ABSTRACT
A study of
invasive strains of Streptococcus agalactiae (GBS) from Cordoba and Misiones,
Argentina; was conducted to determine serotypes, the susceptibility to
macrolides and molecular profiles of virulence and resistance. We studied 17
strains, recovered from cerebrospinal fluid, blood and cellulite and, a strain
of trophoblastic remnants from Misiones. The serotypes were determined by
agglutination with sera and phenotypes of resistance to
macrolide-lincosamide-streptogramin B (MLSB), were determined with the
double-disk test (D-test). The confirmation was performed by E-test by ERI and
CLI respectively that determined the minimum inhibitory concentration (MIC). Results
were interpreted as recommended by the Clinical and Laboratory Standards
Institute (CLSI) 2013. Resistance genes: ermB, ermTR and mefA and the virulence genes: bac, bca, rib, lmb, hylB, scpB, fbsA, fbsB and cylB were investigated
by conventional PCR. Serotype III (50%) and Ia (50%) were detected in Cordoba.
One strain showed cMLSB phenotype, confirmed by MIC. The same
strains showed a resistance gene ermB. All studied virulence genes were
detected in 100% of these strains. In Misiones, serotypes were III (72.7%), Ia
(18.2%) and Ib (9.1%). All strains were susceptible to CLI and ERI by D-test,
confirmed by MIC. None of the strains showed resistance genes. Virulence genes bca, rib, hylB, lmb, fbsA, fbsB and cylB were detected in 100% of the strains, bac in 81.8%
and scpB in 90.9%. Our results are in
accordance with international data, associating higher frequency of serotype
III of invasive neonatal disease followed by Ia. The presence of serotype Ib
could indicate a regional difference for Misiones. We highlight the macrolides
susceptibility in strains of Misiones and consistency in the results for
D-test, MIC and PCR for the single strain resistant phenotype cMLSB from Cordoba. The virulence genes
studied were presented with high frequency as expected for invasive strains.
Share and Cite:
Laczeski, M. , Novosak, M. , Giolito, R. , Littvik, A. , Paván, J. , Villalba, V. and Vergara, M. (2015) Study of Serotypes, Susceptibility to Macrolide and Virulence and Resistance Molecular Profiles in Invasive Strains of
Streptococcus agalactiae in Two Argentine Provinces.
Advances in Microbiology,
5, 230-243. doi:
10.4236/aim.2015.54021.