ANTIBIOTIC RESİSTANCE RATES OF Shigella spp. ISOLATED FROM STOOL SAMPLES BETWEEN 2015-2024

Abstract

INTRODUCTION: Shigella spp. are one of the main causes of diarrhea, especially in children. According to the CDC, the rate of Shigella infections resistant to all known antibiotic treatments in the USA was zero in 2015, 0.4% in 2019 and 5% in 2022.In this study, we aimed to identify Shigella spp.isolated from stool samples in our hospital and to monitor their antibiotic susceptibility status. METHODS: Between January 2015 and January 2024, 28 Shigella spp.isolated from stool samples were included in the study. The isolates were identified using conventional methods,VITEK-2(bioMerieuxFrance), serogroup-specific antisera (BDDifco™,USA). Ampicillin(AMP), trimethoprim-sulfamethoxazole(TMP-SXT) and quinolone susceptibility of the strains were studied according to EUCAST recommendations. RESULTS: Of the 28 isolates,19(67.9%) were identified as S.sonnei, 8(28.6%) as S flexneri and 1(3.6%) as S.boydii.In S.sonnei,AMP, TMP-SXT and CIP resistance were detected in 57.9%, 42.1% and 5.3% of the isolates, respectively whereas in S.flexneri, the resistance rates were 87.5%, 12.5% and 12.5%, respectively(Table 1).Nine of nineteen S. sonnei isolates (47.4%) and two of eight S.flexneri isolates(25%) were positive for PTT. Among the PTT positive isolates of both S.sonnei and S.flexneri, only one isolate from each species was resistant to ciprofloxacin by gradient strip test.Only one isolate identified as S.boydii was resistant to ampicillin.In conclusion, S.sonnei was detected at a high rate (67.9%) compared to other Shigella species in this study. Ampicillin resistance was very high in both S.sonnei(57.9%) and S.flexneri(87.5%). TMP-SXT resistance was higher in S.sonnei(42.1%) than in S.flexneri. Ciprofloxacin resistance does not yet appear to be threatening in both species.

Keywords

• Shigella
• shigella sonnei
• ciprofloxacin,resistance,