Anju P. Kunjadia

Identification and Antibiogram of Microbes Associated with Bovine Mastitis

An investigation of Mastitis in cattle was carried out in Anand city and in nearby villages of Gujarat state using California Mastitis Test (CMT) kit. The prevalence of clinical and subclinical mastitis was found to be 5.5% and 15.75%, respectively. Staphylococcus aureus was identified through strain specific polymerase chain reaction; the remaining isolates identified on the basis of molecular analysis by 16S rDNA sequencing and phylogenetic analysis were Staphylococcus species, B. pumilus, Staphylococcus chromogenes, Bacillus species, and Pseudomonas species. In vitro antimicrobial susceptibility pattern of all the isolates was checked against 13 different antibiotics using the agar disc diffusion method. Highest bacterial resistance was observed with penicillin G and oxacillin antibiotics. It was also observed that the patterns of bacterial resistance have not changed in India over the years. The data supports the decrease in the incidence of mastitis but the rate of decrease is minimal. More effective control strategies are required.

Evaluation of a topical herbal drug for its in-vivo immunomodulatory effect on cytokines production and antibacterial activity in bovine subclinical mastitis

Background: Antibiotics have been in use in the treatment of bovine mastitis since decades; however, their use is associated with cost issues and human health concern. Use of herbal drugs does not generally carry these disadvantages. Many plants/herbs have been evaluated in the treatment of bovine mastitis with additional property of immunomodulation in affected mammary gland. Aim: To evaluate a topical herbal drug in two breeds of cattle for its in-vivo immunomodulatory effect on cytokines production and antibacterial activity in bovine subclinical mastitis. Materials and Methods: The response to treatment was evaluated by enumerating somatic cell count (SCC), determining total bacterial load, and studying the expression of different cytokines (interleukin [IL]-6, IL-8, IL-12, granulocyte macrophage-colony stimulating factor, interferon (IFN)-γ and tumor necrosis factor [TNF]-α). Results: The pre- and post-treatment SCC in mastitic quarters statistically did not differ significantly, however, total bacterial load declined significantly from day 0 onwards in both the breeds. Highly significant differences (P < 0.01) were observed in all the cytokines on day 0, 5, and 21 postlast treatment in both the breeds. The expression level of all the cytokines showed a significant increase on day 5, while a decrease was noticed on day 21 in both the breeds of cattle. The comparison of cytokine expression profiles between crossbred and Gir cattle revealed a significant difference in expression of IL-6 and TNF-α. However, other cytokines exhibited a similar pattern of expression in both breeds, which was non-significant. Conclusion: The topical herbal drug exhibited antibacterial and immunomodulatory activities in subclinical mastitis and thus the work supports its use as alternative herbal therapy against subclinical udder infection in bovines.

RNA-Seq reveals the molecular mechanism of trapping and killing of root-knot nematodes by nematode-trapping fungi

Nematode-trapping fungi are well known for their inherent potential to trap and kill nematodes using specialized trapping devices. However, the molecular mechanisms underlying the trapping and subsequent processes are still unclear. Therefore, in this study, we examined differential genes expression in two nematode-trapping fungi after baiting with nematode extracts. In Arthrobotrys conoides, 809 transcripts associated with diverse functions such as signal transduction, morphogenesis, stress response and peroxisomal proteins, proteases, chitinases and genes involved in the host-pathogen interaction showed differential expression with fold change (>±1.5 fold) in the presence of nematode extract with FDR (p-value < 0.001). G-proteins and mitogen activated protein kinases are considered crucial for signal transduction mechanism. Results of qRT-PCR of 20 genes further validated the sequencing data. Further, variations in gene expression among Duddingtonia flagrans and A. conoides showed septicity of nematode-trapping fungi for its host. The findings illustrate the molecular mechanism of fungal parasitism in A. conoides which may be helpful in developing a potential biocontrol agent against parasitic nematodes.

Analysis of Virulence Associated and Antibiotic Resistance Genes of Microbes in Subclinical Mastitis Affected Cattle Milk by Pyrosequencing Approach

Analysis of Virulence Associated and Antibiotic Resistance Genes of Microbes in Subclinical Mastitis Affected Cattle Milk by Pyrosequencing Approach Metagenomic analysis of milk samples collected from Gir, Kankrej (Bos indicus) and crossbred (Bos taurus X Bos indicus) cattle harbouring subclinical mastitis was carried out by pyrosequencing technology to elucidate virulence associated genes and sequences from the microbial community. Metabolic profile by a web-based tool MG-RAST revealed that members of Virulence, disease and defense associated genes were found to be 3.53,2.88 and 5.26 per cent (the percent values were calculated by finding its proportional hits among total hits obtained) in Gir, Kankrej and crossbred cattle, respectively.