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20242
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Subject: Veterinary Public Health × End date: 2024 × Start date: 2024 ×
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    ThesisItemOpen Access
    DETECTION OF VIRULENCE GENE PROFILE AND ESBL PRODUCTION IN Shigella spp. FROM FOODS OF ANIMAL ORIGIN
    (SRI VENKATESWARA VETERINARY UNIVERSITY, TIRUPATI - 517 502. (A.P.) INDIA, 2024-02) SRAVYA DEEPIKA GUNTI; SUBHASHINI .N (MAJOR); BINDU KIRANMAYI .CH; SUDHAKAR .K
    The present study was undertaken for isolation and characterization of Shigella spp. from foods of animal origin. A total of 367 samples from wide range of foods of animal origin comprising of chicken (70), mutton (80), pork (50), fish (65), raw milk samples (65), spoiled eggs contents (12) and fresh eggs contents (25). Out of 367 samples analyzed, 15.2% (56/367) and 1.3% (5/367) samples were positive for Shigella spp. by cultural isolation and m-PCR, respectively. All the five S. dysenteriae isolates were detected from egg samples. None of the isolates exhibited biofilm production ability on congo red agar and 60% Shigella isolates showed lipase activity with clear zone around the colonies on Tween20 agar. All the isolates carried the virulence gene virA (100%) followed by sat (80%), set1A (60%) and Ial and set1B (40% each) whereas stx and sen genes were not found in any of the Shigella spp. Antibiogram of five isolates revealed 100% resistance towards Penicillin-G (100%), followed by ampicillin and amikacin (80% each), tetracycline and streptomycin (60% each), cefoxitin, azithromycin, chlormphenicol and nalidixic acid (40% each) and gentamicin, ciprofloxacin and nitrofurantoin (20% each). Higher sensitivity was observed towards ciprofloxacin (80%), followed by nalidixic acid (60%), tetracycline, nitrofurantoin, chlormphenicol and azithromycin (40% each) and gentamicin, streptomycin and ampicillin (20% each). All five S. dysenteriae isolates (100%) isolates were found to be multi drug resistant (MDR). A total of two (40%) isolates were phenotypically confirmed as ESBL producers and none of the isolates showed any of the β-lactamase genes under study. ERIC-PCR and REP-PCR genotyping distinguished five isolates of S. dysenteriae into five genotypes revealed a greater degree of heterogeneity. The discriminatory power of ERIC-PCR and REP-PCR was found to be one, indicating that both the genotyping methods were highly significant. Cluster analysis also revealed a great degree of homogeneity and heterogeneity among different isolates recovered from different sources, thereby indicating possible chance of interactions among different environments.
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    ThesisItemOpen Access
    ANTIMICROBIAL RESISTANCE, VIRULENCE AND GENOTYPIC PROFILING OF Clostridium difficile ISOLATED FROM ANIMALS AND HUMANS
    (SRI VENKATESWARA VETERINARY UNIVERSITY, TIRUPATI - 517 502. (A.P.) INDIA, 2024-02) NAGARJUNA REDDY NAKKA; SRINIVASA RAO .T (MAJOR); BINDU KIRANMAYI .CH; SUDHA RANI CHOWDARY .CH
    The present study was undertaken for isolation and characterization of Clostridium difficile from food animals, foods of animal origin, environmental samples and human samples. Out of 400 samples analyzed, 15% (60/400) were positive for C. difficile by cultural isolation and confirmation by biochemical tests. Out of 60 phenotypically positive isolates from different sources, 11 (18.33%) isolates were further confirmed by species specific PCR targeting genes (tpi and gluD genes) The highest rate of occurrence of C. difficile was obtained in chicken samples 8.0% (4/50), while lowest in mutton samples 2% (1/50). All the C. difficile isolates (100%) showed gelatinase activity, 45.45% isolates exhibited congo red binding activity, none of the isolates were positive for lecithinase activity on on egg yolk agar. Eight C. difficile isolates (72.72%) carried both toxin A and toxin B, two (18.18%) isolates carried only toxin B, 10 (90.91%) isolates carried binary toxin and one (9.09%) isolate from diarrhoeic stools of vety students did not carry any of the toxins. Among 11 C. difficile isolates higher resistance was observed towards pencillin G and linezolid (100% each), followed by gentamicin (81.81%), cefotaxime and clindamycin (72.72% each) and ciprofloxacin (63.63%). The highest sensitivity was observed for chloramphenicol (100%) followed by metronidazole and vancomycin (81.81% each), moxifloxacin (72.72%) and meropenem (54.54%). Intermediate resistance pattern were observed against ceftriaxone and tetracycline (18.18% each). All the C. difficile isolates were MDR and MAR indexing of all isolates yielded 6 MAR index groups. Out of 11 C. difficile isolates nine were identified as ESBL suspects by PST and ESBL production was confirmed in nine (81.81%) isolates by CDM and in eight (72.72%) isolates by DDST. All the 9 phenotypic ESBL suspects did not carry any of the beta lactamase genes (blaTEM, blaSHV and blaOXA) by multiplex PCR. Among 11 C. difficile isolates, three (27.27%) isolates carried tetM genes, two (18.18%) isolates carried vanC1 gene and none of the isolates carried aac-aph genes by PCR. A greater degree of heterogeneity was observed among 11 C. difficile isolates from different sources by REP-PCR. Genotyping of C. difficile by REP-PCR was highly significant since the discriminatory power is one. Cluster analysis also revealed a greater degree of homogeneity and heterogeneity among different isolates recovered from different sources.