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Open 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.
Open 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.
Open 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.
Open 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.
Open Access
STUDIES ON PESTICIDE RESIDUES IN WATER, SOIL, FODDER AND MILK ALONG MUST RIVER BELT
(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2013-10) KOTINAGU, KORRAPATI; KRISHNAIAH, N(MAJOR); MADAHAVA RAO, T; KONDAL REDDY, K; SASHI BHUSHAN, V
ABSTRACT: A study was conducted to estimate residues of certain pesticides of organochlorines viz., DDT (o,p'- DDE, o,p' - DDD, p,p'- DDT and o,p'- DDT and Dicofol), HCH (Alpha, Beta, Gamma, Delta), cyclodiene compounds (Aldrin, Endosulfan Sulphate and Heptachlor) and organophosphates (Triazophos, Dimetheoate, Chlorpyrifos and Methyl-chlorpyrifos) in soil, water, fodder and milk samples collected from six zones of Musi river belt area. To evaluate the pollution level of Musi river, the river belt was divided in to six zones viz., Zone 1 (Attapur to High court), Zone 2 (Chadhar ghat to Uppal), Zone 3 (Peerzadiguda to Chinna viralla), Zone 4 (Pillai Palli to Alinagar), Zone 5 (Indriyala to Manimadde), Zone 6 (Musi reservoir to Wazirabad). Only soil samples collected hm Zone 1 showed residual levels (in ppm) of 0.06 + 0.005 (0.035 to 0.083), 0.73 * 0.01 (0.675 to 0.791), 1.27 * 0.09 (1.023 to l.893), 0.14 =k 0.015 (0.098 to 0.243) and 0.55 * 0.02 (0.481 to 0.685) for p,p'- DDE, o,p'- DDD, p,p'- DDT, o,p' - DDT and Total DDT respectively. Dicofol was present only in fodder samples of zone 5 at concentration of 0.07 + 0.0007 (0.071 to 0.077). Among HCH compounds only delta HCH was found in soil samples of Zone 1 at a concentration of 0.08 *0.003 (0.065 to 0.098). Water, fodder and milk samples from zone 2 to 6 did not contain any residues of DDT and HCH. None of the samples water, soil, fodder and Milk from all the 6 zones contain the residues of Cyclodiene compounds. Among organophosphorus compounds Triazophos was present in soil samples of zone 1 at a level of 0.03 * 0.001 (0.032 to 0.045) and Dimetheoate was present in milk samples collected from Zone 6 at a level of 0.13 & 0.006 (0.1 11 to 0.167). From this study, it can be concluded that all the pesticide residues in soil were well below the MRL values, whereas Dicofol in fodder and Dimethoate in milk were slightly above the MRL values specified by EU and CODEX.
Open Access
IN VITRO EVALUATION OF DIFFERENT LACTIC ACID BACTERIAL STRAINS FOR THEIR PROBIOTIC CHARACTERISTICS
(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2012-11) SRINU, B; MADHAVA RAO, T(MAJOR); SHASHI KUMAR, M; KONDAL REDDY, K
ABSTRACT : Identifying probiotic characteristics of bacterial strains by in vitro studies forms basis for selection of functional probiotics for commercial use. The objective of study was to collect different cultures and screen to study their functional probiotic characteristics such as acid tolerance, bile tolerance, antibacterial activity, antibiotic sensitivity, temperature tolerance and acidifying activity. Among the eighteen Lactic acid bacterial strains studied, 15 showed good survivability at high bile salt concentration (0.3 to 2 % oxgall) and good growth at a pH of 1.5 to 3.5. These probiotic species showed good survival abilities in acidic pH 2.0 to 3.5 except Lactobacillus delbruckii bulgaricus 281, Bifidobacterium bifidum 232 and Bifidobacterium bifidum 235, which did not grow at pH 2.0. Lactobacillus fermentum 141 and Pediococcus acidolactici 252 was able to grow even at pH 1.5 also. All the 18 lactic acid bacterial strains showed a count (CFU/ml) in the range of 0.23x107 to 2.7x107 at pH 2.0 except Lactobacillus delbruckii bulgaricus 281, Bifidobacterium bifidum 232 and Bifidobacterium bifidum 235, which did not form detectable CFU/ml, whereas Lactobacillus helviticus 194 showed highest count of 2.7x107 CFU/ml at pH 2.0. Among all the Lactobacillus spp. Lactobacillus paraplantarum 321 and Lactobacillus paracasei 22 showed maximum growth at 0.3% oxgall concentrations similarly Bifidobacterium bifidum 233 and Bifidobacterium bifidum 236 showed maximum growth when compared to other bifidobacterial strains. Among eighteen Lactic acid bacterial strains Lactobacillus casei 17, Pediococcus acidolactici 252 (except Clindamycin), Lactobacillus delbruckii bulgaricus 281 (except for Nitrofurantoin, Clindamycin and Cefpodoxime) and Lactobacillus helviticus 194 (except for Gentamycin, Nitrofurantoin and Streptomycin) were resistant to all the antibiotics tested. Bifidobacterium bifidum 231 (except for Streptomycin and Kanamycin) and Bifidobacterium bifidum 236 (except Norfloxicin) showed resistance to all antibiotics tested. All these Lactic acid bacterial strains were screened for in vitro inhibition of pathogenic microorganisms namely Proteus vulgaris, E.coli ATCC, E.coli 448, Pseudomonas aeruginosa, Klebsialla pneumoneae, Salmonella typhimurium, Bacillus cereus, Salmonella para-B, Staphylococci aureus. All the eighteen strains showed good antibacterial activity against the tested pathogenic bacteria. The strains of Lactobacillus paraplantarum 321, Pedicocci acidolactici 252 and Lactobacillus bulgaricus 281 inhibited the growth of all pathogenic bacteria. Bifidobacterium bifidum 232 and Bifidobacterium bifidum 233 (except Bacillus cereus and Salmonella typhimurium) also inhibited the growth of all pathogens tested. All the eighteen Lactic acid bacterial strains showed growth at all the tested temperatures (15oC, 40oC, and 45oC) except Bifidobacterium bifidum 229, Lactobacillus fermentum 141 and Lactobacillus rhamnosus 18 which have shown growth only at the temperatures of 15oC and 40oC, except at 45oC Among twelve Lactobacillus spp. Lactobacillus helviticus 194 has shown the highest acidifying activity, whereas Lactobacillus casei 17 shown lowest acidifying activity. Similarly Bifidobacterium bifidum 231 shown highest acidifying activity, whereas Bifidobacterium bifidum 236 shown lowest acidification values when compared with the other Bifidobacterial strains. The present study identified functional probiotics for future in vivo studies to commercialize probiotic strains of lactic acid bacteria to promote public health.
Open Access
STUDY ON CHARACTERIZATION OF SLAUGHTERHOUSE WASTEWATER IN AND AROUND HYDERABAD CITY
(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2011-02) ENUMULA KUMAR; MADHAVA RAO, T(MAJOR); KRISHNAIAH, N; GOPALA REDDY, A; PRABU PRASADINI, P
ABSTRACT : The present study was undertaken to characterize the physical, chemical and microbiological properties of raw wastewater collected from three slaughterer houses located in and around Hyderabad city and to assess the efficiency of the treatment available at the plant and the effect of such wastewater on the environment. In raw wastewater from three slaughterhouses, the physical characteristics such as temperature of 31oC, pH of 6.8, turbidity in the range of 1847-4287 NTU, alkalinity varied between 433-903 mg/L, electrical conductivity in the range of 3.31-3.57 mS/cm, TDS varied between 1705-1896 mg/L, TSS ranged between 3001-5479 mg/L. The biochemical characteristics like DO varied between 0.41-1.45 mg/L, BOD ranged between 3559-4169 mg/L, COD varied between 4812-5308 mg/L, TOC varied between 2046-3345 mg/L, calcium ranged from 369 to 595 mg/L, NH4-N varied between 66-152 mg/L, nitrates in the range of 89-111 mg/L and phosphates of 76 mg/L were recorded. Major heavy metals such as lead, nickel and cadmium detected in wastewater from three slaughterhouses lead content ranged between 5.73 and 10.88 mg/L, nickel content of 1.03 mg/L and cadmium content varied from 0.59 to 1.47 mg/L detected. Except lead, cadmium and nickel values were below the effluent discharges limits recommended by pollution control board. In raw wastewater from three slaughterhouses, the microbiological characteristics such as TVC ranged from 68.21x106 - 105.14x 106 cfu/ml, total coliform count varied between 10.41 x106 - 35.16x106 cfu/ml recorded. The pathogens were isolated and the total count of Salmonella spp. ranged between 11.3-14.1x10 4 cfu/ml, Shigella count varied between 2.67x10 4-5.3x10 4 cfu/ml, S. faecalis count ranged between 8.58 x104 - 10.91x104 cfu/ml, S. aureus varied between 18.96x104 - 21.19x104 cfu/ml, B. cereus varied between 9.17 x104 - 10.19 x104 cfu/ml, and L. monocytogenes varied between 1900-6300 cfu/ml. The two slaughterhouses (i.e. II and III) have no treatment facilities and slaughterhouse I only having the UASB and DAF treatment facilities. The treated wastewater from slaughterhouse I has shown insufficient reduction in wastewater strength which was above the recommended limits for effluent discharges. The UASB reactor significantly reduced the wastewater strength. It has shown the removal rates of turbidity, TSS, BOD, COD, TOC, NH4-N, nitrates and phosphates as 71%, 80%, 79%, 71%, 63%, 70%, 53% and 42%, respectively. Whereas the DAF unit has shown the removal rates as 53%, 47%,42%, 55%, 48%, 36%, 49% and 77% respectively. The treatment of wastewater by UASB and DAF units has not been shown any effect on the levels of heavy metals. During UASB and DAF treatments the heavy metal followed an irregular trend with slight variation in levels. Further, the efficiency of UASB reactor has shown efficient removal rates for microbiological properties like TVC, TCC, total count of Salmonella spp., Shigella spp. S. faecalis, S. aureus, B .cereus and L. monocytogenes as 78%, 87.4%, 92%, 87%, 85%, 76%, 78% and 72% respectively, whereas the DAF unit has shown these removal rates as 82.6%, 85%, 64%, 70%, 72%, 58% and 72% respectively. The effect of the treated and raw wastewater from slaughterhouses on some physical and chemical properties of the soils was investigated. The results obtained revealed that both raw and treated slaughterhouse wastewater decreased the soil pH to 6.95 and to 6.88 from pH of 7.34 (control soil) and increased the electrical conductivity of soils to 1.59 mS/cm and to 1.48 mS/cm from 0.62 mS/cm (control soil). The raw and treated wastewaters also increased the organic carbon of control soils (1.75%) to 5.29% and to 6.24% and the available nitrogen of control soils (339.04 kg/ha) to 752.64 kg/ha and to 815.36 kg/ha. The heavy metal (Pb, Ni, and Cd) levels in soils polluted with raw and treated wastewaters are significantly increased to 4.11 mg/L, 0.38 mg/L and 0.54 mg/L when compared to that of control soils such as 11.4 mg/L, 0.05 mg/L and 0.13 mg/L, respectively.
Open Access
STUDIES ON THE INCIDENCE OF SHIGELLA IN LIVESTOCK PRODUCTS AND ENVIRONMENTAL SAMPLES
(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2010-07) DURGA RAMA DEVI, N; KRISHNAIAH, N(MAJOR); MADHAVA RAO, T; ANJANEYULU, Y
ABSTRACT: Out of 60 samples each of stools, drinking water, farm water, beef, chicken, egg and fish, Shigella spp. were found in 12 ,4, 15, 4, 3, 4, 3 and 5 respectively. Out of 12 positive stool samples for Shigella, 8 were S. flexneri, 3 were S. sonnei and 1 was S. dysenteriae. Out of 7 and 15 positive samples of drinking and farm water, S. flexneri was found in 4 and 10, S. sonnei 2 and 3 respectively and S. dysenteriae was one in each. Out of 4 positive samples each of beef and milk. S. flexneri was found in 3 and 2 S. sonnei one each and S. dysenteriae was 1 in milk and not found in beef. Out of 3, 3 and 5 positive samples of chicken, eggs and fish, S. flexneri was found in 2, 2 and 4 respectively. S. sonnei was found in one each and S. dysenteriae was not found. Out of 480 total different samples 53 were positive for Shigella spp., out of which 35 were S. flexeneri, 13 were S. sonnei and 4 were S. dysenteriae. For isolation and identification of Shigella spp., BHI broth enrichment was good for S. flexneri and SB broth was good for S. sonnei and S. dysenteriae. The isolation with or without enrichment and plating has shown that XLD and HEA media are superior over DCA, MAC and SS agar for S. flexneri and S. sonnei, where as for S. dysenteriae XLD, DCA, HEA and MAC has given moderate growth, with no growth on SS medium. In general, all the three enrichment broths have given better growth compared to direct plating. S. flexneri was highly sensitive to Kanamycin (94.28%) and Nalidixic acid (84.7%) and highly resistant to Gentamycin (97%) and Ampicillin (91.4%), where as S.sonnei was highly sensitive to Kanamycin (92.3%), Ampicillin (84.6%), Chloramphenical (69.23%) and highly resistant to Gentamycin (92.3%), Nalidixic acid (76.9%) and Cotrimaxozole (69.23%). S.dysenteriae was sensitive only to Kanamycin (75%) and Ciprofloxacin (25%) and resistant to Ampicillin, Gentamycin, Tetracycline , Nalidixic acid , Erythromycin, Chloramphenical and Cotrimoxazole (75%).
Open Access
DETECTION OF VIBRIO CHOLERAE IN FOODS BY PCR TECHNIQUE
(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2010-06) MAHESHWARI, MANI; KRISHNAIAH, N(MAJOR); MADHAVA RAO, T; ANJANEYULU, Y
ABSTRACT: The present study was undertaken to standardize PCR assay for detection of Vibrio cholerae, its serogroups (O1 and O139) and cholera toxin from foods and compare its efficacy with conventional cultural methods. Primers derived from ompW gene, rfbO1 and rfbO139 genes and ctxA gene were used which gave specific amplification products of 304, 192, 449, 302 bp for V.cholerae, its serogroups (O1 and O139) and cholera toxin respectively. To determine their suitability to PCR, four different template preparation methods viz. genomic DNA extraction, heat lysis, lysis buffers-1 and 2 were compared, of which heat lysis was found to be efficient and convenient. The specificity for V.cholerae, its serogroups (O1 and O139) and cholera toxin was tested using primers from ompW, rfbO1, rfbO139 and ctxA genes with V.cholerae and nine other non-V.cholerae strains, which gave specific products at 304, 192, 449 and 302 bp for V.cholerae, its serogroups and cholera toxin respectively. The minimum detection level was 2.5 cfu for V.cholerae, its serogroups and cholera toxin. Evaluation of two non-selective broths, i.e Luria Broth (LB) and Tryptic Soy Broth (TSB) and two selective broths, i.e Alkaline Peptone Water Broth (APW) and Salt Polymyxin Broth (SPB) for PCR compatibility, it was revealed that APW was superior followed by SPB, LB and TSB. Spiking studies were carried out by inoculating with pure culture of V.cholerae in selective enrichments broths (8h and 18h), which revealed that earliest detection time for V.cholerae by PCR was 18h and APW was the most suited selective broth for PCR assay. Screening of 245 naturally contaminated samples (35 each of water, fish, crab, shrimp, meat, milk and clinical stool samples) revealed 80 positive for V.cholerae (water-19, fish-16, crab-20, shrimp-6, meat-4, milk-3, and clinical stool samplres-12) out of which 45 belonged to O1 serogroup (water 11, fish-9, crab-12, shrimp-3, meat-2, milk-1 and clinical stool samples-7), 25 belonged to O139 (water-6, fish-5, crab-6, shrimp-2, meat-1, milk-1 and clinical stool samples-4). Out of 45 and 25 positive samples for O1 and O139, 35 and 20 were positive for cholera toxin respectively.

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