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Here, we determined the effect of bovine lactoferrin (bLF) on the minimum inhibitory concentration (MIC) of ampicillin and trimethoprim-sulfamethoxazole in Shigella. Using a microdilution method, the MIC was determined in the presence or absence of bovine lactoferrin (10 mg/mL) on 88 Shigella strains (56 Shigella flexneri,15 Shigella boydii,13 Shigella sonnei, and 4 Shigella dysenteriae) previously isolated from peruvian children Key words: Shigella, resistance, lactoferrin, antibiotics. Nous determinons l'effet de la lactoferrine bovine (bLF) sur la concentration inhibitrice minimale (CIM) de l'ampicilline et du couple trimethoprime-sulfamethoxazole envers Shigella. En utilisant une methode de microdilution la CIM a ete determinee en presence ou en absence de bLF (10 mg/mL) sur 88 souches de Shigella (56 S. flexneri,15 S. boydii,13 S. sonnei et 4 S. dysenteriae) isolees precedemment chez des enfants peruviens de moins de deux ans. Un changement de valeur de CIM de deux fois ou plus etait considere significatif. Soixante-sept souches (76 %) etaient hautement resistantes a l'ampicilline; la presence de bLF diminuait la valeur de CIM de l'amplicilline sur le tiers des souches. Cette diminution des valeurs de CIM s'observait surtout sur les souches moins resistantes. La presence de bLF amenait sept souches resistantes a l'ampicilline (8 %) a l'interieur des limites permettant de les considerer comme sensibles. Quant au trimethoprime- sulfamethoxazole, 93 % des isolats y etaient hautement resistants, les valeurs de CIM n'etant diminuees par la bLF que sur 4 isolats seulement (5 %). Aucune souche resistante au trimethoprime-sulfamethoxazole ne devenait sensible en presence de lactoferrine. La diminution de CIM en presence de bLF semble dependre du mecanisme d'action de chaque antibiotique. Des etudes in vivo sont necessaries pour evaluer le potentiel de la bLF comme adjuvant au traitement antibiotique des souches de Shigella resistantes. Mots-cles: Shigella, resistance, lactoferrine, antibiotiques., Introduction Diarrheal diseases cause ~1.8 million deaths worldwide per year (Boschi-Pinto et al. 2008), with Shigella being one of the leading causes of diarrhea morbidity and mortality in children under [...]

Enteroaggregative Escherichia coli (EAEC) causes acute and persistent diarrhea among children, HIV-infected patients, and travelers to developing countries. We have searched for 18 genes-encoding virulence factors associated with aggregative adherence, dispersion, biofilm, toxins, serine protease autotransporters of Enterobacteriaceae (SPATEs) and siderophores, analyzed in 172 well-characterized EAEC strains (aggR +) isolated from stool samples of 97 children with diarrhea and 75 healthy controls from a passive surveillance diarrhea cohort study in Peru. Eighty-one different genetic profiles were identified, 37 were found only associated with diarrhea and 25 with control samples. The most frequent genetic profile was aggC + aatA + aap + shf + fyuA +, present in 19 strains, including diarrhea and controls. The profile set1A + set1B + pic + was associated with diarrhea (P < 0.05). Of all genes evaluated, the most frequent were aatA (CVD 342) present in 159 strains (92.4%) and fyuA in 157 (91.3%). When EAEC strains were analyzed as a single pathogen (excluding co-infections), only pic was associated with diarrhea (P < 0.05) and with prolonged diarrhea (diarrhea ≥ 7 days) (P < 0.05). In summary, this is the first report on the prevalence of a large set of EAEC virulence genes and its association with diarrhea in Peruvian children. More studies are needed to elucidate the exact role of each virulence factor. [ABSTRACT FROM AUTHOR]

Conventionally, in Escherichia coli, phylogenetic groups A and B1 are associated with commensal strains while B2 and D are associated with extraintestinal strains. The aim of this study was to evaluate diarrheagenic (DEC) and commensal E. coli phylogeny and its association with antibiotic resistance and clinical characteristics of the diarrheal episode. Phylogenetic groups and antibiotic resistance of 369 E. coli strains (commensal strains and DEC from children with or without diarrhea) isolated from Peruvian children <1 year of age were determined by a Clermont triplex PCR and Kirby-Bauer method, respectively. The distribution of the 369 E. coli strains among the 4 phylogenetic groups was A (40%), D (31%), B1 (21%), and B2 (8%). DEC-control strains were more associated with group A while DEC-diarrhea strains were more associated with group D (P<0.05). There was a tendency (P=0.06) for higher proportion of persistent diarrhea (≥14 days) among severe groups (B2 and D) in comparison with nonsevere groups (A and B1). Strains belonging to group D presented significantly higher percentages of multidrug resistance than the rest of the groups (P>0.01). In summary, DEC-diarrhea strains were more associated with group D than strains from healthy controls. [ABSTRACT FROM AUTHOR]

Here, we determined the effect of bovine lactoferrin (bLF) on the minimum inhibitory concentration (MIC) of ampicillin and trimethoprim-sulfamethoxazole in Shigella. Using a microdilution method, the MIC was determined in the presence or absence of bovine lactoferrin (10 mg/mL) on 88 Shigella strains (56 Shigella flexneri, 15 Shigella boydii, 13 Shigella sonnei, and 4 Shigella dysenteriae) previously isolated from peruvian children <2 years old. A fold change of 2 or more in MIC values was considered significant. For ampicillin, 67 (76%) strains were highly resistant; one-third of the strains (32%) showed a decrease in ampicillin MIC in the presence of LF. This was more typical of MIC values in less resistant strains. For 7 (8%) ampicillin-resistant strains, the decrease in the MIC resulted in the strains reaching the cutoff for susceptible in the presence of bLF. For trimethoprim-sulfamethoxazole, 93% of the isolates ( n = 82) were highly resistant and only 4 isolates (5%) decreased their MIC in the presence of bLF. None of the trimethoprim-sulfamethoxazole resistant strains became susceptible in the presence of LF. The decrease in the MIC in the presence of bLF seems to depend on the mechanisms of action of each antibiotic. In vivo studies are needed to further evaluate bLF as a coadjuvant to antibiotic treatment of resistant Shigella. [ABSTRACT FROM AUTHOR]

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The main aim of this study was to establish the resistance levels to antimicrobial agents, in 222 non-pathogenic E. Coli strains of fecal origin in Peru. The proportion of resistance found to the evaluated antimicrobials was ampicillin (62.6%), cotrimoxazole (48,6%), tetracycline (43,0%) and chloramphenicol (15,8%). We emphasize the high resistance levels found for quinolones: 32% for nalidixic acid (NAL) and 12% for ciprofloxacin (CIP). These high levels of quinolone-resistance in non-pathogenic strains isolated from children in this age group highlight the extensive use and the impact of the intake of this kind of antimicrobials in the community, showing the potential risk of the loss of their utility in the area. [ABSTRACT FROM AUTHOR]

Antibiotic resistance is an emerging problem worldwide present in many bacteria, specially in Escherichia coli, which has high percentages of resistance to ampicilline, thrimethoprim-sulfamethoxazole, tetracycline, chloramphenicol and nalidixic acid, which implies important complications in antibiotic treatment when required. The increasing antibiotic resistance is due to the acquisition of different molecular mechanisms of resistance through point chromosomal mutations and /or horizontal transfer of genetic material between related or different species facilitated by some genetic elements such as integrons. This review discusses the effects of the most common molecular mechanisms of antibiotic resistance in E. coli: enzymatic inactivation, changes in the target site and permeability disturbances. Getting to know the mechanisms of resistance which are involved, as the World Health Organization recommends, will allow us to improve the surveillance of the antibiotic resistance, the control policies and the antibiotic utilization at a national level. [ABSTRACT FROM AUTHOR]

Objectives. To determine the frequency and clinical features of central nervous system infections caused by enterovirus in children treated at the Hospital Nacional Cayetano Heredia in Lima, Peru. Materials and methods. A prospective, descriptive study was performed from April 2008 to March 2010. Patients aged 1 month -- 14 years with clinical diagnosis of encephalitis or aseptic meningitis were included. We investigated the presence of enterovirus, herpes simplex virus 1 (HSV-1), herpes simplex virus 2 (HSV-2) and varicella-zoster virus (VZV) by polymerase chain reaction (PCR). Results. 97 patients were included, out of which 69 % had acute encephalitis and 31 % acute meningitis. Enteroviruses were identified in 52,6% of all acute non-bacterial central nervous system infections; corresponding to 83,3 % of meningitis and 38,8 % of encephalitis. There were no cases of infection due to HSV-1, HSV-2 or VZV. Enterovirus infections reached 82,9 % in the warm months (November-January) and 28,6 % in the colder months (May-July). Conclusions. Enteroviruses are the principal etiologic agents in acute aseptic meningitis and encephalitis in pediatric patients in Lima, Peru. Enteroviruses have a seasonal epidemiological pattern with a clear increase in the number of cases during the summer months. It is useful to have this rapid diagnostic method available as an aid in the management of acute central nervous system infections. [ABSTRACT FROM AUTHOR]

Importance: Previous studies have suggested that oral lactoferrin enhances diversity in the gut microbiota in infants while inhibiting the growth of opportunistic pathogens. However, the effect of lactoferrin on infant gut microbiota over time has yet to be thoroughly studied. Our study suggests that lactoferrin oral treatment in infants aged 12-18 months does not affect gut microbiome diversity and composition over time. To our knowledge, this is the first study to report the effect of lactoferrin on infant gut microbiome composition over time and helps elucidate its impact on infant health and its therapeutic potential., Competing Interests: The authors declare no conflict of interest.

The present report is the original description of bla TEM-176. The mechanisms of resistance to antimicrobial agents were determined in an enterotoxigenic Escherichia coli, determining the susceptibility to 22 antimicrobials classified in 15 different groups by agar diffusion and establishing the phylogenetic group, mechanisms of resistance and presence of Class 1 and 2 integrons. Integrons and β-lactam resistance genes were sequenced. The isolate, belonging to phylogenetic group A, showed the presence of resistance or diminished susceptibility to a ampicillin, amoxicillin plus clavulanic acid, nalidíxic acid, ciprofloxacin, streptomycin, kanamycin, tetracycline, trimethoprim, sulfisoxazole, cotrimoxazole, azithromycin and nitrofurantoin, carrying bla TEM, aadA1/2, aphA1, sul3, tet(A) and a Class 2 integron containing a dfrA1 gene. Quinolone resistance was related to the substitution Ser83Ala. The TEM sequencing showed the presence of the new substitution Ala222Val, which led to the description of the new β-lactamase bla TEM-176.

Conventionally, in Escherichia coli, phylogenetic groups A and B1 are associated with commensal strains while B2 and D are associated with extraintestinal strains. The aim of this study was to evaluate diarrheagenic (DEC) and commensal E. coli phylogeny and its association with antibiotic resistance and clinical characteristics of the diarrheal episode. Phylogenetic groups and antibiotic resistance of 369 E. coli strains (commensal strains and DEC from children with or without diarrhea) isolated from Peruvian children <1 year of age were determined by a Clermont triplex PCR and Kirby-Bauer method, respectively. The distribution of the 369 E. coli strains among the 4 phylogenetic groups was A (40%), D (31%), B1 (21%), and B2 (8%). DEC-control strains were more associated with group A while DEC-diarrhea strains were more associated with group D (P < 0.05). There was a tendency (P = 0.06) for higher proportion of persistent diarrhea (≥ 14 days) among severe groups (B2 and D) in comparison with nonsevere groups (A and B1). Strains belonging to group D presented significantly higher percentages of multidrug resistance than the rest of the groups (P > 0.01). In summary, DEC-diarrhea strains were more associated with group D than strains from healthy controls.

Objectives: To determine the effect of bovine lactoferrin (BLF) in the formation of biofilms in clinical enteroaggregative Escherichia coli (EAEC) strains and whether this effect is independent of iron., Materials and Methods: Two methods were used: (a) qualitative, by direct observation of optical microscopy, and (b) quantitative readings of the absorbance values using ELISA reader in the presence of bLf in concentrations of 0.01 mg mL and 1 mg/mL, with and without iron and no bLf (control). Analysis occurred in 122 strains of EAEC (60 strains from children with diarrhea and 62 healthy children) previously collected in a previous study of passive surveillance of diarrhea in the Southern Cone Lima. 31 strains of the same method were used for the qualitative study., Results: (A) Qualitative method: 31 strains were evaluated with and without iron. Without iron biofi formation was 77% (24/31) in the control group versus 58% (14/31) with bLf of 0.01 mg/mL and 4% (1/31) with 1 mg/ml. Iron biofilm formation was 90% (28/31) in the control group versus 55% (17/31) with bLf of 0.01 mg/mL and 4% (1/31) with 1 mg/mL. (B) Quantitative method: without iron absorbance measured at OD 560 nm of the control group was 0.7 ± 0.5 versus 0.4 ± 0.3 with bLf 0.01 mg/mL and 0.3 ± 0.2 with bLf of 1 mg/mL (p<0.0001). This decrease in the presence of bLf included iron., Conclusions: bLf tends to decrease the formation of biofilms, showing an inhibitory effect in clinical isolates of EAEC; this effect is not iron-dependent.

The aim of this study was to develop and analyze in vitro azithromycin (AZM)-resistant mutants of Escherichia coli and Shigella boydii. Three clinical isolates of E. coli and one S. boydii isolated from feces samples collected from children under 5 years of age with diarrhea in Lima, Peru were inoculated onto Mueller-Hinton plates containing increasing serial dilutions of AZM ranging from their specific minimal inhibitory concentration (2 or 4 mg/l) to 64 mg/l. From these plates, 16 AZM-resistant mutants were selected to determine the stability of the resistance and the presence of cross resistance with other antibiotics. The role of Phe-Arg-β-Naphthylamide (PAβN)-inhibitible efflux pumps as well as the presence of mutations in the rplV, rplD, and rrlH (23S rRNA) genes and alterations in the outer membrane profiles were determined in these 16 mutants. The rate of mutation ranged from < 2.70×10(-10) to 2.17×10(-7) for E. coli and from < 9.58×10(-10) to 1.05×10(-8) for S. boydii. E. coli mutants showed an increase in the AZM-MIC up to sixfold with one strain achieving a MIC >256 mg/l. In contrast, S. boydii only presented increases of up to twofold in MIC levels. All the strains obtained, but one showed stable AZM resistance. In the presence of PAβN, the AZM MICs decreased to parental levels in Shigella mutants, while no MIC returned to parental levels among the E. coli mutants. No cross resistance to other classes of antibiotics was found. These results show the relevance of PAβN-inhibitible efflux pumps in the basal levels and development of AZM resistance. Further studies to characterize the remaining unidentified mechanisms of AZM resistance are needed.

The main aim of this study was to establish the resistance levels to antimicrobial agents, in 222 non-pathogenic E. coli strains of fecal origin in Peru. The proportion of resistance found to the evaluated antimicrobials was ampicillin (62.6%), cotrimoxazole (48,6%), tetracycline (43,0%) and chloramphenicol (15,8%). We emphasize the high resistance levels found for quinolones: 32% for nalidixic acid (NAL) and 12% for ciprofloxacin (CIP). These high levels of quinoloneresistance in non-pathogenic strains isolated from children in this age group highlight the extensive use and the impact of the intake of this kind of antimicrobials in the community, showing the potential risk of the loss of their utility in the area.

Objectives: To determine the frequency and clinical features of central nervous system infections caused by enterovirus in children treated at the Hospital Nacional Cayetano Heredia in Lima, Peru., Materials and Methods: A prospective, descriptive study was performed from April 2008 to March 2010. Patients aged 1 month - 14 years with clinical diagnosis of encephalitis or aseptic meningitis were included. We investigated the presence of enterovirus, herpes simplex virus 1 (HSV-1), herpes simplex virus 2 (HSV-2) and varicella-zoster virus (VZV) by polymerase chain reaction (PCR)., Results: 97 patients were included, out of which 69 % had acute encephalitis and 31 % acute meningitis. Enteroviruses were identified in 52,6% of all acute non-bacterial central nervous system infections; corresponding to 83,3 % of meningitis and 38,8 % of encephalitis. There were no cases of infection due to HSV-1, HSV-2 or VZV. Enterovirus infections reached 82,9 % in the warm months (November-January) and 28,6 % in the colder months (May-July)., Conclusions: Enteroviruses are the principal etiologic agents in acute aseptic meningitis and encephalitis in pediatric patients in Lima, Peru. Enteroviruses have a seasonal epidemiological pattern with a clear increase in the number of cases during the summer months. It is useful to have this rapid diagnostic method available as an aid in the management of acute central nervous system infections.

Antibiotic resistance is an emerging problem worldwide present in many bacteria, specially in Escherichia coli, which has high percentages of resistance to ampicilline, thrimethoprim-sulfamethoxazole, tetracycline, chloramphenicol and nalidixic acid, which implies important complications in antibiotic treatment when required. The increasing antibiotic resistance is due to the acquisition of different molecular mechanisms of resistance through point chromosomal mutations and /or horizontal transfer of genetic material between related or different species facilitated by some genetic elements such as integrons. This review discusses the effects of the most common molecular mechanisms of antibiotic resistance in E. coli: enzymatic inactivation, changes in the target site and permeability disturbances. Getting to know the mechanisms of resistance which are involved, as the World Health Organization recommends, will allow us to improve the surveillance of the antibiotic resistance, the control policies and the antibiotic utilization at a national level.

Unlabelled: INTRODUCTION; Diarrheagenic E. coli (DEC) are a major cause of diarrhea in children in developing countries. However, they are not part of routine diagnosis in clinical laboratories., Objectives: To determine the DEC prevalence in Peruvian children and to describe the genetic variability of these strains., Materials and Methods: A total of 8 003 E. coli strains previously isolated from eight different studies of diarrhea in children, mainly from peri-urban areas of Lima, were analyzed. Diagnosis of DEC was done with Multiplex real-time PCR using genes for each of the 6 DEC groups. Conventional PCR was performed for the detection of additional virulence genes., Results: Globally, the mean prevalence in diarrhea samples (n=4,243) was: enteroaggregative E. coli (EAEC) 9.9%, enteropathogenic E. coli (EPEC) 8.5%, enterotoxigenic E. coli (ETEC) 6.9%, diffusely adherent E. coli (DAEC) 4.8%, Shiga toxin-producing E. coli (STEC) 0.8% and enteroinvasive E. coli (EIEC) 0.6%. The relative frequency of each pathogen varies according to the age and the type of study. The main pathotypes in control samples (n=3,760) were EPEC (10.9%) and EAEC (10.4%). An important variability in the virulence genes frequency and molecular resistance mechanisms for each pathotype was found, without differences between diarrhea and control groups., Conclusions: DEC are a major cause of diarrhea in Peruvian children. These pathogens are highly heterogeneous. Additional studies are required to determine the prevalence in rural areas of Peru and in severe diarrhea cases.

Introduction: Diffusely adherent E. coli (DAEC) is the sixth recognized group of diarrheagenic E. coli. However, its association with diarrhea remains controversial. Variability in the adherence patterns of clinical strains is unknown., Objectives: To compare the adherence patterns between strains isolated from children with and without diarrhea., Materials and Methods: A total of 31 DAEC strains were analyzed, 25 from children with diarrhea and 6 from asymptomatic (control) children, isolated from a cohort study of children under one year of age in the southern districts of Lima. DAEC were identified by PCR (daaD gene). The pattern and adherence score in HEp-2 cell culture were evaluated, Actin polimerization was determined by fluorescence actin staining (FAS) and motility was evaluated by conventional microbiology methods., Results: Diffuse adherence pattern was found in 88% of diarrhea samples and in the total of control strains. The number of bacteria adhered per cell was significantly lower in diarrhea samples (p<0.05). However, actin polymerization was greater in diarrhea samples (60% vs. 17%). Motility test was positive in 60% of the diarrhea samples and in all control samples., Conclusions: Our findings suggest a difference between adherence patterns, actin polymerization and motility between DAEC strains corresponding to diarrhea and control groups. The significance of these results must be confirmed with a bigger number of strains and determining the presence of virulence genes in the strains.