Search

Enteric pathogens are commonly associated with diarrhea among malnourished children. This study aimed to determine the association between the severity of diarrheal illnesses and malnutrition among under 5-year-old children. During 2010 and 2011, we studied 2,324 under 5-year-old diarrheal children with mild disease (MD) and moderate-to-severe disease (MSD) attending a hospital in Bangladesh. Children with MSD were more likely to be malnourished compared with children with MD (35% versus 24%, P < 0.001). In multivariate analysis, malnutrition (odds ratio [95% confidence interval] = 1.53 [1.22, 1.92]), age of the child (24-59 months; 1.67 [1.28, 2.19]), fever (1.65 [1.28, 2.12]), abdominal pain (1.87 [1.48, 2.37]), straining (5.93 [4.80, 7.33]), and infection with Shigella (3.26 [2.38, 4.46]) and Vibrio cholerae (2.21 [1.07, 4.58]) were shown to be significantly associated with MSD. Factors significantly associated with malnutrition were disease severity (1.56 [1.24, 1.95]), age (24-59 months; 1.75 [1.38, 2.22]), mother's schooling (1.54 [1.16, 2.04]), and monthly household income (1.71 [1.42, 2.07]). Childhood malnutrition was associated with dysentery and dehydrating diarrhea.

From 300 stool samples, 58 Campylobacter strains were isolated by standard microbiological and biochemical methods. Of these, 40 strains were identified as Campylobacter jejuni and 5 as Campylobacter coli. The presence of flaA (100%), cadF (100%), racR (100%), dnaJ (100%), pldA (100%), ciaB (95%), virB11 (0%), ceuE (82.5%), cdtA (97.5%), cdtB (97.5%), cdtC (97.5%), and wlaN (7.5%) genes was detected in C. jejuni by PCR. All C. jejuni strains but one produced cytolethal distending toxin in a HeLa cell assay.

Every year, around 3 % of isolates from patients with diarrhoea at Dhaka Hospital, ICDDR,B, are identified as Shigella-like organisms (SLOs) based on their activity in biochemical tests. These isolates do not react with any of the current Shigella antisera including all existing and provisional serotypes. Among these SLOs, a unique cluster of seven isolates with an identical plasmid profile was found and these isolates were further characterized by phenotypic and genotypic techniques. All were nonlactose fermenters, with an identical biochemical pattern typical of Shigella dysenteriae. They were classified as invasive since they harboured the 140 MDa invasive plasmid, were able to bind Congo red, produced keratoconjunctivitis in the guinea pig eye, and were positive by PCR for the ipaH gene and Shigella enterotoxin 2 [ShET-2] gene. All isolates were resistant to ampicillin, tetracycline and sulfamethoxazole-trimethoprim but were susceptible to mecillinam, nalidixic acid, ceftriaxone and ciprofloxacin. Six of the isolates were identical in DNA pattern by PFGE with the seventh exhibiting a closely related pattern; both patterns were distinguishable from all other Shigella and Escherichia coli patterns. An antiserum prepared against one of the isolates reacted with all isolates and did not cross-react with other Shigella and E. coli serotype reference strains. It is therefore proposed that these isolates represent a new provisional serovar of S. dysenteriae, type strain KIVI 162.

Shigella sonnei is a significant cause of diarrhoeal infection in both developing and industrialized countries. From 1999 to 2003, 445 strains of Shigella sonnei were isolated from patients admitted to the diarrhoea treatment centre of the International Center for Diarrhoeal Disease Research, Bangladesh. More than 60% of the isolates were resistant to nalidixic acid, 89% to sulfamethoxazole-trimethoprim and 9.5% to ampicillin. In addition, 4% of strains were resistant to multiple antibiotics (AmpR TetR SxtR StrR) and 4.2% of strains were sensitive to all antibiotics tested. None of the strains were positive for the set1 gene, whereas 46% were positive for the sen gene. Forty-six per cent of the strains (stored at -70 degrees C) harboured the 120 MDa invasive plasmid and representative strains produced keratoconjunctivitis in the guinea pig eye. In addition, three plasmids of approximately 5, 1.8 and 1.4 MDa were found to be present in more than 90% of the strains. A self-transmissible, middle-ranged plasmid (35-80 MDa) carrying the multiple antibiotic resistance gene was found in some strains. PFGE analysis of the strains identified five unique types with many subtypes, which were characterized into four unique types by ribotyping analysis. It can be concluded that endemic strains of Shigella sonnei isolated from patients in Bangladesh are diverse in their genetic pattern.

Background: Enterotoxigenic Escherichia coli (ETEC) is a common cause of bacterial infection leading to acute watery diarrhea in infants and young children as well as in travellers to ETEC endemic countries. Ciprofloxacin is a broad-spectrum antimicrobial agent nowadays used for the treatment of diarrhea. This study aimed to characterize ciprofloxacin resistant ETEC strains isolated from diarrheal patients in Bangladesh. Methods: A total of 8580 stool specimens from diarrheal patients attending the icddr,b Dhaka hospital was screened for ETEC between 2005 and 2009. PCR and Ganglioside GM1- Enzyme Linked Immuno sorbent Assay (ELISA) was used for detection of Heat labile (LT) and Heat stable (ST) toxins of ETEC. Antimicrobial susceptibilities for commonly used antibiotics and the minimum inhibitory concentration (MIC) of nalidixic acid, ciprofloxacin and azithromycin were examined. DNA sequencing of representative ciprofloxacin resistant strains was performed to analyze mutations of the quinolone resistance-determining region of gyrA, gyrB, parC and parE. PCR was used for the detection of qnr, a plasmid mediated ciprofloxacin resistance gene. Clonal variations among ciprofloxacin resistant (CipR) and ciprofloxacin susceptible (CipS) strains were determined by Pulsed-field gel electrophoresis (PFGE). Results: Among 1067 (12%) ETEC isolates identified, 42% produced LT/ST, 28% ST and 30% LT alone. Forty nine percent (n = 523) of the ETEC strains expressed one or more of the 13 tested colonization factors (CFs) as determined by dot blot immunoassay. Antibiotic resistance of the ETEC strains was observed as follows: ampicillin 66%, azithromycin 27%, ciprofloxacin 27%, ceftriazone 13%, cotrimaxazole 46%, doxycycline 44%, erythromycin 96%, nalidixic acid 83%, norfloxacin 27%, streptomycin 48% and tetracycline 42%. Resistance to ciprofloxacin increased from 13% in 2005 to 34% in 2009. None of the strains was resistant to mecillinam. The MIC of the nalidixic acid and ciprofloxacin of representative CipR strains were 256 μg/ml and 32μg/ml respectively. A single mutation (Ser83-Leu) in gyrA was observed in the nalidixic acid resistant ETEC strains. In contrast, double mutation in gyrA (Ser83-Leu, Asp87-Asn) and a single mutation in parC (Glu84-Ly) were found in ciprofloxacin resistant strains. Mutation of gyrB was not found in either the nalidixic acid or ciprofloxacin resistant strains. None of the ciprofloxacin resistant strains was found to be positive for the qnr gene. Diverse clones were identified from all ciprofloxacin resistant strains by PFGE analysis in both CF positive and CF negative ETEC strains. Conclusion: Emergence of ciprofloxacin resistant ETEC strains results in a major challenge in current treatment strategies of ETEC diarrhea. [ABSTRACT FROM AUTHOR]