1.Identification of Enteroaggregative Escherichia coli in Mongolia
Munkhdelger Ya ; Undramaa G ; Munkh-Od Ts ; Nyamaa G ; Tsatsral E ; Sarantuya J
Mongolian Medical Sciences 2015;172(2):22-27
Introduction: Enteroaggregative Escherichia coli (EAEC) is an important agent of acute and
persistent diarrhea worldwide. Few cases have been reported in healthy children. EAEC strains are
characterized by aggregative adherence (AA) to HEp-2 cells, wherein bacteria are seen in “stacked
brick” aggregates attaching to HEp-2 cells and usually to the glass surface between cells.
Goal: To identify Enteroaggregative Escherihia coli using multiplex polymerase chain reaction (PCR)
and HEp-2 adherence assay in Ulaanbaatar, Mongolia
Materials and Methods:
A total of 329 E. coli strains were isolated from stool with diarrhea in National Center for Communicable
Diseases from July 2012 through September 2014. All specimens were processed by routine
microbiological and biochemical tests in the bacteriological laboratories to identify Salmonella spp.,
Shigella spp. All specimens in our study were negative for these bacterial and parasitic pathogens.
The biofilm formation was evaluated by the growth rate of E.coli on plastic surface. PCR assays
were used to detect genes of five types of diarrheagenic E.coli (DEC). All of the DEC strains showed
mannose-resistant adherence to HEp-2 cells, and aggregative adherence was predominant in these
isolates. Bacterial susceptibility to antimicrobial agents determined by the Kirby Bauer disk diffusion
method on Muller Hinton agar.
Results:
EAEC (31.9%) was the most prevalent by PCR and HEp-2 assay comparing with others. EAEC by
multiplex PCR in samples (11, 3.3%), followed by enteropathogenic E.coli (EPEC) seen in 2.1%.
Enterohemorrhagic E.coli (EHEC) and enteroinvasive E.coli (EIEC) were found in 7 (2.1%) and 1
(0.3%) of the samples. Enterotoxigenic E.coli (ETEC) and diffusely adhering E.coli were detected
in 2 (0.6%), respectively. The evaluation of bacterial biofilm formation using 96 well plates showed
309 negative (93%), 15 weak biofilm (4.6%) and 8 moderate biofilm (2.4%) formation for E.coli and
no strong biofilm forming strain was detected. Above 50% of antibiotic resistance was observed
for ampicillin, trimethoprim/sulfamethoxazole, cefuroxime and cephalotin. Also, 95.4% of isolates
were resistant to at least three different classes of antimicrobial agents and considered as multidrug
resistance.
Conclusion:
EAEC is most prevalent pathogen among DEC in our samples. It is necessary to implement EAEC
identifying method on Hep-2 assay in our laboratory practice.
2.Relation between adherence factors and the phylogenetic group of extraintestinal pathogenic Escherichia coli
Munkhdelger Ya ; Nyamaa G ; Undarmaa G ; Oyunchimeg R ; Munguntuul T ; Altantsetseg D ; Munkh-Od Ts ; Sarantuya J
Innovation 2015;9(2):28-31
Extraintestinal pathogenic Escherichia coli (ExPEC), the specialized strains ofE.coli that cause most extraintestinal infections, represent a major but littleappreciated health threat. Phylogenetic analysis has shown that ExPEC is composedof four main phylogenetic groups (A,B1, B2, and D) and that virulent extraintestinalstrains mainly belong to groups B2 and D.In this study, we aimed to assess therelation between adherence virulence and phylogenetic groups of ExPEC.A total of 161 E.coli samples were collected. Out of these 17 (10.6%) werefrom pus, 66 (41 %) from urine, 78 (48.4%) from cervical swab. The phylogeneticgroups and 6 virulence genes (fimH, papC, papGII, papGIII, fa/draBC,andSfa/focDE) encoding adhesins were identified by triplex PCR. Phylogeneticgroups distribution was as follows: B1 10.5%, A 24.7%, B2 25.3%, and D 38.9%. Virulence genes prevalence was fimH 90.1%, papC 23%, papGII 16.8%, papGIII1.9%, Afa/draBC 11.8%, andSfa/focDE 5.6%. The cell surface protein (curli) wasdetected 50,3% by Congo red agar. In conclusion: The most isolated strainsbelonged to the phylogenetic group B2 and D. The phylogenetic groups weresignificantly associated with some genes encoding
adhesins (fimH, papC) and cellsurface protein (curli).
3. Relation between adherence factors and the phylogenetic group of extraintestinal pathogenic Escherichia coli
Munkhdelger YA ; Nyamaa G ; Undarmaa G ; Oyunchimeg R ; Munguntuul T ; Altantsetseg D ; Munkh-Od TS ; Sarantuya J
Innovation 2015;9(2):28-31
Extraintestinal pathogenic Escherichia coli (ExPEC), the specialized strains ofE.coli that cause most extraintestinal infections, represent a major but littleappreciated health threat. Phylogenetic analysis has shown that ExPEC is composedof four main phylogenetic groups (A,B1, B2, and D) and that virulent extraintestinalstrains mainly belong to groups B2 and D.In this study, we aimed to assess therelation between adherence virulence and phylogenetic groups of ExPEC.A total of 161 E.coli samples were collected. Out of these 17 (10.6%) werefrom pus, 66 (41 %) from urine, 78 (48.4%) from cervical swab. The phylogeneticgroups and 6 virulence genes (fimH, papC, papGII, papGIII, fa/draBC,andSfa/focDE) encoding adhesins were identified by triplex PCR. Phylogeneticgroups distribution was as follows: B1 10.5%, A 24.7%, B2 25.3%, and D 38.9%. Virulence genes prevalence was fimH 90.1%, papC 23%, papGII 16.8%, papGIII1.9%, Afa/draBC 11.8%, andSfa/focDE 5.6%. The cell surface protein (curli) wasdetected 50,3% by Congo red agar. In conclusion: The most isolated strainsbelonged to the phylogenetic group B2 and D. The phylogenetic groups weresignificantly associated with some genes encodingadhesins (fimH, papC) and cellsurface protein (curli).