The Comparison of Streptococcus agalactiae Isolated from Fish and Bovine using Multilocus Sequence Typing

Angela Mariana Lusiastuti,Helga Seeger,Agustin Indrawati,Michael Zschöck

doi:10.4308/hjb.20.4.157

Angela Mariana Lusiastuti, Helga Seeger + Show 2 more

Open Access

https://doi.org/10.4308/hjb.20.4.157

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Abstract

Multilocus sequence typing (MLST) has greater utility for determining the recent ancestral lineage and the relatedness of individual strains. Group B streptococci (GBS) is one of the major causes of subclinical mastitis of dairy cattle in several countries. GBS also sporadically causes epizootic infections in fish. The aim of this study was to compare the evolutionary lineage of fish and bovine isolates in relation to the S. agalactiae global population as a whole by comparing the MLST profiles. Twenty S. agalactiae isolates were obtained from dairy cattle and fish. PCR products were amplified with seven different oligonucleotide primer pairs designed from the NEM316 GBS genome sequence. Clone complexes demonstrated that bovine and fish isolates were separate populations. These findings lead us to conclude that fish S. agalactiae is not a zoonotic agent for bovine. MLST could help clarify the emergence of pathogenic clones and to decide whether the host acts as a reservoir for another pathogenic lineage.

Highlights

Several molecular typing methods have been used to investigate the epidemiology of Streptococcus agalactiae
Fish-isolates suspected Group B streptococci (GBS) obtained from the brain, head kidney, eye, and liver were cultured on 5% Columbia sheep blood agar
The results of CAMP factor production revealed that all of the bovine isolates were positive while fish isolates were CAMP negative

Summary

Introduction

Several molecular typing methods have been used to investigate the epidemiology of Streptococcus agalactiae. MLST can be represented by a number of digits corresponding to the allelic number of each of the loci being used. This greatly facilitates inter laboratory comparisons and the study of global epidemiology (Feil & Enright 2004). Lancefield (1934) recognized GBS as a human pathogen before 1960 but only in sporadic cases (Anthony & Okada 1977; Trijbels-Smeulders et al 2004). Streptococcus agalactiae, GBS, is an important human pathogen, and the leading cause of septicaemia, meningitis and pneumonia in neonates, responsible for two to three cases per 1000 live b__i_r_th__.__G__B__S____a_lso sporadically causes epizootic

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