OCCURRENCE AND MOLECULAR CHARACTERISATION OF CAMPYLOBACTER SPP. IN SEAFOODS AND ASSOCIATED ENVIRONMENT OF KERALA AND CONTROL OF BIOFILM FORMATION

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dc.contributor.advisorB. Sunil
dc.contributor.authorDEEPA JOLLY
dc.date.accessioned2023-02-16T11:28:27Z
dc.date.available2023-02-16T11:28:27Z
dc.date.issued2021-07-29
dc.descriptionSubmitted in partial fulfilment of the requirement for the degree of Doctor of Philosophy in Veterinary Public Healthen_US
dc.description.abstractDistribution of Campylobacter spp. in seafoods of fish catchment areas (Vizhinjam, Neendakara, Munambam, Chavakkad and Puthiyappa) and it’s related environment in Kerala and the presence of the organism in humans in central Kerala, were determined over a period of two years. A total of 2179 samples from fish catchment areas from the coastal districts, fresh-water bodies and it’s related areas and human stool samples were subjected to conventional culture technique and molecular characterization. Molecular characterization was performed by mPCR, targeting the presence of genus-specific 16S rRNA, C. jejuni specific mapA, C. coli specific ceuE genes and the virulence gene cadF. Of the overall 250 positive samples, 44.4 per cent expressed cadF, a virulence gene. Among the seafoods, 12.24 per cent of 245 fresh marine fish, 11.76 per cent of 170 crustaceans, 13.51 per cent of 185 molluscs from the five fish catchment areas were positive for Campylobacter spp. Presence of the organism in freshwater samples was observed in 21.4 per cent of 70 fishes, 12.1 per cent of 66 crustaceans, and was absent in molluscs. In freshwater bodies, the occurrence ranged between 6.67- 54.76 per cent, the highest being from rivers/streams, while 6.67 per cent of seawater from the coastal area revealed it’s presence. Prevalence in humans was found to be 12.38 per cent. The organism could be detected from the fish baskets, landing floor, water from boat tank and handwash of the handlers from many areas. On correlating the presence of the organism with the physicochemical parameters of water, the organism was more likely to be present in alkaline waters of lakes, while it’s presence was negatively correlated with turbidity of rivers/streams and hardness of pondwater. Phenotypic antibiotic resistance of 62 campylobacter isolates from multiple sources against 36 antibiotics revealed a higher resistance of the 39 C. jejuni isolates against cefotaxime (94.87 per cent), aztreonam (87.18 per cent), ampicillin (84.62 per cent), cefuroxime (74.36 per cent), while sensitivity towards doripenum, gatifloxacin and amikacin was observed for 92.31, 87.18 and 76.92 per cent of the isolates, respectively. Genotypic resistance revealed that only 11.29 per cent, 38.71 per cent and 14.52 per cent of the isolates that were phenotypically resistant to the corresponding antibiotics, showed the presence of aph-3-1, blaOXA-61 and tet(O), cmeB genes, respectively. The multidrug resistance of the 39 C. jejuni isolates was 97.44 per cent, whereas that of 23 C. coli isolates was 86 per cent. Multiple antimicrobial resistance (MAR) index of the isolates was within the range of 0.06-0.89. Survivability studies of Campylobacter spp. (C. jejuni NCTC 11168 and C. coli isolate) was conducted in sea-water and river-water samples, at two incubation temperatures, in autoclaved and nonautoclaved water. Statistical analysis revealed considerable differences in the survivability of the organism at different storage periods and temperature. Maximum period of survival of C. jejuni NCTC 11168 at 25°C was 14 days in nonautoclaved sea-water and for C. coli, in autoclaved sea-water was upto 60 days. In river-water at 4°C it was 60 days under autoclaved conditions and at 25°C, it was 90 days in nonautoclaved water. The corresponding values for C. coli at 4°C was 120 days for both autoclaved and nonautoclaved water, and at 25°C it was 150 days for autoclaved water. Survival characteristics of the organism points to the degree of adaptability of the organism under varied environmental conditions. Biofilm formation of the two strains on abiotic surfaces like stainless steel, fibre and aluminium were studied, in which the maximum biofilm formation was seen in fibre. Sanitisers were effective against the C. jejuni/C. coli at various combination treatments. Hot water (75°C for 5 min/65°C for 3 min), bleaching powder (200 ppm), chitosan (1.5 per cent for 3 min) as well as aqueous extract (1.00 per cent for 5 min/ 2.00 per cent for 5 min) of Eichhornia crassipes (water hyacinth) on biofilms of C. jejuni NCTC 11168 and C. coli on the various surfaces were effective in eliminating the organism. Field Emission Scanning Electron Microscopical structure of the biofilms on the various surfaces before and after treatment were also observed. This study unravelled the overall prevalence of Campylobacter spp. in the state especially in the fish catchment areas and associated water bodies, which in turn would be helpful in improving the awareness on food safety among fisher-folk, consumers and the state regulatory authorities.en_US
dc.identifier.urihttps://krishikosh.egranth.ac.in/handle/1/5810193942
dc.keywordsCAMPYLOBACTER SPP., SEAFOODS AND ASSOCIATED ENVIRONMENT , BIOFILM FORMATION , CONTROL OF BIOFILM FORMATION, Occurrence of Campylobacter spp. in seafoods and various related matrices, Isolation and identification of Campylobacter spp., Antibiotic resistance profile , Survivability in water, Biofilm formation of Campylobacter spp. in food industry, Detection of virulence gene by Polymerase Chain Reaction, Nucleotide sequence analysis, Antibiotic resistance profiling , Biofilm formation of Campylobacter spp. on abiotic surfaces , Eichhornia crassipes extract, Control of Campylobacter biofilm, Survivability of Campylobacter jejuni NCTC 11168 in sea and river-water, Detection of physico-chemical characteristics of water, Detection of physicochemical characteristics of soil,en_US
dc.language.isoEnglishen_US
dc.pages341 p.en_US
dc.publisherCOLLEGE OF VETERINARY AND ANIMAL SCIENCES MANNUTHY, THRISSURen_US
dc.research.problemDetection of Campylobacter spp. in fishes, shellfishes, environmental sources and stool samples, Isolation of Campylobacter spp. by conventional method and confirmation of the isolates by Polymerase chain reaction (PCR) , Identification of the genes encoding virulence and antibiotic resistance , Antibiogram of Campylobacter isolates , Assessment of survivability of Campylobacter jejuni in seawater and freshwater at 4°C and 25°C , Evaluation of biofilm forming ability of the isolates and effect of sanitisers on the biofilmen_US
dc.subVeterinary Public Healthen_US
dc.themeCAMPYLOBACTER SPP. IN SEAFOODS AND ASSOCIATED ENVIRONMENT OF KERALA AND CONTROL OF BIOFILM FORMATIONen_US
dc.these.typePh.Den_US
dc.titleOCCURRENCE AND MOLECULAR CHARACTERISATION OF CAMPYLOBACTER SPP. IN SEAFOODS AND ASSOCIATED ENVIRONMENT OF KERALA AND CONTROL OF BIOFILM FORMATIONen_US
dc.typeThesisen_US
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