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20225
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Subject: Dairy Microbiology × End date: 2022 × Start date: 2022 ×
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    ThesisItemOpen Access
    ASSESSMENT OF ANTIMICROBIAL RESISTANCE IN Escherichia coli AND SALMONELLA ISOLATED FROM INTEGRATED BROILER CHICKEN FARMS
    (KARNATAKA VETERINARY, ANIMAL AND FISHERIES SCIENCES UNIVERSITY, BIDAR, 2022) i ASSESSMENT OF ANTIMICROBIAL RESISTANCE IN Escherichia coli AND SALMONELLA ISOLATED FROM INTEGRATED BROILER CHICKEN FARMS ADDAKAL ANANDRAJ HANNAH JOANNAS; SHARADA. R)
    A study was conducted to identify the driving factor of AMR by monitoring the phenotypic and genotypic AMR of E. coli and Salmonella isolated from 3 broiler farms (2 integrated and 1 associated). In all, 101 samples were collected at different sampling points in one entire crop cycle. The overall presence of E. coli and Salmonella was 76.23 and 9.09 per cent. Farm 1 samples did not yield Salmonella. Antimicrobial resistance based on disc diffusion assay and MIC revealed that all E. coli and Salmonella isolates were resistant to at least one antibiotic. E. coli and Salmonella showed highest resistance to ampicillin and doxycycline (92 and 87%), followed by enrofloxacin, gentamicin, trimethoprim sulphamethoxazole, amikacin and colistin and lesser resistance to ceftiofur. All the isolates were further screened for the presence of 22 AMR genes belonging to three groups of antibiotics by PCR. Among the AMR genes, highest presence was recorded for qnrB(96.87%), qepA(92.7%) followed by blaTEM(71.96%), blaCTX-M universal(29.56%), qnrS (28.93%), qnrD (28.62%), blaCTX-Mgroup1 (10.8%), mcr3 (6.27%), blaCTX-M group2 (5.64%), oqxAB (5.5%), blaSHV (4%), blaOXA (2.5%), blaCTX-M group 8/25 (1.85%), aac(6’)-Ib-cr (1.5%) and qnrA (0.5%) in E. coli. In Salmonella, blaTEM and blaSHV (100%) followed by qnrD (68.3%), qnrB (61.6%), qnrA (15%) and oqxAB (5%) in Salmonella. Maximum AMR genes in E. coli and Salmonella were found in boot socks, ileal and cecal contents and fecal swabs. Thus, these may be the driving factors for AMR. Also, on day zero high prevalance of AMR genes was found. A significant correlation was observed between phenotypic and genotypic AMR of β Lactams and quinolones but not for colistin. No significant difference was observed in the overall AMR pattern between integrated and associated farms. The findings calls for the need of efficient monitoring and institution of control strategies for effective mitigation of AMR in all the three broiler farms.
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    ThesisItemOpen Access
    EFFECT OF NATAMYCIN ON THE MICROBIOLOGICAL QUALITY OF PANEER
    (KARNATAKA VETERINARY, ANIMAL AND FISHERIES SCIENCES UNIVERSITY, BIDAR-585 401, 2022) K. SREERAMYA; RAMACHANDRA, B.
    The present study was aimed in increasing the shelf life of paneer by the antifungal agent natamycin. The counts in fresh paneer ranged from 1.00 to 4.20 and in stored paneer the count was from 1.00 to 2.14 log10cfu/g. All the yeast isolates (5 no.) were identified to Rhodotorula sp. and molds isolates were identified as Aspergillus (1 no.), Mucor (1 no.), Penicillium (1 no.) and Rhizopus (2 no.) at 50 ppm natamycin. Rhodotorula sp. produced inhibitory area of 668.03 sq.mm whereas, the molds Aspergillus, Mucor, Rhizopus and Penicillium produced 138.16, 452.16, 668.03 and 452.16 sq.mm. The yeast and molds counts at 20, 30, 40 and 50 ppm incorporated paneer were 4.22, 4.00, 4.10, 3.95 and 3.70 log10cfu/g. Among the dipping, swabbing and spiking the dipping method was found effective in complete inhibition of yeast and molds at 1500 ppm natamycin in both the fresh and stored paneer. The scores given by the judges found that no significant changes in the sensory parameters of the control and natamycin treated samples of both fresh and stored paneer. Then the optimized natamycin treated paneer samples at 1500 ppm by dipping were subjected for sensory, chemical and microbiological analysis during storage at refrigeration temperature (5 ℃). Based on the analysis of moisture, water activity, acidity, FFA, TBC, coliforms, proteolytic, lipolytic and yeast and molds counts the shelf life of fresh and stored paneer were declared. Based on the appearance of yeast and molds the shelf life of fresh and stored natamycin treated paneer at refrigeration temperature were 20 days and 30 days respectively.
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    ThesisItemOpen Access
    CHARACTERIZATION OF DAIRY ORIGIN PROBIOTIC BACILLUS SPECIES
    (KARNATAKA VETERINARY, ANIMAL AND FISHERIES SCIENCES UNIVERSITY, BIDAR-585 401, 2022) K. SIREESHA; PRABHA. R
    In the present study, dung sample obtained from KVAFSU dairy farm showed high bacterial, aerobic spore, acid tolerant spore counts of 8.42, 5.42 and 3.4 log10cfu/g, respectively. Fodder of the dairy farm had high bile tolerant spore count of 4.71 log10 cfu/g while Soil, feed, fodder, dung, silage, udder swab, hand swab, pail rinse, can rinse, water, aseptic milk, pail milk, can milk, pasteurized milk and air samples revealed lower counts of aerobic spore, acid and bile tolerant sores. According to specific tests, among 19 Bacillus isolates, 16 isolates were identified as Bacillus licheniformis and one each as B. coagulans, B. subtilis and B. tropicus. Among 19 isolates, B7 and B12 exhibited higher per cents of survivability with respect to acid accounting for 96.20, 99.52 and bile of 99.32 and 98.57, respectively. The hydrophobic nature in xylene of B7 and B12 were 37.7 and 38.7%, respectively. B7 and B12 were genotypically identified as B. subtilis and B. tropicus. B7 and B12 Bacillus strains gave promising growth in urad dhal medium compared to cheese whey. B7 and B12 gave promising growth on urad dhal B7 and B12 were inoculated into sterile urad dhal medium (1 part dhal + 0.7part water + 0.2part tomato juice + 0.1part skim milk powder), fermented at 37°C for 48 h, dried at 35 °C for 20 h, powdered and packed in pouches and kept for shelf-life study at 25°C and 5°C temperatures. At the end of 49th day of storage at 25°C, the count of B7 and B12 were 6.16 and 6.24 log 10 cfu/g from initial counts of 9.73 and 9.82 log 10 cfu/g on 0 day. B7 and B12 at 75th day of storage at 5°C maintained viable count 6.53 log10cfu/g with initial counts of 9.73 and 9.82 log 10 cfu/g, indicating direct use of powder to increase probiotics in gut of human beings.
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    ThesisItemOpen Access
    STUDY ON THE EFFECT OF ANTIMICROBIAL RESISTANT PATHOGENS OF BOVINE MASTITIS AND LACTIC ACID BACTERIA IN DAHI
    (KARNATAKA VETERINARY, ANIMAL AND FISHERIES SCIENCES UNIVERSITY, BIDAR-585 401, 2022) GANESH; PRABHA. R
    In the present study 45 isolates of bovine mastitis were obtained from Veterinary Microbiology Department, KVAFSU, Bengaluru. The purified 40 Gram-positive isolates and 5 of Gram negative, were identified as Streptococcus uberis (10), Streptococcus agalactiae (12); one each of Staphylococcus delphini, Staphylococcus carnosus and Staphylococcus gallanarium while 6 each of Staphylococcus equorum & Staphylococcus epidermis and 3 Staphylococcus aureus. Gram negative 5 isolates were identified as E. coli (3), Salmonella enterica (1) and Alcaligenes sp. (1). All the isolates when subjected to antibiotic susceptibility test (18 antibiotics), Streptococcus agalactiae M36, Staphylococcus aureus M35, E. coli M33, Salmonella enterica M27 showed highest resistance for 16, 15, 7, 5 antibiotics, respectively. The highest antibiotic resistant isolates were PCR analysed for their speciation. Lactococcus lactic ssp. lactis 1, Lactococcus lactic ssp. lactis 2, Lactococcus lactic ssp. cremoris were used in dahi preparation alone or in combination along with selected mastitic causing bacteria having public health significance and highly resistant to antibiotics. The prepared dahi had viable count of around 8.6 both in individual and in mixed lactic cultures with lactic acid content of 0.77%. Lactic cultures exhibited resistance to ampicillin, azithromycin, cefoperazone, ceftriaxone, nalidixic acid, penicillin, rifampicin and vancomycin. Mastitic bacterial isolates, showed resistant to all the antibiotics, while the Streptococcus agalactiae and E. coli showed susceptibility to streptomycin. In dahi prepared using mixed lactic culture, there may be possibility of transfer of resistant factor of ceftriaxone to Salmonella enterica ssp. enterica M27 and both ceftriaxone and ofloxacin resistance to Staphylococcus aureus M35 from lactic cultures which were resistant in dahi while pathogens in broth were susceptible.
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    ThesisItemOpen Access
    PRODUCTION OF ENCAPSULATED PROBIOTIC BACTERIAL CONCENTRATES AND THEIR PERFORMANCE IN YOGHURT
    (KARNATAKA VETERINARY, ANIMAL AND FISHERIES SCIENCES UNIVERSITY, BIDAR-585 40, 2022) BAINDLA BHARGAVI; RAMACHANDRA, B.
    The probiotic cultures, Lactobacillus acidophilus and Bifidobacterium bifidum cells were concentrated by centrifugation process obtained viable count of 10.26 and 10.14. In the present study, 3 % sodium alginate and 0.3 M calcium chloride had considered optimum because of its soft textured beads and the diameter of Lactobacillus acidophilus and Bifidobacterium bifidum were 971 and 941 μm. The 2 % of Lactobacillus acidophilus and Bifidobacterium bifidum in 3 % sodium alginate got higher encapsulation efficiency of 97.1 and 96.4 %. The encapsulated Lactobacillus acidophilus and Bifidobacterium bifidum subjected to acid tolerance test at pH 1.5 and pH 3.0 for 2 h and bile tolerance (0.3 % ox bile) for 6 h resulted in higher survival rate (%) of 72.8, 75.0, 99.2 and 74.8, 79.4, 99.3 than free cells 32.2, 51.1, 83.6 and 39.8, 48.8, 89.6. The yoghurt prepared with combination of 3 per cent of encapsulated Lactobacillus acidophilus and Bifidobacterium bifidum had highest overall acceptability of 8.23. Addition of encapsulated probiotic bacteria reduced acid development in yoghurt compared to free cells and control during storage. The results showed that there was an increase in survival by 1 log cell numbers of encapsulated Lactobacillus acidophilus and Bifidobacterium bifidum in yoghurt during storage. This study revealed that incorporation encapsulated probiotic bacteria do not substantially alter the overall sensory characteristics of yoghurt and microencapsulation helps to retain the viable count of probiotic bacteria (106 log cfu/g) in yoghurt after 30 days of storage at refrigeration temperature (5 ℃).