O.R. Vinodh Kumar

Spatial molecular epidemiology of carbapenem‐resistant and New Delhi metallo beta‐lactamase (blaNDM)‐producing Escherichia coli in the piglets of organized farms in India

A cross‐sectional study was conducted in 10 government‐organized pig farms between 2014 and 2016 representing seven states of India to understand the epidemiology of carbapenem resistance in the Escherichia coli.

Development of slide ELISA (SELISA) for detection of four poultry viral pathogens by direct heat fixation of viruses on glass slides.

The development of an easy and simpler method of slide enzyme-linked immunosorbent assay (SELISA) for the diagnosis of four economically important poultry viruses viz., Newcastle disease virus (NDV), infectious bronchitis virus (IBV), infectious bursal disease virus (IBDV) and egg drop syndrome 76 virus (EDS 76) and the use of SELISA for semi quantitation of NDV are described. The positive signals for viral aggregates were detected under light microscope. This is the first report regarding the development of SELISA based on heat fixation for the diagnosis of viral pathogens.

Molecular characterisation of bla OXA48 carbapenemase, extended spectrum beta −lactamase (ESBL) and Shiga toxin producing Escherichia coli isolated from farm piglets of India

OBJECTIVES The aim of this study was to characterise carbapenemase-, extended-spectrum β-lactamase (ESBL)- and Shiga toxin-producing Escherichia coli isolated from farm piglets in India. METHODS Faecal samples (n=741) from 10 organised pig farms, including non-diarrhoeic (n=546) and diarrhoeic (n=195) piglets, were processed for isolation of carbapenem-resistant and ESBL-producing E. coli. RESULTS A total of 27 and 243 isolates were phenotypically confirmed as carbapenem-resistant and ESBL-producers, respectively. The meropenem minimum inhibitory concentration (MIC) of carbapenem-resistant isolates ranged from 8-128μg/mL. On genotypic screening of the 27 carbapenem-resistant isolates, 3 isolates were positive for the blaOXA-48 carbapenemase gene; no other carbapenemase genes were detected. The 243 ESBL-producing isolates were positive for blaCTX-M-1 (n=135), qnrA (n=92), qnrB (n=112), qnrS (n=49), tetA (n=42), tetB (n=45) and sul1 (n=43). The Shiga toxin virulence markers stx1 and stx2 were detected in 41 and 38 of the 243 phenotypic ESBL-producing isolates, respectively. Multilocus sequence typing (MLST) of blaOXA-48-positive E. coli isolates showed ST10- and ST5053-like sequence types. CONCLUSION This is the first report on the presence of blaOXA-48-carrying E. coli in piglets in India, which pose a potential risk to public health.

Clinicopathological characterization of experimental infection in chickens with sub-genotype VIIi Newcastle disease virus isolated from peafowl

Newcastle disease (ND) is an economically important viral disease distressing poultry industry across the globe. Herein, we report the clinicopathology of sub-genotype VIIi Newcastle disease virus (NDV) isolated from peafowl in chickens. The virus isolate produced systemic infection with prominent tropism in visceral organs in chicken, confirmed on the basis of gross and microscopic lesions, and immunohistochemistry findings. The experimentally infected chickens exhibited 100% mortality with severe hemorrhagic lesions in the proventriculus and intestine, especially marked lymphocytolysis in spleen and bursa. The virus could be re-isolated from the cloacal swabs of infected chickens during 4th to 6th dpi (on 6th dpi all birds died), and all were tested positive in conventional RT-PCR. This is the first report on clinicopathology of NDV isolated from peafowl and/or sub-genotype VIIi NDV in experimentally infected chickens. Explorative epidemiological and molecular studies are suggested to screen wild peafowls and poultry flocks of the country for establishing the occurrence of this sub-genotype and opting for appropriate prevention and control strategies.