The prevalence and antimicrobial responses of Sheila Isolates in HIV-1 infected and uninfected adult diarrhea patients in North West Ethiopia

Abstract

Abstract
Background: Shigella is one of the diarrhoea causing organisms found in HIV positive patients. But so far, the pattern
of diarrhoeal agents caused by Shigella in AIDS patients has not been determined
Objective: This study is thus aimed at determining the prevalence, antimicrobial susceptibility and resistance of Shigella
isolates in HIV positive subjects.
Methods: All stool samples taken from the subjects of this study were plated on the MacConkey agar and incubated at
35-370
C for 24 or 48 hrs. Biochemical and antimicrobial sensitivity testing were carried out by using the standard
methods.
Result: Out of the 391 subjects included in the study, 199(63.8%) HIV seropositive and 113 seronegative patients had
acute and chronic diarrhoea while 79 were HIV seropositive without diarrhoea. Of the 27 (8.7) Shigella isolates taken
from the diarrhea patients, 11 (3.5%) were from HIV positive subjects. All Shigella isolates were found to be sensitive
against norfloxacin (100%), gentamicin (97%), polymyxin B (97%) and kanamycin (93%). The most frequent resistance
observed was to chloramphenicol (62%), tetracycline (86%) and ampicillin (100%). The frequency of resistance of Amp,
Sex, Ch, TTc was found to be very high when compared with other patterns of resistance.
Conclusion: The high proportion of HIV seropositive patients who had diarrhea in the absence of identified Shigella
strains strongly indicates the existence of other diarrhoeagenic agents or mechanisms. Detailed investigation is important
to get comprehensive information for better treatment of diarrhoea in HIV /AIDS patients. According to this finding,
norfloxacin, gentamicin, polymyxin B, kanamycin and nalidixic acid might be used as drugs of choice for empirical
treatment. On the other hand, amplicilin, tetracycline and chloramphenicol may not be used as the drugs of choice for
the treatment of Shigella infection unless culture and sensitivity tests are done prior to treatment. [Ethiop.J.Health Dev.
2006;20(2):99-105]