Two or more enteropathogens are associated with diarrhoea in Mexican children

Abstract

Background: Diarrhoeal diseases constitute a major public health problem, particularly in the developing world, where the rate of mortality and morbidity is very high. The purpose of this study was to conduct a 2 years and 3 months study in order to determine the prevalence of five enteropathogen diarrheogenic agents in Mexico City.

Methods: Faecal samples were obtained from 300 Mexican children diagnosed as positive for diarrhoea, aged > 2 to < 12 years old, and from 80 children matched for age but with no symptoms of the disease (control group). Two multiplex PCR were used to detect Escherichia coli, Salmonella spp., and Shigella spp. In addition, the two protozoan parasites Entamoeba histolytica/Entamoeba dispar and Giardia intestinalis were detected by conventional methods.

Results: All diarrhoeal samples were positive for one or more enteropathogens. The most common enteropathogens in diarrhoeal samples were E. histolytica/E. dispar (70.3%), Salmonella (ohio 28.3%; typhimurium 16.3%; infantis 8%; anatum 0.6%; Newport 0.3%), G. intestinalis (33%), E. coli (ETEC 13.3%; EPEC 9.3%; VTEC 8.6%; EIEC 1%) and Shigella spp. (flexneri 1.6%, sonnei 1%). Infections by two (24%) three (16%) and four (12%) pathogens were observed.

Conclusion: This study revealed that 52% of the patients were infected by more than one enteropathogen, notably E. histolitica/E. dispar and Salmonella ohio. These results are useful for clinicians to improve the empiric treatment used in such cases.

Figure 1

2.5% Agarose gel electrophoresis of E. coli amplicons obtained from diarrhoeal samples (run conditions 120 V, 94 mA, 45 min.). Lane 1: VTEC ATCC43889 and ATCC43890 strains (positive control). Lane 2: Negative control without template DNA. Lane 3: EPEC ATCC43887 strain (positive control). Lane 4: ETEC ATCC 35401 (positive control); Lane 5: EIEC ATCC43893 (positive control). Lane 6: E. coli ATCC11775 (avirulent strain, negative control). Lane 7: MWM 50-bp ladder. Lane 8: EPEC (patient group sample). Lane 9: negative sample (control group). Lane 10; negative sample (control group). Lane 11; VTEC (patient group sample). Lane 12; negative sample (patient group). Lane 13; EIEC (patient group sample). Lane 14; ETEC (patient group sample).

Figure 2

(A) 2.5% Agarose gel electrophoresis of Salmonella phase I flagellar amplicons obtained from diarrhoeal samples. Lane 1: Negative control without template DNA. Lanes 2, 3, 4 10 and 12; S. ohio (150 bp) (patient group). Lanes 5, 6 and 11; negative samples (patient group). Lane 7 S. typhimurium (patient group). Lane 8; MWM 50 bp ladder. Lane 9; S. infantis (patient group); Lane 11; Negative sample (patient group); Lane 13; Salmonella anatum (patient group). (B) 2.5% agarose gel electrophoresis of Salmonella phase II flagellar amplicons obtained from diarrhoeal samples. Lanes 1, 8 and 10, negative samples (patient group); Lane 2, Negative control without template DNA; Lane 3, Salmonella anatum (patient group); Lane 4, S. typhimurium (patient group); Lane 5, MWM 50 bp ladder; Lane 6, S. infantis (patient group); Lanes 7 and 9, S. ohio (patient group). For both electrophoresis, run conditions were 120 V, 94 mA, 45 min.