Molecular Detection of Hemoplasma in animals in Tamil Nadu, India and Hemoplasma genome analysis.

Hemoplasma are small pleomorphic wall-less Gram-positive bacteria that infect erythrocytes of various mammalian hosts. They generally cause asymptomatic or chronic anaemia but occasionally causes overt life-threatening hemolytic anaemia. In the present study, 316 cattle, 115 sheep, 61 goats and 6 buffalo blood samples were collected from various villages or organized farms located in nine districts of Tamil Nadu to detect the hemoplasma by PCR. Overall prevalence of 43.04%, 65.22%, and 44.26% hemoplasma DNA was observed in cattle, sheep and goats, respectively. In total, 21 hemoplasma positive samples were sequenced for 16S rRNA gene which revealed 8 Mycoplasma wenyonii, 11 'Candidatus Mycoplasma haemobos' and one Mycoplasma ovis infection. Sheep blood samples from Chennai district were infected with 'Ca. M. haemobos' whereas sheep sample from Thiruvannamalai district was infected with M. wenyonii. At least 50% genes in the hemoplasma genomes were paralogous genes whose functions were not known. Only 'Ca. M. haemolamae' genome contained one primitive CRISPR system without any cas genes. Antimicrobial resistance genes (ARG) could not be identified in any of the hemoplasma genomes but homologous ARG were identified in all the genomes. Adhesion related gene EF-Tu was detected in all 14 hemoplasma genomes but enolase gene was detected only in 'Ca. M. haemohominis' SWG34-3 genome. This is the first report on the prevalence of hemoplasma infection in cattle, sheep and goat in India.

Staphylococcus coagulans possesses many virulence factors of Staph. aureus and Staph. pseudintermedius.

AIMS: To understand the Staphylococcus coagulans prevalence in causing skin infections in dogs and detection of various virulence genes in Staph. coagulans isolates. METHODS AND RESULTS: Staph. coagulans was isolated from pus swabs collected from dogs with skin infection and identified by detecting thermonuclease, coagulase, and urease genes. The presence of methicillin-resistant gene (mecA) was performed by PCR. Antimicrobial susceptibility test was carried out by disc diffusion method. In total, 38 Staph. coagulans clinical isolates and 42 Staph. coagulans genomes available in NCBI database were screened for 19 virulence genes by PCR and in silico prediction, respectively. A prevalence of 13.8% (38/275) of Staph. coagulans dog skin infection was observed and 15.8% (6/38) of Staph. coagulans isolates carried mecA gene. Many Staph. coagulans isolates were susceptible to all tested antimicrobials. Twenty nine per cent isolates were resistant to ciprofloxacin. Genes encoding leukotoxins, DNase, exfoliative toxin, superantigen-like exotoxin, immunoglobulin-binding proteins, fibrinogen-binding proteins, autolysin, and rod shape-determining protein were detected in almost all the Staph. coagulans clinical isolates and genomes from NCBI database, whereas anti-adhesin plasma-sensitive protein genes were present in relatively lesser number of Staph. coagulans clinical isolates and genomes from NCBI database. CONCLUSIONS: Staph. coagulans possesses many virulence factors that are present in other coagulase-positive staphylococci, such as Staph. aureus and Staph. pseudintermedius. The presence of two bi-component leukotoxin genes in tandem with other virulence factor genes in a single pathogenic island in the Staph. coagulans genomes explained their eminence in the virulence of Staph. coagulans causing infections. Staph. coagulans was classified as a separate species in the year 2020 and primarily causes skin infections in dogs. Identification of this species is not included in any of the automated bacterial identification systems. Hence, many veterinary laboratories do not have a strategy to identify this bacterium. This study will help in the identification of Staph. coagulans in veterinary laboratories by PCR apart from detecting various virulence factors present in this pathogen. The existence of many virulence factors and prevalence in different animals in varied geographical locations suggest that Staph. coagulans is an important coagulase-positive staphylococcal pathogen in animals.