during 2008-2010, and the importance of routine vaccination of patients every 10 years following an injury.

Harvested litchi fruit were stored under cold temperature, short-term anaerobic and pure oxygen conditions to explore the energy characteristics and the genes that are related to pericarp browning. Fruits in short-term anaerobic and pure oxygen environments were stored at 25 °C. Additionally, fruits were stored at 1 °C for 1, 2 or 3 weeks and were then subjected to a post cold storage at 25 °C for up to 48 h. Short-term anaerobic and pure oxygen storage decreased the browning index and relative abundance of the ATP synthase β subunit ( LcAtpB ) and increased respiration intensity, ATP content, the contribution of an alternate oxidation pathway to the total respiration (ρV AP /Vt) and the transcription of plant uncoupling mitochondria protein 1 ( LcUCP1 ), with short-term anaerobic treatment being more significant than pure oxygen. Cold storage decreased the ATP levels but increased the browning index, respiration intensity, ρV AP /Vt and the transcription of alternative oxidase 1 ( LcAOX1 ), LcUCP1 , ADP/ATP carrier 1 ( LcAAC1 ) and sucrose non-fermenting-1-related kinase 2 ( LcSnRK2 ) during the post storage shelf-life at 25 °C. The data suggest that the energy level is closely related to the respiratory activity and is involved in the browning control of harvested litchi fruit. Transcripts of the 5 genes were found to be involved in the energy regulation and quality control of postharvest litchi fruit. [ABSTRACT FROM AUTHOR]

The susceptibilities of 824 Bacteroides fragilis group isolates against nine antibiotics were evaluated in a Europe-wide study involving 13 countries. Species determination, by different methods, was carried out on all but one isolate. Resistance rates were evaluated according to species and geographical areas via CLSI and the European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints. The present data were compared with those obtained 10 and 20 years ago at a European level. High-level resistance (MIC ≥64 mg/L) to ampicillin was observed in 44.5% of the strains, which is a significant increase relative to 20 years ago (16%). Piperacillin/ tazobactam was more active than amoxicillin/clavulanic acid (3.1% and 10.4% resistance, respectively), again with a resistance increase relative to earlier studies. Dramatic increases in resistance were observed for cefoxitin, clindamycin and moxifloxacin, with rates of 17.2%, 32.4% and 13.6%, respectively. The lowest resistances were found for imipenem, metronidazole and tigecycline (1.2%, <1% and 1.7%). Nonsusceptible strains to imipenem and metronidazole were more resistant to other anti-anaerobic drugs. Differences were detected between geographical areas, with higher resistance rates for moxifloxacin in Scandinavian countries (21.4%) than in Mediterranean countries (5.4%), whereas, for clindamycin, the resistance rates were higher in Mediterranean (41.8%) and lower in Scandinavian countries (22.5%). Piperacillin/tazobactam resistance was also higher in Scandinavian countries. [ABSTRACT FROM AUTHOR]

1 Department of Medicine & Therapeutics, Chinese University of Hong Kong, Hong Kong; Depa... B Background b : Empyema is traditionally considered a single disease entity. O8-2: Clinical impact by phenotyping empyema based on pleural fluid culture positivity and appearance: A 7-year retrospective analysis Empyema was classified into culture-positive empyema(CPE) and culture-negative empyema(CNE); and pus-appearing empyema(PAE) and non-pus-appearing empyema(non-PAE) based on the pleural fluid culture status and macroscopic fluid appearance. [Extracted from the article]

[Display omitted] • Metronidazole was removed mainly by opening the imidazole ring for biodegradation. • Metronidazole has a stronger inhibitory effect on mesophilic fermentation. • Metronidazole specifically altered the microbial community structure. • Thermophilic fermentation was more suitable for the removal of metronidazole. Metronidazole (MNZ), an antibiotic that is specifically used for the treatment of anaerobic infections, may inhibit anaerobic fermentation. This work was designed to understand the fate and effects of MNZ in mesophilic fermentation (MF) and thermophilic fermentation (TF), respectively. The results showed that the removal of MNZ mainly occurred via biodegradation, rather than adsorption, and that MNZ could be completely degraded by opening the imidazole ring. MFs were more strongly inhibited by MNZ than TFs. MNZ concentration increased from 0 to 25 mg/L, hydrogen yield (HY) decreased from 167.5 to 16.8 mL/g glucose (90.0% decrease), and butyrate yield almost completely disappeared in MFs, whereas in TFs, HY decreased only from 101.1 to 89.3 mL/g glucose (11.7% decrease), and ethanol yield increased by 39.8%. Illumina MiSeq sequencing analysis showed that MNZ reduced the abundance of hydrogen-producing bacteria. Furthermore, the inhibition of MNZ on anaerobic fermentation was reversible. [ABSTRACT FROM AUTHOR]

Actinomycotic osteomyelitis is an infection caused by anaerobic bacteria of the Actinomyces sp. type that mainly affects soft tissues and rarely the bones. Tetracycline is an antimicrobial medication that has been used as a necrotic bone marker, easily accumulating in mineralized bones and aiding in the identification of vital and non-vital bone during surgical removal. Research conducted on the Pubmed platform found 49 articles, of which 7 were selected for analysis. The use of tetracycline as a necrotic bone marker, along with ultraviolet light, has proven advantageous in determining the extent of necrosis and optimizing surgery time, resulting in low recurrence rates and improved quality of life for the patient. [Extracted from the article]

We have developed recombinant fragment C based rapid point of care dipstick devices to assess tetanus immunization status using plasma or whole blood. The devices demonstrated specificity of 0.90 and sensitivity of 0.90 (whole blood)/0.94 (plasma) at field sites in Bangladesh and The Gambia when compared to a commercial ELISA with the immune cut-off titer set as ≥0.1 IU/mL. [ABSTRACT FROM AUTHOR]

As part of an ESCMID Study Group on Anaerobic Infections (ESGAI) project, a study was conducted to measure the antibiotic susceptibilities and corresponding gene contents of 53 Bacteroides fragilis group strains isolated in Romania. The antibiotic resistance data was comparable with the data found for other East-European countries. Here, no resistant isolate was found for imipenem, metronidazole and tigecycline. An increasing role of the cepA , cfxA and cfiA genes was observed in their corresponding antibiotic resistances. Moreover, no isolate was found that harbored the cfiA gene with a possible activating IS element. Clindamycin resistance was low, similarly to that the rate for the ermF gene. However, we did find some isolates with nimB , ermB , msrSA , linA , satG , tetX , tetM and bexA genes. This study was the first to provide antibiotic resistance data for clinical Bacteroides strains from Romania. [ABSTRACT FROM AUTHOR]

Vaccines, such as HPV vaccine, are increasingly administered to school-age children, and school-based immunization is an approach that can be used to reach these children. Limited information has thus far been published that provides an overview of the school-based approach worldwide. This article, based on self-reported data from countries, summarizes the extent to which a school-based immunization approach is used around the world, and what antigens are most frequently being administered. Of the 174 countries for which data on school-based immunization were available, ninety five countries reported using a school-based approach for immunization. Children in grades 1 and 6 (or at an age corresponding with these grades) are most often targeted, and tetanus and diphtheria toxoids are the most frequently administered antigens. The impact of the school-based approach may be reduced in areas with low school attendance, unless specific measures are taken to target out-of-school children. Methods to monitor coverage need to be standardized and data on coverage and on the reach of the approach need to be more systematically analyzed and reported. [ABSTRACT FROM AUTHOR]

This study evaluated the in vitro anti-anaerobic activity and spectrum of levornidazole, its metabolites and comparators against 375 clinical isolates of anaerobic bacteria, including Gram-negative bacilli (181 strains), Gram-negative cocci (11 strains), Gram-positive bacilli (139 strains) and Gram-positive cocci (44 strains), covering 34 species. Minimum inhibitory concentrations (MICs) of levornidazole, its five metabolites and three comparators against these anaerobic isolates were determined by the agar dilution method. Minimum bactericidal concentrations (MBCs) of levornidazole and metronidazole were measured against 22 strains of Bacteroides fragilis . Levornidazole showed good activity against B. fragilis , other Bacteroides spp., Clostridium difficile , Clostridium perfringens and Peptostreptococcus magnus , evidenced by MIC 90 values of 0.5, 1, 0.25, 2 and 1 mg/L, respectively. The activity of levornidazole and the comparators was poor for Veillonella spp. Generally, levornidazole displayed activity similar to or slightly higher than that of metronidazole, ornidazole and dextrornidazole against anaerobic Gram-negative bacilli, Gram-positive bacilli and Gram-positive cocci, especially B. fragilis . Favourable anti-anaerobic activity was also seen with levornidazole metabolites M1 and M4 but not M2, M3 or M5. For the 22 clinical B. fragilis strains, MBC 50 and MBC 90 values of levornidazole were 2 mg/L and 4 mg/L, respectively. Both MBC 50 /MIC 50 and MBC 90 /MIC 90 ratios of levornidazole were 4, similar to those of metronidazole. Levornidazole is an important anti-anaerobic option in clinical settings in terms of its potent and broad-spectrum in vitro activity, bactericidal property, and the anti-anaerobic activity of its metabolites M1 and M4. [ABSTRACT FROM AUTHOR]

Introduction Veillonella is a nonfermentative, strictly anaerobic, Gram-negative coccus that forms part of the human gastrointestinal tract, mouth and vaginal flora. Like other anaerobic infection, Veillonella species usually are involved in polymicrobial processes, which make it difficult to determine their pathogenic role. Isolation of a clinically significant Veillonella species is rare and V. parvula is the most common one reported to cause infection in humans. The most frequently reported infection caused by V. parvula is osteomyelitis, almost always in association with bacteremia. Case presentation Here, we describe a rare case of nonvertebral osteomyelitis and septicemia caused by Veillonella species in a 49-year-old Saudi man with diabetes. Initial treatment with ciprofloxacin was associated with treatment failure and poor response. Identification of the organism was essential for the selection of appropriate treatment. There have been only seven previous reports of Veillonella vertebral osteomyelitis and one report of V. parvula foot osteomyelitis with sepsis in the literature. This is the second case of Veillonella nonvertebral osteomyelitis associated with septicemia reported to date. Conclusions Veillonella species should be considered a true pathogen in diabetic patients with osteomyelitis and those with underlying immune suppression, particularly if the organism is isolated from blood. The isolation of those obligate anaerobes from blood may signal the presence of severe underlying disease and the probable need for timely surgical intervention. [ABSTRACT FROM AUTHOR]

Transfer of donor immunity after allo- HSCT is limited, requiring re-vaccination after HSCT. The CDC 2009 guidelines introduced earlier vaccination post- HSCT with a uniform vaccination strategy. This study objective was to describe predictors of immune recovery and initial response to tetanus after DTaP vaccination post- HSCT. We conducted a retrospective chart review of pediatric allo- HSCT patients transplanted between July 1, 2007-June 30, 2012 who survived >1 yr without relapse (N = 27). Response to tetanus one month after the initial dose of DTaP was defined as a ≥4 fold increase in tetanus titers ≥1 month after vaccination. Wilcoxon rank-sum exact test and Kruskall-Wallis tests were used to analyze CD4, CD8, and CD19 counts. Exact conditional logistic regression was utilized to analyze initial tetanus vaccination response. A statistically significant increase in median CD4, CD8, and CD19 counts occurred from six to 12 months post- HSCT (p ≤ 0.0001, 0.005, 0.004). Only 36% of patients had initial tetanus vaccination response at first attempt post- HSCT. None of the variables tested were statistically significant in predicting initial tetanus response to vaccination. There was no association between predictors of immune recovery or transplant variables and initial tetanus response. A uniform vaccination strategy is unlikely to provide protective antibodies for many post- HSCT patients and should be evaluated in larger studies. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the biodegradation of a mixture of pollutants commonly found in coke oven wastewater such as phenol, cresol, xylenol, quinoline, indole and cyanide under anaerobic and anoxic conditions. It was found that xylenol was highly recalcitrant under anaerobic and anoxic conditions. In presence of free cyanide (>2.5 mg/L), the organic compounds (100 mg/L) were degraded before the biodegradation of free cyanide under both the conditions. However, the biodegradation of pollutants prolonged under anaerobic conditions compared to anoxic conditions. All the organics, especially xylenol and indole, inhibited the degradation of cyanide. Experimental results highlighted the detrimental effects of the combined toxic influence of cyanide and organics on the anaerobic and anoxic microbes treating coking wastewater. The proposed mathematical model was able to simulate the biodegradation of organic compounds along with cyanide satisfactorily. [ABSTRACT FROM AUTHOR]

Peptoniphilus spp. are Gram-positive anaerobic cocci ( GPAC) that were formerly classified in the genus Peptostreptococcus. This study describes 15 cases of Peptoniphilus spp. bloodstream infection ( BSI) diagnosed from 2007 to 2011 using 16 S r DNA sequencing in patients with pneumonia, pre-term delivery, soft tissue infection or colon or bladder disease. Seven out of 15 (47%) of these cases had polymicrobial BSIs. One of the isolates was closely related to P. duerdenii (), while the other 14 isolates were most closely related to a Peptoniphilus sp. reference strain (ATCC 29743) and P. hareii (Y07839). Peptoniphilus is a rare but important cause of BSI. [ABSTRACT FROM AUTHOR]

The nitroheterocyclic classes of drugs have a long history of use in treating anaerobic infections, as exemplified by metronidazole as a first-line treatment for mild-to-moderate Clostridium difficile infection (CDI). Since direct comparisons of the three major classes of nitroheterocyclic drugs (i.e. nitroimidazole, nitazoxanide and nitrofurans) and nitrosating agents against C. difficile are under-examined, in this study their actions against C. difficile were compared. Results show that whilst transient resistance occurs to metronidazole and nitazoxanide, stable resistance arises to nitrofurans upon serial passage. All compounds killed C. difficile at high concentrations in addition to the host defence nitrosating agent S-nitrosoglutathione (GSNO). This suggests that GSNO killing of C. difficile contributes to its efficacy in murine CDI. Although nitric oxide production could not be detected for the nitroheterocyclic drugs, the cellular response to metronidazole and nitrofurans has some overlap with the response to GSNO, causing significant upregulation of the hybrid-cluster protein Hcp that responds to nitrosative stress. These findings provide new insights into the action of nitroheterocyclic drugs against C. difficile . [ABSTRACT FROM AUTHOR]

Most cases of gas gangrene caused by Clostridium species begin with trauma-related injuries but in rare cases, spontaneous gas gangrene (SGG) can occur when patients have conditions such as advanced malignancy, diabetes, or immunosuppression. Clostridium perfringens, a rare cause of SGG, exists as normal flora of skin and intestines of human. Adequate antibiotics with surgical debridement of infected tissue is the only curative therapeutic management. Mortality rate among adults is reported range of 67-100% and majority of deaths are occurred within 24 hours of onset. We experienced a case of SGG on the trunk, buttock and thigh in a neutropenic patient with acute lymphoblastic leukemia. His clinical course was rapid and fatal during pre-engraftment neutropenic period of allogeneic stem cell transplantation. [ABSTRACT FROM AUTHOR]

Objectives This prospective study was performed to determine the incidence, risk factors, severity and outcomes of community-associated Clostridium difficile infection (CA-CDI) in the SE of Scotland. Methods All patients (335) diagnosed with laboratory confirmed CDI in the city of Edinburgh, East Lothian and Midlothian regions of Scotland between August 2010 and July 2011 were followed up for one year after diagnosis. Clinical details and laboratory markers were recorded. Stool samples were tested for C. difficile, other bacterial pathogens and norovirus. Molecular epidemiology of C. difficile isolates was studied by PCR-ribotyping. Objectives This prospective study was performed to determine the incidence, risk factors, severity and outcomes of community-associated Clostridium difficile infection (CA-CDI) in the SE of Scotland. Methods All patients (335) diagnosed with laboratory confirmed CDI in the city of Edinburgh, East Lothian and Midlothian regions of Scotland between August 2010 and July 2011 were followed up for one year after diagnosis. Clinical details and laboratory markers were recorded. Stool samples were tested for C. difficile, other bacterial pathogens and norovirus. Molecular epidemiology of C. difficile isolates was studied by PCR-ribotyping. [ABSTRACT FROM AUTHOR]

Bacteroides fragilis causes the majority of anaerobic infections in humans. The presence of a pathogenicity island in the genome discriminates pathogenic and commensal B. fragilis strains. The island encodes metalloproteinase II ( MPII), a potential virulence protein, and one of three homologous fragilysin isozymes ( FRA; also termed B. fragilis toxin or BFT). Here, we report biochemical data on the structural-functional characteristics of the B. fragilis pathogenicity island proteases by reporting the crystal structure of MPII at 2.13 Å resolution, combined with detailed characterization of the cleavage preferences of MPII and FRA3 (as a representative of the FRA isoforms), identified using a high-throughput peptide cleavage assay with 18 583 substrate peptides. We suggest that the evolution of the MPII catalytic domain can be traced to human and archaebacterial proteinases, whereas the prodomain fold is a feature specific to MPII and FRA. We conclude that the catalytic domain of both MPII and FRA3 evolved differently relative to the prodomain, and that the prodomain evolved specifically to fit the B. fragilis pathogenicity. Overall, our data provide insights into the evolution of cleavage specificity and activation mechanisms in the virulent metalloproteinases. [ABSTRACT FROM AUTHOR]

Abstract: Bacteroides fragilis, an opportunistic pathogen of humans, is a leading cause of bacteraemias and anaerobic abscesses which are often treated with metronidazole, a drug which damages DNA. This study investigated the responses of the B. fragilis recA three gene operon to the stress experienced during metronidazole treatment and exposure to reactive oxygen species simulating those generated by the host immune system during infection. A transcriptionally regulated response was observed using quantitative RT-PCR after metronidazole and hydrogen peroxide treatment, with all three genes being upregulated under stress conditions. In vivo and in vitro analysis of the functional role of the second gene of the operon was done using heterologous complementation and protein expression (in Escherichia coli), with subsequent biochemical assay. This gene encoded a functional bacterioferritin co-migratory protein (BCP) which was thiol-specific and had antioxidant properties, including protection of the glutamine synthetase III enzyme. This in vitro data supports the hypothesis that the genes of the operon may be involved in protection of the bacteria from the oxidative burst during tissue invasion and may play a significant role in bacterial survival and metronidazole resistance during treatment of B. fragilis infections. [Copyright &y& Elsevier]

Purified horse anti tetanus toxin immunoglobulins with high antibody concentration and biological activity, are used as heterologous sera and standard serum for corresponding vaccine. However, the selection of precipitating agents for the purification of them is a problem in terms of purity, yield and economy, which still remains to be solved. In this study, a procedure to fractionation horse plasma anti tetanus toxin by Caprylic acid precipitation is described. A solution of acetic acid/sodium acetate was added to the samples to achieve different ionic strengths, 0.05-0.4 moles/L, and caprylic acid was added to each volume to reach final concentrations from 1 to 7% (v / v), with vigorous stirring for 60 min. Non-immunoglobulin proteins precipitated under these conditions, while immunoglobulins remained in the supernatant, which was then diafiltered to remove caprylic acid and concentrate inmunoglobulins. This methodology was compared to that based on ammonium sulfate fractionation. The best results were given when caprylic acid was added to plasma, until a final caprylic acid concentration of 3% was reached, at ionic strength 0.2 moles/L and pH adjusted to 4.5. The IgG recovery was 91-95% by using the caprylic acid method. It was achieved a protein concentration of 27.1-29.3 mg/mL and an albumin/immunoglobulins ratio of 0.019-0.021. The purity was 91-95% and the anti-tetanus toxin activity recovery of 93-96%. [ABSTRACT FROM AUTHOR]

The fate and removal of six selected endocrine disrupting compounds in a lab-scale anaerobic/aerobic (A/O) sequencing batch reactor (SBR), operating at 5 days, solids retention time (SRT) were investigated. A carbamazepine (CBZ), acetaminophen (ATP), diltiazem (DTZ), butyl benzyl phthalate (BBP), estrone and progesterone mix was spiked as model endocrine disrupting compounds (EDC) into domestic wastewater obtained from a nearby sewage treatment plant. The influent, effluent and sludge samples from the SBR unit were analysed by using an LC/MS/MS instrument equipped with electrospray ionization. More than 80% removal was observed for all the EDCs tested. It was found that biodegradation is the most important mechanism for BBP, ATP and progesterone. Biodegradation constants were calculated according to the simplified Monod model for these compounds. The DTZ seemed to have lower rate of biodegradation. The CBZ appeared totally resistant to biodegradation. However, it presented a high rate of sorption onto the sludge and was thereby treated. This contradicts with the literature studies. [ABSTRACT FROM PUBLISHER]

The OX40/CD25 assay is a novel technique that assesses antigen-specific CD4+ T-cell responses. To unequivocally demonstrate that responding cells are memory cells that become activated after secondary stimulation, naïve CD45RA+ and memory CD45RO+ populations were stimulated with cytomegalovirus (CMV) lysate and the combined expression of CD25 and OX40 measured. As expected, the naïve population showed very little response, whereas there was a higher response from the memory counterpart. To further elucidate CD4+ memory T-cell subsets involved in recall responses, CD4+ T cells were separated into central memory (Tcm) and effector memory (Tem) subsets and stimulated with antigen-pulsed antigen-presenting cells (APCs). CMV responses in healthy donors showed a Tem-dominant response with a Tem/Tcm ratio of 1.2, whereas the tetanus toxoid responses were dominated by a Tcm response with a Tem/Tcm ratio of 0.35. To determine memory response in the chronic of HIV infection, patient samples were used. A similar pattern to healthy donors was observed in seven chronic HIV+ patients at week 4 after anti-retroviral therapy who responded to CMV with a larger response coming from Tem. The pattern was similar after 48 weeks of therapy but the responses were lower in magnitude. In chronic HIV+ patients who respond to Gag peptides, following institution of therapy there was an inversion of the ratio of the responding memory subsets compared with week 4, with a greater response from Tcm at week 48. This result was concordant with reduction in antigen load. As immune activation decreased there was also a decrease in the percentage of responding effector memory cells and maintenance of long-term central memory. [ABSTRACT FROM AUTHOR]

Although anaerobic bacteria are important agents of a wide variety of serious infections, they are overlooked often in the etiology of infection due to difficulties in isolation and detection. The aim of this study was to develop a new multiplex PCR panel that could detect Bacteroides , Fusobacterium , Prevotella , Veillonella , Clostridium , Peptostreptococcus, and Actinomyces bacteria, which are the most frequently isolated from anaerobic infections, at the genus level. Aerobic and anaerobic cultures were performed on 46 clinical specimens, with suspicion of anaerobic infection and were sent to the laboratory. DNA isolation was performed with the same samples and anaerobic bacteria were detected by the multiplex PCR test developed in the study. The analytical sensitivity of the multiplex PCR assay was found to be 1–103 CFU/ml, depending on the bacterial species. In this study, anaerobic growth was observed in eight (17.4%) of 46 clinical samples. The multiplex PCR test detected 35 anaerobic bacteria from 20 (43.5%) of 46 clinical samples. The most common anaerobes isolated from clinical specimens by the multiplex PCR assay were Prevotella spp. (37.1%) and Fusobacterium spp. (22.9%) while Clostridium spp. (14.3%), Peptostreptococcus spp. (11.4%), Bacteroides spp. (8.6%), and Veillonella spp. (5.7%) followed these genera. As a result, it was concluded that the multiplex PCR panel developed in this study eliminates problems in the detection of anaerobes based on culture, provides more accurate detection of anaerobic bacteria from clinical specimens, takes a shorter time, and allows more accurate infection treatment. • Anaerobic bacteria cause serious infections in humans. • Anaerobic bacteria are difficult to isolate and detect from clinical specimens. • Anaerobes can be detected in a short time with multiplex PCR. [ABSTRACT FROM AUTHOR]

Carbapenems are an applicable subclass of β-lactam drugs in the antibiotic therapy of anaerobic infections, especially for poly-microbial cases, due to their broad antimicrobial spectrum on aerobic and anaerobic bacteria. Bacteroides fragilis is the most commonly recovered anaerobic bacteria in the clinical laboratories from mono- and poly-microbial infections. B. fragilis is relatively non-susceptible to different antibiotics, including β-lactams, tetracyclines, fluoroquinolones, and macrolides. Carbapenems are among the most effective drugs against B. fragilis strains with high-level resistance to different antibiotics. Increased antibiotic resistance of B. fragilis strains has been reported following the overuse of an antimicrobial agent. Earlier contact with carbapenems is linked with increased resistance to them that limits the options for treatment of B. fragilis caused infections, especially in cases caused by multidrug-resistant strains. Several molecular mechanisms of resistance to carbapenems have been described for different carbapenem-resistant bacteria. Understanding the mechanisms of resistance to antimicrobial agents is necessary for selecting alternative antimicrobial agents and the application of control strategies. In the present study, we reviewed the mechanisms contributing to resistance to carbapenems in B. fragilis strains. • Metallo-β-lactamase is encoded by cfiA gene in Bacteroides fragilis. • CfiA provides a high level of resistance to carbapenems. • The effect of ISs have been demonstrated on the expression of cfiA genes in B. fragilis. • Efflux pumps may contribute in resistance of B. fragilis to carbapenems. [ABSTRACT FROM AUTHOR]

The emergence of multidrug resistance in Bacteroides fragilis , especially the phylogenetic lineage carrying the carbapenemase gene cfiA , represents an increasing threat to human health. However, knowledge on the diversity of the multidrug-resistant strains and the genetic elements carrying the antibiotic resistance genes (ARGs) remains limited. The objective of the study was to describe the resistome in cfiA -positive B. fragilis. A collection of cfiA -positive B. fragilis from diverse human (8 bacteremias, 15 wound infections) and animal (2 chickens, 2 pigs, 6 dogs, 3 cats) sources in Hong Kong, 2015–2017 was analysed by whole genome sequencing. In the 36 isolates, 13 distinct ARGs (total number 83, median 2, range 0–7 per isolate) other than cfiA were detected. ARGs encoding resistance to aminoglycosides, β-lactams, macrolides, sulphonamides and tetracyclines were carried by CTn 341 -like, CTn Hyb -like, Tn 5220 -like, Tn 4555 -like and Tn 613 -like transposons and were detected in phylogenetically diverse isolates of different host sources. Only few ARGs encoding resistance to metronidazole and tetracyclines were localized on plasmids. In two chicken isolates, a novel transposon (designated as Tn 6994) was found to be involved in the dissemination of multiple ARGs mediating resistance to multiple antibiotics, including metronidazole and linezolid that are critically important for treatment of anaerobic infections. In mating experiments, Tn 6994 and the associated phenotypic resistance could be transferred to Bacteroides nordii recipient. This study illustrates the importance of transposons in the dissemination of ARGs in the cfiA -positive division of B. fragilis. One Health approach is necessary to track the dissemination of ARGs. [ABSTRACT FROM AUTHOR]

A lack of updated data on the burden and profile of anaerobic bloodstream infections (ABIs) exists. We assessed the incidence of ABIs and trends in antimicrobial resistance in anaerobes isolated from blood in Italy. We conducted a retrospective study on 17 Italian hospitals (2016–2020). Anaerobes isolated from blood culture and their in vitro susceptibility profiles (EUCAST-interpreted) were registered and analyzed. A total of 1960 ABIs were identified. The mean age of ABIs patients was 68.6 ± 18.5 years, 57.6% were males. The overall incidence rate of ABIs was 1.01 per 10.000 patient-days. Forty-seven% of ABIs occurred in medical wards, 17% in ICUs, 14% in surgical wards, 7% in hemato-oncology, 14% in outpatients. The three most common anti-anaerobic tested drugs were metronidazole (92%), clindamycin (89%) and amoxicillin/clavulanate (83%). The three most common isolated anaerobes were Bacteroides fragilis (n = 529), Cutibacterium acnes (n = 262) and Clostridium perfringens (n = 134). The lowest resistance rate (1.5%) was to carbapenems, whereas the highest rate (51%) was to penicillin. Clindamycin resistance was >20% for Bacteroides spp. , Prevotella spp. and Clostridium spp. Metronidazole resistance was 9.2% after excluding C. acnes and Actinomyces spp. Bacteroides spp. showed an increased prevalence of clindamycin resistance through the study period: 19% in 2016, 33% in 2020 (p ≤ 0.001). Our data provide a comprehensive overview of the epidemiology of ABIs in Italy, filling a gap that has existed since 1995. Caution is needed when clindamycin is used as empirical anti-anaerobic drug. • Anaerobic bloodstream infections incidence in Italy was 1.01 per 10000 patient-days. • Bacteroides fragilis was the most common isolated anaerobe (27%). • Metronidazole resistance against strictly anaerobes was 9%. • Clindamycin resistance was >20% for Bacteroides spp. , Prevotella spp. and Clostridium spp. • Clindamycin resistance increased in the study period (2016–2020) from 19 to 33%. [ABSTRACT FROM AUTHOR]

To date, antimicrobial susceptibility testing (AST) in anaerobes is highly disarrayed. The testing is not routinely performed in many laboratories to direct appropriate antimicrobial therapy, and literature on AST remains scarce. This review aims to present the current methods employed for the AST of anaerobic bacteria both in routine and research. Anaerobes are potential human pathogens and predominate the human microbiota. Despite their significant role in human health and disease, they are not paid enough heed. The educated experience-based treatment has often been instituted with anaerobic infections due to the challenging AST and relatively predictable patterns of antimicrobial resistance (AMR). However, the AMR in anaerobes remains no more predictable, especially in Gram-negative anaerobes like Bacteroides spp., where multi-drug resistance is also emerging. The changing antibiograms and the emergence of resistance determinants in anaerobes necessitate routine AST, periodic monitoring, and literature review of these organisms. The present scenario dictates to limit the empirical management of anaerobic infections and encourage consistent AST practice in routine by employing economical, faster, and more pragmatic approaches, especially in tertiary care setups that cater to a vast patient population and are held accountable for producing accurate clinical and surveillance data. The article may provide a broad perspective on the topic and different AST solutions. • Anaerobic AST is undervalued and disorderly, mainly in the Indian subcontinent. • Infrequent AST due to empirical management of anaerobes jeopardizes patient care. • The emerging MDR in anaerobes calls for regular AST for guiding treatment. • The article reviews the current methods of anaerobic AST in routine and research. • The review also focuses on the specific clinical conditions that demand the AST. [ABSTRACT FROM AUTHOR]

Highlights: [•] Most tetanus cases in Italy occur in older adults, especially elderly women. [•] Adults are not adequately protected. [•] Different case definitions for tetanus are used in different countries. [•] Clinical rather than lab-confirmed tetanus cases should be reported. [•] Strategies to improve immunity in adults are needed. [Copyright &y& Elsevier]

Background There have been few studies of pulmonary actinomycosis, which is an uncommon anaerobic infection. Consequently, the optimal therapeutic regimen, appropriate duration of treatment, long-term prognosis, and factors predicting prognosis are not well established. Methods We retrospectively reviewed the medical records of histopathologically confirmed cases of pulmonary actinomycosis seen between November 2003 and December 2012. Results The study included 68 patients with a mean age of 58.4 ± 11.6 years. Of the 68, initial surgery was performed in 15 patients (22.1%), while the remaining 53 (77.9%) received antibiotic therapy initially. In the initial antibiotic group, 45/53 (84.9%) were cured without relapse (median antibiotic duration 5.3 months). 5/53 (9.4%) patients were refractory medically (median antibiotic duration 9.7 months), and 3/53 (5.7%) experienced a recurrence (median time to relapse 35.3 months). In the initial surgery group, 14/15 (93.3%) were cured and treatment failure occurred in one (6.7%). In the multivariate analysis, the absence of an antibiotic response at 1 month was the only independent factor associated with a poor treatment outcome, with an adjusted odds ratio of 49.2 (95% CI, 3.34–724.30). There was no significant difference in treatment outcome based on the size of the parenchymal lesion, comorbidities, whether intravenous antibiotics were used, antibiotic therapy duration, or whether the initial treatment was surgical. Conclusions Antibiotic treatment with or without surgery was effective for treatment of pulmonary actinomycosis. Nevertheless, treatment failure or recurrence occurred in a considerable proportion of patients, especially those resistant to the initial antibiotic treatment. [ABSTRACT FROM AUTHOR]

Aim To quantify bacterial equivalents before and after chemomechanical preparation using 3% sodium hypochlorite ( NaOCl) and intracanal dressing with calcium hydroxide paste ( Ca(OH)2) or 2% Chlorhexidine digluconate gel ( CHX) in necrotic pulps associated or not with apical periodontitis and to further compare this quantification with counts of anaerobic microorganisms. Methodology Prospective clinical trial in 69 single-rooted adult teeth (strict inclusion criteria); CHX group: 34; Ca(OH)2 group: 35. Bacteria samples were taken at baseline ( S1), after chemomechanical preparation ( S2) and after 14 days of intracanal dressing ( S3). Bacterial equivalents were assessed by broad-range real-time polymerase chain reaction (q PCR), and live viable bacteria measured with conventional anaerobic culture ( CFU/mL). Descriptive/inferential analysis was performed with spss vs. 20.0 (α = 0.05) using the Kruskal-Wallis, Mann-Whitney and chi-squared tests and Spearman's correlation coefficients. Results Both groups showed a significant decrease between S1 and S2 (Mann-Whitney U-test; P < 0.001) both in q PCR and in culture. In the Ca(OH)2-group, no variation was observed between S2 and S3 by q PCR and culture. In contrast, the CHX group showed a significant increase from S2 to S3 by both techniques. The two groups were only significantly different in S3 (Mann-Whitney U-test; P ≤ 0.001), with a worse performance in the CHX group. Again, these results were congruent by both approaches. Data from both approaches correlate reasonably ( rS < 0.5). Conclusions Infected root canals contained a high bacterial load, and the chemomechanical root canal preparation reduced bacterial equivalents by 99.1% and anaerobic counts by 98.5%. Intracanal dressings were not efficient at reducing bacterial load, but the 14-day intracanal dressing with Ca(OH)2 performed significantly better than CHX, particularly in cases with apical periodontitis. [ABSTRACT FROM AUTHOR]

Background: Oral malodour is foul-smelling breath from the oral cavity and is due to metabolic products of bacteria in the oral cavity but can also be caused by many other systemic diseases. Oral malodour is believed to originate from foul-smelling gases, such as hydrogen sulfide produced by oral bacteria. Aim: To identify hydrogen sulfide producing bacteria from tongue biofilm and to investigate the relationship between bacterial flora and hydrogen sulphide levels in the oral cavity. Materials and Methods: Oral malodour levels in 26 subjects (aged 16-69 years) were assessed by portable volatile sulfide monitor Halimeter and gas chromatography. They were accordingly divided into two groups: an odour group and a no/low odour group. Tongue coatings were sampled and organisms were categorized. Results: Tongue coatings were spread onto sheep blood agar (anaerobic) containing Casein enzymic hydrolase, Papaic digest of soyabean meal, yeast extract, sodium chloride, L-cysteine, Hemin, and Agar at final pH (at 25°C) 7.4±°.2. The plates were incubated at 37°C for 48-72hrs aerobically and anaerobically in anaerobic chamber with mixed gas supply. Bacteria forming black or grey colonies were selected as hydrogen sulphide-producing phenotypes. The numbers of total bacteria (P < °.°5) and hydrogen sulphide-producing bacteria (P < °.°5) in the odour group were significantly larger than those in the no/low odour group. Species of Veillonella, Prevotella, Bacteriods and Peptostreptococcus were the predominant hydrogen sulphide-producing bacteria in odour group and low in no/low odour group. Conclusion: These results suggest that an increase in the number of hydrogen sulphide-producing bacteria in the tongue biofilm is responsible for oral malodour, although the bacterial composition of tongue biofilm did not differ between the two groups. [ABSTRACT FROM AUTHOR]

Abstract: This work studied the effect of three classes of veterinary antibiotics (Ceftiofur, Danofloxacin and Micospectone: a combination of Spectinomycin and Lincomycin) that are used to treat the respiratory diseases of cows and pigs on anaerobic digestion. Three different doses of antibiotics were added to a pig slurry and tested in combination with two patterns of thermal treatment performed over various times. During the anaerobic tests, such parameters as total biogas production and methane concentration in biogas were monitored. At the end of the anaerobic tests, antibiotic concentrations left in the slurries were detected. The results showed that Ceftiofur was the most degradable drug (approximately 70% of the initial content was degraded), while Danofloxacin and Lincomycin were less degradable (30–34% of the total initial content). The greatest inhibition of anaerobic digestion was observed with the drug association of Lincomycin and Spectinomycin (Micospectone), which presented the least physical degradability (heat treatment) and biological degradability. [Copyright &y& Elsevier]

Background: Oral immunization with vaccines may be an effective strategy for prevention of Clostridium difficile infection (CDI). However, application of previously developed vaccines for preventing CDI has been limited due to various reasons. Here, we developed a recombinant Lactococcus lactis oral vaccine and evaluated its effect on a C. difficile-infected animal model established in golden hamsters in attempt to provide an alternative strategy for CDI prevention. Methods: Recombinant L. lactis vaccine was developed using the pTRKH2 plasmid, a high-copy-number Escherichia coli-L. shuttle vector: 1) L. lactis expressing secreted proteins was constructed with recombinant pTRKH2 (secreted-protein plasmid) carrying the Usp45 signal peptide (SPUsp45), nontoxic adjuvanted tetanus toxin fragment C (TETC), and 14 of the 38 C-terminal repeats (14CDTA) of nontoxic C. difficile toxin A (TcdA); and 2) L. lactis expressing secreted and membrane proteins was constructed with recombinant pTRKH2 (membrane-anchored plasmid) carrying SPUsp45, TETC, 14CDTA, and the cell wall-anchored sequence of protein M6 (cwaM6). Then, 32 male Syrian golden hamsters were randomly divided into 4 groups (n = 8 each) for gavage of normal saline (blank control) and L. lactis carrying the empty shuttle vector, secreted-protein plasmid, and membrane-anchored plasmid, respectively. After 1-week gavage of clindamycin, the animals were administered with C. difficile spore suspension. General symptoms and intestinal pathological changes of the animals were examined by naked eye and microscopy, respectively. Protein levels of anti-TcdA IgG/IgA antibodies in intestinal tissue and fluid were analyzed by enzyme-linked immunosorbent assay (ELISA). A cell culture cytotoxicity neutralization assay was done by TcdA treatment with or without anti-TcdA serum pre-incubation or treatment. Apoptosis of intestinal epithelial cells was examined by flow cytometry (FL) assay. Expression of mucosal inflammatory cytokines in the animals was detected by polymer chain reaction (PCR) assay. Results: After the C. difficile challenge, the animals of control group had severe diarrhea symptoms on day 1 and all died on day 4, indicating that the CDI animal model was established in hamster. Of the 3 immunization groups, secreted-protein and membrane-anchored plasmid groups had significantly lower mortalities, body weight decreases, and pathological scores, with higher survival rate/time than the empty plasmid group (P < 0.05). The tilter of IgG antibody directed against TcdA was significantly higher in serum and intestinal fluid of secreted-protein and membrane-anchored plasmid groups than in the empty plasmid group (P < 0.05) while the corresponding titer of IgA antibody directed against TcdA had no substantial differences (P > 0.05). The anti-TcdA serum of membrane-anchored plasmid group neutralized the cytotoxicity of 200 ng/ml TcdA with the best protective effect achieved by anti-TcdA serum pre-incubation. The incidences of TcdA-induced death and apoptosis of intestinal epithelial cells were significantly reduced by cell pre-incubation or treatment with anti-TcdA serum of membrane-anchored plasmid group (P < 0.05). MCP-1, ICAM-1, IL-6, and Gro-1 mRNA expression levels were the lowest in cecum tissue of the membrane-anchored groups compared to the other groups. Conclusion: Recombinant L. lactis live vaccine is effective for preventing CDI in the hamster model, thus providing an alternative for immunization of C. difficile-associated diseases. [ABSTRACT FROM AUTHOR]

The article offers information on the isolation and identification of Mycobacterium bovis from a grey seal pup (Halichoerus grypus) undergoing rehabilitation. It discusses several facts which includes suspection of Cellulitis and a one-week course of amoxycillin or clavulanic acid was administered, possibility of deep anaerobic infection and significant bacterial growth on Columbia blood agar.

Purpose: Prior literature identified anaerobes as the predominant causative organisms in genitourinary skin and soft tissue infections. However, the increasing prevalence of community acquired, methicillin resistant Staphylococcus aureus infection has brought about the growing need to reevaluate these infections and their causative organisms. We examined the causative organisms and risk factors in suppurative superficial genitourinary infections, and evaluated the growing role of community acquired, methicillin resistant S. aureus. Materials and Methods: We performed a single institution, prospective assessment of 60 adults who presented between August 2008 and July 2010 with genitourinary skin and soft tissue infections requiring incision and drainage. Patients completed a standardized, nonvalidated questionnaire before undergoing débridement of the site. Results: A total of 60 patient specimens were obtained and 92 bacterial pathogens were isolated. Of these pathogens 55% were aerobes. S. aureus was the most predominant cultured organism, representing 25% of all cultured organisms, and 65% of these isolates were community acquired, methicillin resistant S. aureus. The most commonly associated comorbidities included diabetes mellitus, tobacco smoking and heavy alcohol use. HIV/AIDS showed a statistically significant association with community acquired, methicillin resistant S. aureus infection (OR 11.00, 95% CI 1.05-115.51, p = 0.0456), as did the cumulative number of community acquired, methicillin resistant S. aurens risk factors (OR 2.64, 95% CI 1.31-5.33, p = 0.007). Conclusions: Aerobic organisms now account for most of these infections and community acquired, methicillin resistant S. aureus has emerged as a significant causative organism. Populations that may be at increased risk for these infections include patients with diabetes mellitus, heavy alcohol users and tobacco smokers. In patients with HIV/AIDS or multiple community acquired, methicillin resistant S. aureus risk factors the latter organism is more likely to be the causative organism. [ABSTRACT FROM AUTHOR]

Little is known about the effects of manufactured nanomaterials on the function of nerves. The experiment aimed to test the effects of three different nanomaterials (1 mg l-1 of TiO2 NPs, Ag NPs or SWCNT) on the compound action potential of the shore crab ( Carcinus maenas) compared with an appropriate bulk powder or metal salt control (bulk TiO2 powder, AgNO3 and carbon black respectively). In single action potential recordings, there were no effects of any of the nanomaterials on the peak amplitude, duration, rate of rise (depolarisation), or rate of decrease (repolarisation) of the compound action potential in crab saline, despite settling of each nanomaterial directly onto the nerve preparation. The ability of the crab nerve to be stimulated to tetanus was also unaffected by exposure to the nanomaterials compared with the appropriate bulk powder or metal salt control. Solvent controls with sodium dodecyl sulfate (SDS) also had no effect on action potentials. Overall, the study concludes that there were no effects of the materials at the concentrations tested on the compound action potential of the shore crab in physiological saline. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Pediatric Infection / Çocuk Enfeksiyon Dergisi is the property of Journal of Pediatric Infection / Cocuk Enfeksiyon Dergisi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Peptoniphilus senegalensis strain JC140T sp. nov., is the type strain of P. senegalensis sp. nov., a new species within the genus Peptoniphilus. This strain, whose genome is described here, was isolated from the fecal flora of a healthy patient. P. senegalensis strain JC140T is an obli-gate Gram-positive anaerobic coccus. Here we describe the features of this organism, togeth-er with the complete genome sequence and annotation. The 1,840,641 bp long genome (1 chromosome but no plasmid) exhibits a G+C content of 32.2% and contains 1,744 protein-coding and 23 RNA genes, including 3 rRNA genes. [ABSTRACT FROM AUTHOR]

Preconditioning is defined as a range of stimuli that allow cells to withstand subsequent anaerobic and other deleterious conditions. While cell protection under preconditioning is well established, this paper investigates the influence of neuroprotective preconditioning drugs, 4-aminopyridine and bicuculline (4-AP/bic), on synaptic communication across a broad network of in vitro rat cortical neurons. Using a permutation test, we evaluated cross-correlations of extracellular spiking activity across all pairs of recording electrodes on a 64-channel multielectrode array. The resulting functional connectivity maps were analyzed in terms of their graph-theoretic properties. A small-world effect was found, characterized by a functional network with high clustering coefficient and short average path length. Twenty-four hours after exposure to 4-AP/bic, small-world properties were comparable to control cultures that were not treated with the drug. Four hours following drug washout, however, the density of functional connections increased, while path length decreased and clustering coefficient increased. These alterations in functional connectivity were maintained at four days post-washout, suggesting that 4-AP/bic preconditioning leads to long-term effects on functional networks of cortical neurons. Because of their influence on communication efficiency in neuronal networks, alterations in small-world properties hold implications for information processing in brain systems. The observed relationship between density, path length, and clustering coefficient is captured by a phenomenological model where connections are added randomly within a spatially-embedded network. Taken together, results provide information regarding functional consequences of drug therapies that are overlooked in traditional viability studies and present the first investigation of functional networks under neuroprotective preconditioning. [ABSTRACT FROM AUTHOR]

Copyright of Revista Española de Quimioterapia is the property of Sociedad Espanola de Quimioterapia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Rabbits, mice, rats, non-human primates, sheep and cattle have been used to study the effect of Clostridium perfringens enterotoxin (CPE). CPE produces mostly necrosis of the small intestinal epithelium along with fluid accumulation in rabbits and mice. In the latter, CPE can bind to internal organs such as the liver, which induces lethal potassium levels in blood. [Copyright &y& Elsevier]