Antimicrobial susceptibility profiles, serotype distribution and virulence determinants among invasive, non-invasive and colonizing Streptococcus agalactiae (group B streptococcus) from Malaysian patients

Abstract

A total of 103 group B streptococci (GBS) including 22 invasive, 21 non-invasive, and 60 colonizing isolates were collected in a Malaysian hospital (June 2010–October 2011). Isolates were characterized by conventional and molecular serotyping and analyzed for scpB, lmb, hylB, cylE, bac, bca and rib gene content. Antimicrobial susceptibility to penicillins, macrolides, lincosamides, quinolones and tetracyclines was determined using disk diffusion and the MICs for penicillin were determined by E-test. Molecular serotyping for all eight serotypes (Ia, Ib, II–VII) was in full accordance with conventional serotyping. Overall, taking CS and MS together, serotype VI was the most common capsular type (22.3 %) followed by VII (21.4 %), III (20.4 %), Ia (17.5 %), V (9.7 %), II (7.7 %) and IV (1 %). Susceptibility to beta-lactam antimicrobials was prevalent (100 %). Resistance rates for erythromycin, clindamycin and tetracycline were 23.3 %, 17.5 % and 71.8 %, respectively. PCR-virulence gene screening showed the presence of cylE, lmb, scpB and hylB in almost all the isolates while rib, bca, and bac genes were found in 29.1 %, 14.6 % and 9.7 % of the isolates. Certain genes were significantly associated with specific serotypes, namely, rib with serotypes Ia, II, III and VI; bca and bac with serotypes II and III. Furthermore, serotype Ia was significantly more common among patients with invasive infections (p < 0.01) and serotype VI isolates were significantly more common among carriers (p < 0.05). In summary, serotype distribution correlates with virulence gene content will be useful in epidemiological studies and design of vaccines.

Study of Serotypes, Susceptibility to Macrolide and Virulence and Resistance Molecular Profiles in Invasive Strains of &lt;i&gt;Streptococcus agalactiae&lt;/i&gt; in Two Argentine Provinces

“…In this study scpB, lmb, hylB, rib, bca and bac genes were detected more frequently that in studies performed by other authors [18] [51]. This could be due to the disparity in the number and kind of worked strains (our study did not include colonizing strains isolated from pregnant women).…”

Molecular serotyping, virulence gene profiling and pathogenicity of Streptococcus agalactiae isolated from tilapia farms in Thailand by multiplex PCR

“…Neither bac nor bca was detected in serotype Ia isolated from patients in Malaysia (Eskandarian et al . ), whereas a variety of bac and bca combinations ( bac + / bca + / bac + , bca + / bac − and bca − ) were detected in patients in Brazil (Dutra et al . ).…”

Evaluation of Antimicrobial Susceptibility of Streptococcus agalactiae Isolates from Patients with Urinary Tract Infection (UTI) Symptoms

“…The antimicrobial susceptibility testing was carried out using the antibiotics that were considered to have potential clinical utility for the prophylaxis and treatment of GBS infections and/or colonization therefore had susceptibility breakpoints recommended by the (CLSI) Guidelines 2012. The evaluated results of antibiotic susceptibility tests in this study indicated that approximately all isolated uropathogenic GBS strains were uniformly sensitive to penicillinin vitro, as different authors around the world reported it (15,16). In the reports from Iran, many studies have also shown high susceptibility of GBS isolates to Penicillin G and ampicillin; for example, Jannati et al indicated susceptibility of all GBS isolates to these antibiotics, although there is a report of high resistance (89.4%) to penicillin among uropathogenic GBS isolates by Rahbar and colleagues (17,18).…”

“…The increasing tendency in the rate of resistance to clindamycin and erythromycin among GBS strains has enhanced worry about the use of the antimicrobial agents as alternative agents for the prophylaxis or treatment of GBS infections. Plasmid-mediated resistance to antimicrobial agents has also been expected to occur in GBS and can facilitate the development of multidrug resistance (13)(14)(15).…”