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2022 - 20236
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Subject: Veterinary Microbiology × End date: 2023 × Start date: 2020 ×
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Now showing 1 - 6 of 6
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    ThesisItemOpen Access
    Mapping the mutational events in the sheeppox and goatpox viruses by cultivation in the cell lines of heterologous host species origin
    (CSK HPKV, Palampur, 2023-05-28) Chandel, Swati; Chahota, Rajesh
    Sheeppox virus (SPPV) and Goatpox virus (GTPV) are highly contagious and host specific viruses but sometime cross infections may occur, which need further investigations. The present study was conducted to understand the genetic adaptation or mutations undergoing in the SPPV and GTPV, while growing in a homologous and heterologous host cell systems. Primary cell culture of kid testicular (KT) and lamb testicular (LT) cells were prepared and used for serially passaging (n=15) SPPV strain SP3 and GTPV strain SP5. Different cytopathic effects were observed on 3rd, 5th and 7th day post inoculation. Scoring was given based on the percentage of cells affected. Non-parametric one-way analysis of variance (ANOVA) showed that both SPPV and GTPV have significantly higher infectivity in LT cell line as compared to KT cell line. Mutational events mapping on the whole genome sequences of SP3 and SP5, passaged on KT cells showed 65 variations in SP3/SKT-P15 and 129 in SP5/GKT-P15. Total 61 indels in SP3/SKT-P15 and 114 in SP5/GKT-P15 and 4 SNVs in SP3/SKT-P15 and 15 SNVs in SP5/GKT P15 were also observed. The terminal regions containing host range and virulence genes showed more mutational events i.e, 67.44% mutations in SP5/GKT-P15 and 56.92% mutations in SP3/SKT-P15. Some genes were found to have comparatively more mutations e.g. ANK gene showed the maximum 7 mutations, followed by late transcription factor VLTF-4 gene (n=6) and superoxide dismutase gene (n=5) in SP5/GKT-P15, while in SP3/SKT-P15, 3 mutations were detected in ER-localized apoptosis regulator gene and EEV maturation gene. This may be indicating their predominant roles in viral replication/adaptation under in-vitro growth conditions. Some genes like EEVg, which was found mutated after serial passaging in heterologous cell types only, along with altered phenotypes (extensive cell aggregation), may be required for long term spread and survival of the virus. This study showed different mutational trends in SPPV and GTPV, while growing in homologous and heterologous cell types. Different genes showed varied degrees of mutations indicating their pivotal role in replications under altered conditions. To confirm the biological roles played by these mutations to the advantage or disadvantage of the virus, while growing in different cell type/host, further experiments are required.
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    ThesisItemOpen Access
    Phenotypic and genotypic characterization of Staphylococcus aureus of animal origin
    (CSK HPKV, Palampur, 2023-01-24) Barsain, Shivani; Verma, Subhash
    Staphylococcus aureus is an opportunistic pathogen of humans and animals causing both acute and chronic infections. Several virulence-related factors have been described in S. aureus with multiple roles in attachment, multiplication, invasion, and evasion of host immune responses. The disease outcome therefore, does not merely depend on the host’s immune status but also on S. aureus phenotypic and genotypic virulence-associated factors. Several strains of S. aureus are being recovered from livestock suffering from various diseases; however, their true virulence potential and antibiotic resistance status never become known. This poses a huge challenge to veterinarians, owners and, the livestock industry because of losses associated with such isolates, their transmission and subsequent animal and human infections. Under this study, a total of 50 isolates of livestock origin were genotypically and phenotypically characterized. All isolates were nuc and catalase positive. Most of the isolates exhibited coagulase, biofilms, and hemolysins production. The mecA was detected in 38% of isolates; lukpv in 76%, tsst in 2%, sdrD in 80%, sdrE in 58%, clfA in 78%, cna in 34%, CC398 in 56% isolates. No isolate was positive for sea, scn, sak, vanA and icaA. The S. aureus were tested for their susceptibility to cloxacillin, amoxicillin, cephalexin, neomycin, tobramycin, doxycycline, erythromycin, vancomycin, enrofloxacin and levofloxacin. Only 12% isolates were susceptible to all the tested antibiotics; whereas 78% were resistant to one or more antibiotics. The isolates revealed 100% susceptibility to levofloxacin and enrofloxacin followed by vancomycin (98%), cephalexin (96%), erythromycin (94%), doxycycline (94%), neomycin (94%), tobramycin (84%), cloxacillin (70%), amoxicillin (46%). Amoxicillin was the least effective drug. About 16% isolates also exhibited MDR involving amoxicillin, erythromycin, doxycycline, tobramycin and cephalexin. A MAR index > 0.2 was recorded in 26% of isolates. Out of 50 isolates, 30% belonged to the highly virulent class, 54 % to the medium and 16% to low virulent class, respectively. This study confirmed that these isolates were livestock adapted and majority of them belonged to a single lineage comprising of CC398 cluster. In vivo pathogenic potential of isolates will allow S. aureus better classification enabling epidemiological tools in the hands of researchers and clinicians for better outcomes.
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    ThesisItemOpen Access
    Immunogenetic and biochemical profiling of Gaddi dogs
    (CSK HPKV, Palampur, 2023-01-24) Yadav, Priyanka; Sharma, Mandeep
    Gaddi dog is a generic term deriving its name from the nomadic shepherds referred to as Gaddis tribe (parts of Himachal Pradesh, Uttarakhand, J&K); who rear these dogs primarily to protect and guard their sheep and goats. It is a matter of great concern that this important germplasm is unknown to the masses and not recognized by any Kennel Club of India. This unique canine germplasm, therefore, needs to be documented and registered. The present study was designed to study the blood and haematological profiles; and parameters related to the innate immunity of Gaddi dogs that may help in the characterisation and registration of these dogs to a defined breed. The average physiological values for rectal temperature (101.4 ± 0.2 °F), respiratory rate (25.6 ± 0.60 breaths per min.), and heart rate (127.3 ± 1.20 beats per minute) were recorded. The values recorded for haematology and biochemical parameters from seven Gaddi dogs were within the normal range as has been reported for dogs of some other breeds. The mean percent values of major lymphocyte subsets were 44.50, 25.03, and 10.30 for T-helper cells (CD4+), cytotoxic T cells (CD8+) and B lymphocytes (CD21+), respectively. The respiratory burst activity of PMNCs (neutrophils) as measured by Nitroblue tetrazolium test and the DCFH-DA probe-based assay revealed around two-fold increase. Ferric reducing the ability of plasma assay showed higher FRAP values for Gaddi dogs (0.183-0.234 Fe2+ µmoles per ml) when compared with diseased dogs (0.172-0.201 Fe2+ µmoles per ml) of other breeds. The complement haemolytic activity (CH50) of Gaddi dogs was found to be in the range of (19-50.9 CH50 units) and the mean was 27.2 CH50 units. These values for dogs of some other breeds were in the range of 22.7-37.8 CH50 units. The expressions and sequences variation of two major antimicrobial peptides, CBD-103 and K9CATH were also studied. The expression of both CBD-103 and K9CATH were noticed in blood, oral and nasal mucosa. A 3-base pair deletion resulting in the loss of Glycine at position 23 of CBD-103 has been associated with black coat colour in certain breeds of dogs. The result of this study found that the coat colour in studied Gaddi dogs was independent of G23 deletion in CBD-103 and it was not associated with black coat colour in these dogs. This study also reported multiple alleles of K9CATH in Gaddi dogs.
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    ThesisItemOpen Access
    Microbiological studies on reproductive disorders of canines
    (Palampur, 2022-12-03) Lali, Kasturi; Dhar, Prasenjit
    For centuries, dogs have been considered to be man’s best friend. Diseases related to reproductive tract are quite common in canine practice. The present study was carried out with the objective to find out the association of different microbes in reproductive disorders of canines and determination of the antimicrobial susceptibility profile of the isolated microbes. Additionally, the bacterial enumeration of the obtained samples and minimum inhibitory concentration of the antimicrobials were also determined. Molecular detection of Brucella spp. was done employing PCR. A total number of 102 samples were collected from different places of Himachal Pradesh. These were accrued from dogs [both males (11) and females (91)] suffering from any reproductive disorders (purulent vaginitis, pyometra, dystocia, abortion, orchitis, etc.) as well as from apparently healthy dogs. The samples included vaginal swabs, uterine discharge, aborted foetus, preputial swabs and washings. The most frequently recorded reproductive disorder was of purulent vaginitis (15/102; 14.71 per cent) followed by pyometra (11/102;10.78 per cent). The age group of 2-5 years were mostly affected (46.07 per cent). A total of 124 isolates were recovered from 102 samples of which 112 (90.32 per cent) were bacterial isolates and 12 (9.68 per cent) were fungal isolates. The most prevalent bacteria obtained was E.coli (21.77 per cent) followed by Staphylococcus spp. (15.32 per cent) and Pseudomonas spp. (7.3%) while the most commonly isolated yeast was Candida spp. (4.84 per cent). The antimicrobial susceptibility profile of the recovered bacterial isolates revealed enrofloxacin (94.49 per cent) to be the most effective drug while fluconazole (100 per cent) was recorded as the most effective antimycotic agent. Bacterial enumeration revealed significant difference in the number of bacteria (cfu/ml) in diseased dogs in comparison to apparently healthy dogs which makes the quantitative analysis reliable. The obtained MIC value of different antimicrobials showed correlation with their resistance pattern in the AMST. 13 out of 102 samples (12.7 per cent) were positive for the genus Brucella (bcsp31) through PCR, however no isolates were obtained through standard procedures of isolation.. In conclusion, the study recorded plethora of microbial species associated with various reproductive disorders in canines along with their antimicrobial patterns.
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    ThesisItemOpen Access
    Molecular characterization and plasmid profiling of Pasteurella multocida of animal origin
    (palampur, 2022-06-04) Parkhe, Prapti; Verma, Subhash
    Pasteurella multocida, is a Gram negative opportunistic bacterial pathogen capable of causing several economically important diseases in animals including zoonosis. There are multiple capsular, LPS and virulence genotypes of this organism which are differently associated with various diseases in different hosts. In this study, a total of 75 isolates from different animal host species were studied for their capsule and lipopolysaccharide (LPS) genotypes, virulence-associated genes, antimicrobial susceptibility pattern and plasmid profile. A capsular type B was predominant genotype and its prevalence was recorded 85.3% in bovine, 40% in ovine, 66.7% in porcine and 20.8% in poultry isolates. The percent prevalence of capsular type A was 79.2 in avian followed by 40 in ovine, 33.3 in porcine and 12.2 in bovine isolates. Both rabbit and deer isolates were detected as capsular type A and only one isolate each from bovine and ovine belonged to capsular type D. The isolates were assigned to seven groups based on both capsule and LPS genotype, namely A:L1 (13/29), A:L3 (2/29), A:L6 (6/29), A:non-typeable (8/29), B:L2 (42/44), B:non-typeable (2/41) and D:L3 (2/2). When combining both the typing systems, L1 (44.8%), L2 (95.4%) and L3 (100%) were the most prevalent LPS genotypes found in capsular type A, B and D, respectively. P. multocida displayed significant association of a given capsule type with a particular LPS genotype. Many P. multocida remained untypeable for their LPS genotypes which suggested presence of genomic diversity in primer binding locations of LPS biosynthesis loci. Of the total 12 virulence genes, three (ompH, sodC, and ptfA) showed high prevalence in all capsular types whereas toxA was not detected in any of the genotypes. A large proportion of virulent genes (75 to 100%) were present in non-typeable strains. A given P. multocida genotype with a specific set of virulence associated genes clustered together suggesting a genetic relatedness despite their place of origin. Majority of isolates were susceptible to most antibiotics, however, resistance to tetracyclines, streptomycin and sulfonamides were displayed by 62%, 26% and 24% of isolates. Most MDR isolates belonged to capsular type B (15/17, 88.2%) and the MAR indices ranged from 0.04 to 0.39. Only a single isolate harboured a plasmid of molecular size around 11.6 kb, suggesting rarity of plasmids in studied isolates. Additional studies would be needed to understand completely the role of P. multocida genotypic combinations in disease outcome in different hosts and for their exploration as vaccine candidates. The detailed sequence analysis would provide more insight about various characteristics of the plasmid.
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    ThesisItemOpen Access
    Molecular characterization and plasmid profiling of Pasteurella multocida of animal origin
    (palampur, 2022-03-31) Parkhe, Prapti; Verma, Subhash
    Pasteurella multocida, is a Gram negative opportunistic bacterial pathogen capable of causing several economically important diseases in animals including zoonosis. There are multiple capsular, LPS and virulence genotypes of this organism which are differently associated with various diseases in different hosts. In this study, a total of 75 isolates from different animal host species were studied for their capsule and lipopolysaccharide (LPS) genotypes, virulence-associated genes, antimicrobial susceptibility pattern and plasmid profile. A capsular type B was predominant genotype and its prevalence was recorded 85.3% in bovine, 40% in ovine, 66.7% in porcine and 20.8% in poultry isolates. The percent prevalence of capsular type A was 79.2 in avian followed by 40 in ovine, 33.3 in porcine and 12.2 in bovine isolates. Both rabbit and deer isolates were detected as capsular type A and only one isolate each from bovine and ovine belonged to capsular type D. The isolates were assigned to seven groups based on both capsule and LPS genotype, namely A:L1 (13/29), A:L3 (2/29), A:L6 (6/29), A:non-typeable (8/29), B:L2 (42/44), B:non-typeable (2/41) and D:L3 (2/2). When combining both the typing systems, L1 (44.8%), L2 (95.4%) and L3 (100%) were the most prevalent LPS genotypes found in capsular type A, B and D, respectively. P. multocida displayed significant association of a given capsule type with a particular LPS genotype. Many P. multocida remained untypeable for their LPS genotypes which suggested presence of genomic diversity in primer binding locations of LPS biosynthesis loci. Of the total 12 virulence genes, three (ompH, sodC, and ptfA) showed high prevalence in all capsular types whereas toxA was not detected in any of the genotypes. A large proportion of virulent genes (75 to 100%) were present in non-typeable strains. A given P. multocida genotype with a specific set of virulence associated genes clustered together suggesting a genetic relatedness despite their place of origin. Majority of isolates were susceptible to most antibiotics, however, resistance to tetracyclines, streptomycin and sulfonamides were displayed by 62%, 26% and 24% of isolates. Most MDR isolates belonged to capsular type B (15/17, 88.2%) and the MAR indices ranged from 0.04 to 0.39. Only a single isolate harboured a plasmid of molecular size around 11.6 kb, suggesting rarity of plasmids in studied isolates. Additional studies would be needed to understand completely the role of P. multocida genotypic combinations in disease outcome in different hosts and for their exploration as vaccine candidates. The detailed sequence analysis would provide more insight about various characteristics of the plasmid