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20184
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Subject: Veterinary Public Health × End date: 2018 × Start date: 2018 ×
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    ThesisItemOpen Access
    STUDIES ON SALMONELLA SEROVARS OF ANIMAL ORIGIN WITH SPECIAL REFERENCE TO FOOD BORNE SALMONELLA SEROVARS
    (SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517502. (A.P.) INDIA, 2018-12) SURESH, YASARLA; BINDU KIRANMAYI, Ch.(MAJOR); SRINIVASA RAO, T; Srivani, M
    Salmonella is a foodborne pathogen having a worldwide public health concern. The present study was undertaken to characterize Salmonella species of animal origin based on cultural isolation, molecular confirmation of serovars, their virulence profile and antibiogram using PCR and genetic diversity studies by employing ERIC-PCR and REP-PCR. A total of 516 samples comprising poultry cloacal swabs (249), raw foods of animal origin (118 chicken samples, 65 mutton and 30 pork), 17 poultry liver swabs) and 37 poultry farm water samples were examined for presence of Salmonella serovars. Overall prevalence of Salmonella isolates was found to be 4.06% (21/516) with highest prevalence in chicken samples (6/118, 5.08%) followed by cloacal swabs of poultry (12/249, 4.81%), mutton (2 /65, 3.07%) and pork (1/30, 3.33%). All the isolates carried all the 7 virulence genes i.e. invA, invH, sopB, sopE & stn (21/21, 100%), while pefA genes was found only in S. Typhimurium isolates and sefC gene was found only in S. Enteritidis isolates (2). Antibiogram of Salmonella isolates revealed 100% susceptibility to co- trimoxazole and polymyxin–B, intermediate resistant against ampicillin (28.57%), cefotaxime (19.04%), gentamycin (14.28%), amikacin (9.52%), ceftriaxone (9.52%), ciprofloxacin (9.52%), tetracycline (4.76%) and streptomycin (4.76%) while higher resistance was observed towards amikacin (61.90%) followed by ampicillin (52.30%), tetracycline (38.09%), ceftriaxone (33.33%), gentamicin, sulfamethoxazole,cefpotaxime and nalidixic acid (28.57% each), ciprofloxacin (23.80%), doxycycline hydrochloride and chloramphenicol (19.04% each) and streptomycin (9.52%). Of the 21 Salmonella isolates, 15 isolates were found resistant to β-lactam antibiotics like ceftriaxone (33.33%), cefotaxime (28.57%), aztreonam (23.80%) and ceftazidime (23.80%) was detected. β- lactamase genes were detected in a total of 11 isolates (11/21, 52.38%), blaTEM being the predominant gene detected (9/11, 81.18%), followed by blaCTX-M group II (2/11, 18.18%), blaOXA (1/11, 9.09%) and blaCTX-M group IX (1/11, 9.09%) and no single isolate showed blaCTX-M group 1 and blaSHV genes. ERIC PCR and REP-PCR analysis revealed a greater degree of heterogeneity among S.Typhimurium and Salmonella group II isolates from different sources. ERIC PCR genotyping distinguished 7 isolates each of S.Typhimurium and Salmonella group II into 6 genotypes each whereas REP-PCR distinguished all the isolates into distinct genotypes. The discriminatory power of ERIC-PCR and REP-PCR for Salmonella isolates was found to be highly significant (>0.9) i.e. 0.952 and 1.0, respectively.
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    ThesisItemOpen Access
    DETECTION OF PROTEUS MIRABILIS IN FOODS OF ANIMAL ORIGIN, ANIMAL AND HUMAN CLINICAL SAMPLES AND WATER WITH SPECIAL EMPHASIS ON β-LACTAMASES
    (SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517502. (A.P.) INDIA, 2018-12) PRASASTHA RAM, V; VENKATESWARA RAO, L(MAJOR); SRINIVASA RAO, T; SUBRAMANYAM, K.V.
    P. mirabilis is an emerging foodborne pathogen having worldwide public health concern. The present study was undertaken to characterize P. mirabilis species of animal and human origin based on cultural isolation, PCR detection, antibiogram, virulence profiles and genetic diversity. A total of 507 samples comprising foods of animal origin (215), faecal swab samples (188), human urine samples (65), human diarrhoeic stool samples (12) as well as water samples (27) were examined. Overall prevalence of P. mirabilis was found to be 34.51% (175/507) by species-specific PCR. Among foods of animal origin, the highest rate of P. mirabilis isolates were recovered from chicken samples (38.7%), followed by pork (37.5%) and mutton samples (28.9%). Among faecal swabs of livestock, the highest rate of P. mirabilis isolates were recovered from poultry (49%), followed by pigs (37.8%). Human urine samples showed a prevalence rate of 10.7%. Water samples showed 7.4% prevalence. All the human diarrhoeic stool samples were negative for P. mirabilis. All the P. mirabilis isolates carried a combination of putative virulence genes. The genes ureC, ureA, flaA, hpmA and zapA were detected in 80.5%, 72.5%, 28.5%, 60.5% and 50.28% of P. mirabilis isolates, respectively. Antibiogram of P. mirabilis isolates revealed sensitivity towards gentamicin (76.57%), followed by ampicillin (64.57%), kanamycin (61.14%), amikacin (60.57%) and streptomycin (43.42%). Higher resistance was observed for erythromycin (71.42%), nalidixic acid (62.85%), ciprofloxacin (62.85%), tetracycline (60%), polymyxin-B (60%), cefoxitin (49.14%) and amikacin (36%). Notable percentages of isolates were intermediately resistant against streptomycin (33.14%), erythromycin (20.57%) and cefoxitin (18.28%). β-lactamase genes were detected in a total of 23 isolates (13.14%). Prevalence rates of β-lactamase genes among different samples was 23.6%, 11.1%, 10.8% and 42.8% from chicken, pork, poultry cloacal swabs and human urine samples, respectively with blaTEM being the predominant gene detected (69.56%) followed by blaOXA (26.08%), blaAmpC gene FOX (13.04%), blaCTX-M group I (4.34%), blaSHV (4.34%) and blaAmpC gene CIT (4.34%) among all the tested P. mirabilis isolates. Of the twenty-three P. mirabilis isolates analyzed, twenty-three ERIC-PCR patterns and twenty-two REP-PCR patterns were obtained. A pair of P. mirabilis isolates (13 and 14) that had identical REP-PCR pattern (R13) were distinguished by ERIC-PCR into two different genotypes (E13 and E14). The two P. mirabilis isolates sharing identical REP-PCR pattern (R13) but differential ERIC-PCR pattern (E13 and E14) were recovered from poultry cloacal swabs (PC 4 and PC 5) collected from LFC, Gannavaram. The discriminatory power ERIC-PCR and REP-PCR for P. mirabilis isolates was found to be 1 and 0.996, respectively. Close clustering between P. mirabilis of animal and human origin are indicative of probable zoonotic significance.
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    ThesisItemOpen Access
    CHARACTERIZATION OF Campylobacter SPECIES OF ANIMAL AND HUMAN ORIGIN
    (SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517502. (A.P.) INDIA, 2018-12) SRINIVAS, K; SRINIVASA RAO, T(MAJOR); BINDU KIRANMAYI, Ch.; LAKSHMI KAVITHA, K
    Campylobacter is a well established food-borne zoonotic pathogen having a worldwide public health importance. The present study was undertaken to characterize Campylobacter species of animal and human origin based on cultural isolation. A total of 513 samples comprising faecal samples of livestock and poultry (174), intestinal contents of livestock and poultry (96), foods of animal origin (185) and human diarrhoeic samples (35) as well as samples of miscellaneous origin (23) were examined. Overall prevalence of Campylobacter spp. was found to be 4.87% (25/513) with highest prevalence in poultry intestinal samples (8/36, 22.2%), followed by pig intestinal contents (4/40, 10%), pig faecal samples (5/60, 8.33%), pork samples (3/90, 3.33%), human diarrhoeic samples (1/35, 2.85%), poultry faecal samples (3/114, 2.63%) and chicken meat samples (1/50, 2%). All 7 virulence genes under the study (iam, virB11, flaA, cadF, cdtA, cdtB, cdtC) were detectable. flaA and cadF genes were present in all the isolates (25/25, 100%) followed by iam (23/25, 92%), cdtA (20/25, 80%), cdtB (20/25, 80%), cdtC (17/25, 68%) and virB11 (4/25, 16%). Antibiogram profiling of 25 isolates revealed that a major fraction of the Campylobacter isolates showed sensitivity to colistin and co-trimoxazole (64%), chloramphenicol and azithromycin (56%) and ceftazidime (52%). All the Campylobacter isolates were resistant to at least one of the antibiotics tested. Higher resistance was observed for vancomycin and tetracycline (76%), cephalothin and ciprofloxacin (68%), erythromycin (56%) and doxycycline (52%). Notable percentages of isolates were intermediately resistant against nalidixic acid and nitrofurantoin (44%), gentamicin and streptomycin (32%) and clindamycin (28%). Resistance to β-lactam antibiotics like aztreonam (40%), cefotaxime (32%), ceftriaxone (40%) and ceftazidime (28%) were detected. ESBL production was confirmed phenotypically in 12 isolates by CDM . blaTEM was the only β-lactamase gene detected in 60% of the isolates. rep-PCR (ERIC-PCR and REP-PCR) and flaA-PCR-RFLP analysis revealed a greater degree of molecular heterogeneity among Campylobacter isolates from different sources. ERIC-PCR genotyping revealed 6 and 18 genotypes distinguished among 6 and 19 isolates of C. jejuni and C. coli, respectively. REP-PCR genotyping revealed 5 and 19 genotypes among 6 and 19 isolates of C. jejuni and C. coli., respectively while flaA PCR-RFLP typing of 6 isolates of C. jejuni and 19 C. coli isolates revealed 5 and 15 genotypes, respectively. The discriminatory power of the three typing methods for Campylobacter species were found to be highly significant (>0.90) i.e. 0.9967 (ERIC PCR and REP-PCR) and 0.9833 (flaA-PCR-RFLP). Cluster analysis revealed a great deal of homogeneity and heterogeneity among different isolates recovered from various sources and hinted at the chance of cross-contamination of foods of animal origin.
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    ThesisItemOpen Access
    DETECTION OF EXTENDED SPECTRUM βLACTAMASES IN SHIGA TOXIN PRODUCING ESCHERICHIA COLI ISOLATED FROM DIFFERENT RAW MEAT SAMPLES
    (SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517502. (A.P.) INDIA, 2018-10) PRABHU KISHORE, G; SRINIVASA RAO, T(MAJOR); BINDU KIRANMAYI, Ch.; RAMANI PUSHPA, R.N.
    Shiga toxin producing Escherichia coli is an important foodborne pathogen having worldwide public health concern. The present study was undertaken to characterize STEC from raw meats of animal origin and human origin based on cultural and biochemical isolation, PCR detection, virulence profiles, antibiogram, serotyping and genetic diversity. A total of 523 samples comprising raw foods of animal origin (470) and human diarrhoeic stools (53) were examined. Out of 523 total samples collected, 178 (34.03%) samples were positive for Escherichia coli by cultural and molecular methods. Out of 178 E. coli isolates, 154/470 (32.76%) isolates were from raw foods of animal origin and 24/53 (45.28%) from human diarrhoeic stool samples.Out of 470 food samples screened,the highest rate of E. coli isolation was recorded from mutton (47.27%, 26/55), followed by cara beef (33.33%, 13/39) and chicken (30.58%, 115/376). Out of a total of 178 E. coli isolates, m-PCR revealed 43 (24.1%) isolates as STEC. Among the 43 STEC isolates, 9 (34.6%) were from mutton samples, 6 (46.1%) cara beef samples, 19 (16.5%) chicken samples and 9 (37.5%) human isolates. The genes stx1, stx2, eaeA and hlyAwere detected in 93.02%, 39.53%, 44.18% and 46.51% of STEC isolates, respectively. Two mutton samples showed all the four targeted genes in present study. Antibiogram study of STEC isolates revealed sensitivity towards fosfomycin (100%) chloramphenicol (95.3%), gentamicin (55.8%) and Amikacin (53.4%). Higher resistance was observed for vancomycin (100%), erythromycin (100%), streptomycin (100%), ciprofloxacin (95.3%), naladixic acid (93%), Ampicillin (90.6%), cefotaxime (86%), ceftazidime (81.3%), ceftriaxone (74.1%) and co-trimoxazole (58.1%). Notable percentages of isolates were intermediately resistant against norfloxacin (32.5%), kanamycin and tetracycline (27.9% each)and aztreonam (16.2%). ESBL phenotypes were confirmed in a total of 21 STEC isolates using phenotypic confirmation tests. β-lactamase genes were detected in a total of 21(48.8%) STEC isolates, with blaTEM being the predominant gene detected (25.5%, 11/43) followed by blaCTX-M group I (20.9%, 9/43), blaOXA(13.9%, 6/43), blaSHV(9.3%, 4/43), blaCTX-M group II ( 4.6%, 2/43) and no single isolate showed blaAmpCgene among all the tested STEC isolates. Prevalence rates of βlactamase genes among different samples is 57.8%, 44.4%, 50% and 33.3% among the STEC isolates obtained from raw meat of chicken, mutton, cara beef and human diarrhoeic stool samples, respectively. CTX-M beta-lactamase was found to be the most frequent mechanism of ESBL resistance in STEC isolates of the present study. All the 21 ESBL producing STEC isolates were sent for serotyping on the basis of ‘O’ antigen and 9 of them were belonging to serotype O22, 4 were serotype O88 and others were ONT. ERIC PCR and REP-PCR analysis revealed a greater degree of heterogeneity among STEC isolates from different and within the same sources. Of the 21 ESBL producing STECisolates analyzed, 21 ERIC-PCR patterns and 21 REP-PCR patterns were obtained by using ERIC and REP-PCR analysis, respectively. The discriminatory power for both ERIC and REP-PCR was found to be 0.999. Genetic diversity of STEC recovered from foods of animal origin and humans in India adds to the heterogeneity reports among STECspecies world-wide, supporting diversity among same species. Close clustering between STECfrom raw meats of animal origin and human origin is apossible indicative of probable cross contamination and its zoonotic significance.