Streptococcus agalactiae in Brazil: serotype distribution, virulence determinants and antimicrobial susceptibility

AbstractIntroductionStreptococcus agalactiae or Group B Streptococcus (GBS) is a significant cause of neonatal sepsis. Intrapartum antibiotic prophylaxis is recommended for pregnant women identified to be recto-vaginally colonised between 34-37 weeks gestational age to decrease the risk of invasive disease in their newborns. The aim of this study was to investigate serotype distribution and antimicrobial susceptibility patterns of GBS isolates cultured from recto-vaginal specimens during pregnancy.MethodsSixty-nine archived maternal colonizing isolates were tested against penicillin, erythromycin, clindamycin, vancomycin and levofloxacin. Minimum Inhibitory Concentration (MIC) testing was performed using the E-test method. Serotyping was performed by latex agglutination method.ResultsThe most common serotypes detected were Ia (54%), III (20%), V (16%), II (6%), IV (2%) and Ib (1%), respectively. All isolates were fully susceptible to penicillin, vancomycin and levofloxacin. Eight (11%) and 50 (56%) isolates showed intermediate resistance to erythromycin and clindamycin respectively, and one isolate was resistant to erythromycin. MLSB phenomenon was noted in 3 (4%) of the isolates.ConclusionGBS colonizing isolates remain susceptible to penicillin and remains the drug of choice for intrapartum antibiotic prophylaxis and treatment of invasive disease in newbrons. Macrolides should only be used if clinically indicated due to the high prevalence of intermediate resistance. A hexavalent GBS vaccine currently under development would provide coverage for 100% of the isolates identified in this study.

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Antimicrobial susceptibility and serotype distribution of Streptococcus agalactiae rectovaginal colonising isolates from pregnant women at a tertiary hospital in Pretoria, South Africa: An observational descriptive study

South African Medical Journal ◽

10.7196/samj.2020.v110i9.14524 ◽

2020 ◽

Vol 110 (9) ◽

pp. 869

Author(s):

M Said ◽

Y Dangor ◽

N Mbelle ◽

S A Madhi ◽

G Kwatra ◽

...

Keyword(s):

South Africa ◽

Pregnant Women ◽

Antimicrobial Susceptibility ◽

Streptococcus Agalactiae ◽

Descriptive Study ◽

Tertiary Hospital ◽

Serotype Distribution ◽

Observational Descriptive Study

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Increasing Resistance and Changes in Distribution of Serotypes of Streptococcus agalactiae in Poland

Pathogens ◽

10.3390/pathogens9070526 ◽

2020 ◽

Vol 9 (7) ◽

pp. 526

Author(s):

Dorota Kaminska ◽

Magdalena Ratajczak ◽

Anna Szumała-Kąkol ◽

Jolanta Dlugaszewska ◽

Dorota M. Nowak-Malczewska ◽

...

Keyword(s):

Virulence Factors ◽

Antimicrobial Susceptibility ◽

Streptococcus Agalactiae ◽

Penicillin G ◽

Diffusion Method ◽

Virulence Determinants ◽

Group B Streptococci ◽

Disk Diffusion Method ◽

Microtiter Plate Assay ◽

Genes Encoding

Streptococcus agalactiae is responsible for serious infections in newborn babies, pregnant women, and other patients. The aim of this study was to evaluate antimicrobial susceptibility, serotype distribution, and virulence determinants of the S. agalactiae isolates derived from clinical specimens considering the global increase of both antibiotic resistance and virulence. A total of 165 isolates were identified and serotyped by PCR techniques. Antimicrobial susceptibility was assessed by disk diffusion method, gradient diffusion method and VITEK® System. Virulence associated genes were investigated by PCR; ability to form biofilm was assessed using a microtiter plate assay. The highest observed MIC value for penicillin G was 0.12 µg/mL, seen in 8.5% of isolates. Resistance to erythromycin and clindamycin were found in 30.38% and 24.8% of the strains, respectively. The serotype III (32.73%), V (25.45%), and Ia (18.18%) were found as the most frequently represented. Previously unidentified strains in Poland, belonging to serotypes VI (three strains) and VII (one strain) were recognized. The presence of genes encoding various virulence factors as well as diverse ability to form biofilm were found. In conclusion, macrolide-resistance and decreased susceptibility to penicillin G were revealed signifying the increasing resistance among group B streptococci. Moreover, the presence of genes encoding various virulence factors and the ability to form biofilm were confirmed indicating their role in the pathomechanisms of the evaluated GBS infections.

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Commensal Streptococcus agalactiae isolated from patients seen at University Hospital of Londrina, Paraná, Brazil: capsular types, genotyping, antimicrobial susceptibility and virulence determinants

BMC Microbiology ◽

10.1186/1471-2180-13-297 ◽

2013 ◽

Vol 13 (1) ◽

pp. 297 ◽

Cited By ~ 24

Author(s):

Eliane Otaguiri ◽

Ana Elisa Morguette ◽

Eliandro Tavares ◽

Pollyanna Myrella dos Santos ◽

Alexandre Morey ◽

...

Keyword(s):

Antimicrobial Susceptibility ◽

Streptococcus Agalactiae ◽

University Hospital ◽

Virulence Determinants

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Antimicrobial susceptibility, serotype distribution, virulence profile and molecular typing of piliated clinical isolates of pneumococci from east coast, Peninsular Malaysia

Scientific Reports ◽

10.1038/s41598-021-87428-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Nurul Diana Dzaraly ◽

Mohd Nasir Mohd Desa ◽

AbdulRahman Muthanna ◽

Siti Norbaya Masri ◽

Niazlin Mohd Taib ◽

...

Keyword(s):

Phylogenetic Analysis ◽

Antimicrobial Susceptibility ◽

East Coast ◽

Tertiary Hospital ◽

Multidrug Resistant ◽

Peninsular Malaysia ◽

Clinical Isolates ◽

Serotype Distribution ◽

Antimicrobial Susceptibility Test ◽

Conjugate Vaccines

AbstractPilus has been recently associated with pneumococcal pathogenesis in humans. The information regarding piliated isolates in Malaysia is scarce, especially in the less developed states on the east coast of Peninsular Malaysia. Therefore, we studied the characteristics of pneumococci, including the piliated isolates, in relation to antimicrobial susceptibility, serotypes, and genotypes at a major tertiary hospital on the east coast of Peninsular Malaysia. A total of 100 clinical isolates collected between September 2017 and December 2019 were subjected to serotyping, antimicrobial susceptibility test, and detection of pneumococcal virulence and pilus genes. Multilocus sequence typing (MLST) and phylogenetic analysis were performed only for piliated strains. The most frequent serotypes were 14 (17%), 6A/B (16%), 23F (12%), 19A (11%), and 19F (11%). The majority of isolates were resistant to erythromycin (42%), tetracycline (37%), and trimethoprim-sulfamethoxazole (24%). Piliated isolates occurred in a proportion of 19%; 47.3% of them were multidrug-resistant (MDR) and a majority had serotype 19F. This study showed ST236 was the most predominant sequence type (ST) among piliated isolates, which was related to PMEN clone Taiwan19F-14 (CC271). In the phylogenetic analysis, the piliated isolates were grouped into three major clades supported with 100% bootstrap values. Most piliated isolates belonged to internationally disseminated clones of S. pneumoniae, but pneumococcal conjugate vaccines (PCVs) have the potential to control them.

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