Genome Mining and Comparative Genomic Analysis of Five Coagulase- Negative Staphylococci (CNS) Isolated from Human Colon and Gall Bladder

Gurwinder Kaur,Ramesan Girish Nair

doi:10.4172/2153-0602.1000192

Abstract

Coagulase-negative Staphylococci (CNS) are known to cause distinct types of infections in humans like endocarditis and urinary tract infections (UTI). Surprisingly, there is a lack of genome analysis data in literature against CNS particularly of human origin. In light of this, we performed genome mining and comparative genomic analysis of CNS strains Staphylococcus cohnii subsp. cohnii strain GM22B2, Staphylococcus equorum subsp. strain equorum G8HB1, Staphylococcus pasteuri strain BAB3 isolated from gall bladder and Staphylococcus haemolyticus strain 1HT3, Staphylococcus warneri strain 1DB1 isolated from colon. We identified 29% of shared virulence determinants in the CNS strains which involved resistance to antibiotics and toxic compounds, bacteriocins and ribosomally synthesized peptides, adhesion, invasion, intracellular resistance, prophage regions, pathogenicity islands. 10 unique virulence factors involved in adhesion, negative transcriptional regulation, resistance to copper and cadmium, phage maturation were also present in our strains. Apart from comparing the genome homology, size and G + C content, we also showed the presence 10 different CRISPR-cas genes in the CNS strains. Further, KAAS based annotation revealed the presence of CNS genes in different pathways involved in human diseases. In conclusion, this study is a first attempt to unveil the pathogenomics of CNS isolated from two distinct body organs and highlights the importance of CNS as emerging pathogens of health care sector.

Highlights

The genus Staphylococcus is very well characterized consisting of fifty one species and twenty seven sub-species
The variation in the genomic G + C content among the Coagulase-negative Staphylococci (CNS) species could be attributed to mutation and selection pressures [36,37] which may arise due to multiple factors like environment [38], symbiotic lifestyle [39], aerobiosis [40], and nitrogen fixing ability [41]
There was a slight variation in the rRNA operons and tRNA coding genes (Table 1) among the CNS species, which could be correlated with the strength of codon usage bias value known as the S value

Summary

Introduction

The genus Staphylococcus is very well characterized consisting of fifty one species and twenty seven sub-species (www.bacterio.net/ staphylococcus.html). The human body consists of a vast repertoire of bacteria, among which the genus Staphylococcus represents the proportion of bacteria that can cause severe infections to the host and majority of these colonize inside new born babies through mother‘s skin [8,9]. Staphylococcus aureus is a major pathogen in the genus that causes endovascular infections, pneumonia, septic arthritis, endocarditis, osteomyelitis, foreign-body infections and sepsis in hospitals and outpatients [10,11,12,13]. Second most important are those CNS that target neonates through intravascular catheters, prosthetic devices, post-operative sternal wound infections and immune-compromised hosts in the health care environment [14,15,16]. CNS are gradually developing drug resistance characteristics, which limits present therapies and poses a great threat to the health care system worldwide [8,14,17,18,19,20,21]

Methods

Results

Conclusion