Group B streptococcal disease in nonpregnant patients: emergence of highly resistant strains of serotype Ib in Taiwan in 2006 to 2008

Antibiotic resistance, biofilm formation, and virulence genes of Streptococcus agalactiae serotypes of Indian origin

BACKGROUND

Group B Streptococcus (GBS) is a causative agent of various infections in newborns, immunocompromised (especially diabetic) non-pregnant adults, and pregnant women. Antibiotic resistance profiling can provide insights into the use of antibiotic prophylaxis against potential GBS infections. Virulence factors are responsible for host-bacteria interactions, pathogenesis, and biofilm development strategies. The aim of this study was to determine the biofilm formation capacity, presence of virulence genes, and antibiotic susceptibility patterns of clinical GBS isolates.

RESULTS

The resistance rate was highest for penicillin (27%; n = 8 strains) among all the tested antibiotics, which indicates the emergence of penicillin resistance among GBS strains. The susceptibility rate was highest for ofloxacin (93%; n = 28), followed by azithromycin (90%; n = 27). Most GBS strains (70%; n = 21) were strong biofilm producers and the rest (30%; n = 9) were moderate biofilm producers. The most common virulence genes were cylE (97%), pavA (97%), cfb (93%), and lmb (90%). There was a negative association between having a strong biofilm formation phenotype and penicillin susceptibility, according to Spearman's rank correlation analysis.

CONCLUSION

About a third of GBS strains exhibited penicillin resistance and there was a negative association between having a strong biofilm formation phenotype and penicillin susceptibility. Further, both the strong and moderate biofilm producers carried most of the virulence genes tested for, and the strong biofilm formation phenotype was not associated with the presence of any virulence genes.

Genotype Distribution and Antibiotic Susceptibility Pattern of Clinical Isolates of Group B Streptococcus in a Tertiary Care Hospital in Puducherry, South India

Background

Streptococcus agalactiae apart from being a colonizer in the genital region is also associated with several other invasive infections in all age groups. With the varied distribution of serotypes across different regions of the world, universal vaccination is also unattainable. However, in India, the knowledge of group B Streptococcus (GBS) genotype distribution is deficient. Thus, this study was initiated to add data on this aspect. Methodology. A cross-sectional study was conducted using isolates of group B Streptococcus from all clinical specimens. Along with that, the clinical specimen type and the antibiotic resistance profile of the isolates were correlated with the genotypes recognized through a multiplex PCR assay.

Results

Among the 86 isolates subjected to multiplex PCR for genotype identification, five genotypes were identified with genotype Ib as the predominant one (34.9%), followed by III (20.9%), II (16.3%), Ia (12.7%), and V (11.6%).

Conclusion

The results demonstrated a correlation of types Ib and III with vaginal colonization and type II with urine specimens in the current study. This preliminary study exhibited the distribution of common genotypes and their antibiotic resistance profiles in various GBS isolates. However, multiple studies across the country with larger sample sizes are needed to validate these findings.

Emergence of Multi-Drug Resistance and Its Association With Uncommon Serotypes of Streptococcus agalactiae Isolated From Non-neonatal Patients in Thailand

Group B streptococcus (GBS) or Streptococcus agalactiae is an opportunistic pathogen that causes serious illness in newborns, pregnant women, and adults. However, insufficient detection methods and disease prevention programs have contributed to an increase in the incidence and fatality rates associated with this pathogen in non-neonatal patients. This study aimed to investigate factors of the observed increased incidence by investigation of serotype distribution, virulence factors, and antimicrobial susceptibility patterns from invasive GBS disease among non-neonatal patients in Thailand. During 2017–2018, a total of 109 S. agalactiae isolates were collected from non-pregnant patients. There were 62 males and 47 females, with an average age of 63.5 years (range: 20 – 96). Serotypes were determined by latex agglutination assay and multiplex polymerase chain reaction (PCR)-based assay. Among those isolates, seven virulence genes (rib, bca, pavA, lmb, scpB, cylE, and cfb) were detected by PCR amplification, and were determined for their susceptibility to 20 antimicrobial agents using a Sensititre^TM Streptococcus species STP6F AST plate. Among the study isolates, serotype III was predominant (52.3%), followed by serotype V and serotype VI (13.8% for each), serotype Ib (11.9%), and other serotypes (8.2%). Of the seven virulence genes, pavA was found in 67.0%. Except for one, there were no significant differences in virulence genes between serotype III and non-serotype III. Study isolates showed an overall rate of non-susceptibility to penicillin, the first-line antibiotic, of only 0.9%, whereas the resistance rates measured in tetracycline, clindamycin, azithromycin, and erythromycin were 41.3, 22.0, 22.0, and 22.0%, respectively. Strains that were resistant to all four of those drugs were significantly associated with non-serotype III (p < 0.001). Using multi-locus sequence typing (MLST), 40.0% of the four-drug-resistant isolates belonged to serotype VI/ST1, followed by serotype Ib/ST1 (35.0%). Cluster analysis with global GBS isolates suggested that the multiple drug-resistant isolates to be strongly associated with the clonal complex (CC) 1 (p < 0.001). Compared to the 2014 study of 210 invasive GBS isolates conducted in 12 tertiary hospitals in Thailand, the proportion of serotype III has dramatically dropped from nearly 90% to about 50%. This suggests that resistances to the second-line antibiotics for GBS might be the selective pressure causing the high prevalence of non-serotype III isolates.

An 18-year retrospective study on the epidemiology of early-onset neonatal sepsis - emergence of uncommon pathogens

BACKGROUND

Nationwide group B Streptococcus agalactiae (GBS) antepartum screening was instituted in Taiwan in 2012. The impact of the policy on early-onset sepsis (EOS) has not been evaluated. This study aimed to examine the impact of the policy on the incidence of neonatal EOS.

METHODS

This was a retrospective study conducted at MacKay Children's Hospital. Patients with culture-proven neonatal EOS were enrolled and divided by birth year in relation to the implementation of GBS prevention policy: Epoch 1, 2001-2004 pre-GBS screening; Epoch 2, 2005-2011 elective GBS screening; and Epoch 3, 2012-2018 universal GBS screening. The pathogens and antimicrobial resistance patterns were reviewed and analyzed. The incidence was modeled using Poisson regression.

RESULTS

A total of 128 neonates met the enrollment criteria. The observed incidence of EOS was 1.52‰. The incidence rates of EOS, GBS, and Escherichia coli (E. coli) sepsis were similar in Epoch 1 and Epoch 3. E. coli and non-Enterococcal group D Streptococcus (GDS) infection increased significantly in term infants, whereas the EOS-related mortality rate declined in preterm infants. Approximately 72% of the isolated E. coli were ampicillin-resistant, and the antimicrobial sensitivity remained unaltered during the studied period.

CONCLUSIONS

The overall EOS incidence has not changed from 2001 to 2018. However, changes in the causative pathogens were observed in both term and preterm infants. Clinicians should be aware of this evolving epidemiology to provide prompt appropriate perinatal management.

Prevalence of group B streptococcus colonization in pregnant women in Jiangsu, East China

Background

Group B streptococcus (GBS) is the leading cause of early-onset neonatal sepsis. However, GBS was infrequently reported in the developing world in contrast to western countries. This study assessed the prevalence of GBS colonization among pregnant women in Jiangsu, East China, and revealed the difference of GBS infection between culture and PCR.

Methods

A total of 16,184 pregnant women at 34 to 37 weeks’ gestation aged 16–47 years were recruited from Nanjing Kingmed Center for Clinical Laboratory. Nine thousand twenty-two pregnant women received GBS screening by PCR detection only. Seven thousand one hundred sixty-two pregnant women received GBS screening by bacterial culture and GBS-positive samples were tested for antibiotic resistance.

Results

The overall GBS positive rate was 8.7% by PCR and 3.5% by culture. Colonization rate was highest in the “25–29 years” age group. The 249 GBS-positive samples which detected by culture were all sensitive to penicillin. The prevalence of resistance to erythromycin, clindamycin, and levofloxacin was 77.5, 68.3, and 52.2%, respectively.

Conclusions

This study revealed the data on the prevalence of GBS colonization in pregnant women at 34 to 37 weeks’ gestation in Jiangsu, East China. It compared the difference of the sensitivity to detect GBS between PCR and culture. PCR was expected to become a quick method in pregnancy women conventional detection of GBS infection.

Distribution of Pilus island and antibiotic resistance genes in Streptococcus agalactiae obtained from vagina of pregnant women in Yazd, Iran

Background and Objectives:

Due to the important role of Streptococcus agalactiae, Group B streptococci (GBS), in production of invasive disease in neonates, investigation regarding the pathogenicity and antibiotic resistance factors is necessary in selecting the appropriate therapeutic agents. Beside capsule, the pilus has been currently recognized as an important factor in enhancing the pathogenicity of GBS. Resistance of GBS to selected antibiotics is noticeably increasing which is mainly due to the anomalous use of these drugs for treatment. The aim of this study was to determine the prevalence of pili genes followed by antibiotic susceptibility of GBS, previously serotyped, isolated from pregnant women in the city of Yazd, Iran.

Materials and Methods:

Fifty seven GBS from pregnant women were subjected to multiplex PCR for determination of PI-1, PI-2a and PI-2b pilus-islands and simultaneously, the phenotype of antibiotic resistance to penicillin, tetracycline, erythromycin, clindamycin, gentamycin and levofloxacin was determined. Antibiotic resistance genes (ermA, ermB, mefA, tetM, int-Tn) were further diagnosed using PCR and multiplex PCR.

Results:

PI-1+PI-2a with 71.9%; followed by PI-2a (21.1%) and PI-2b (7%) were observed. PI-1+PI-2a in serotype III was (73.2%), serotype II, Ia, Ib and V were 12.2%, 9.8%, 2.4% and 2.4% respectively. GBS penicillin sensitive was 89.5% and 96.5% resistance to tetracycline. The frequency of resistance genes were as follows: tetM (93%), ermA (33.3%), ermB (8.8%), int-Tn (80.7%) and mefA (0).

Conclusion:

Majority of GBS contained PI-1+PI-2a. Hence presence of this pilus stabilizes the colonization, therefore designing a program for diagnosing and treatment of infected pregnant women seems to be necessary.

Emerging serotype III sequence type 17 group B streptococcus invasive infection in infants: the clinical characteristics and impacts on outcomes

BACKGROUND

Group B Streptococcus (GBS) is an important pathogen that causes high mortality and morbidity in young infants. However, data on clinical manifestations between different GBS serotypes and correlation with molecular epidemiology are largely incomplete. The aim of this study was to determine the serotype distribution, antimicrobial resistance, clinical features and molecular characteristics of invasive GBS isolates recovered from Taiwanese infants.

METHODS

From 2003 to 2017, 182 non-duplicate GBS isolates that caused invasive disease in infants less than one year of age underwent serotyping, multilocus sequence typing (MLST) and antibiotic susceptibility testing. The clinical features of these infants with GBS disease were also reviewed.

RESULTS

Of the 182 patients with invasive GBS disease, 41 (22.5%) were early-onset disease, 121 (66.5%) were late-onset disease and 20 (11.0%) were late late-onset disease (> 90 days of age). All these patients were treated with effective antibiotics on time. Among them, 51 (28.0%) had meningitis, 29 (16.0%) had neurological complications, 12 (6.6%) died during hospitalization, and 15 (8.8%) out of 170 patients who survived had long-term neurological sequelae at discharge. Serotype III GBS strains accounted for 64.8%, followed by serotype Ia (18.1%) and Ib (8.2%). MLST analysis revealed 11 different sequence types among the 182 isolates and ST-17 was the most dominant sequence type (56.6%). The correlation between serotype III and ST17 was evident, as ST17 accounted for 87.3% of all serotype III isolates. There was an obvious increasing trend of type III/ST-17 GBS that caused invasive disease in infants. All isolates were susceptible to penicillin, cefotaxime, and vancomycin, while 68.1 and 65.9% were resistant to erythromycin and clindamycin, respectively.

CONCLUSIONS

Despite timely and appropriate antibiotic treatment, a significant proportion of invasive GBS disease still inevitably causes adverse outcomes. Further study to explore preventive strategies and development of serotype-based vaccines will be necessary in the future.

Molecular Characteristics and Antimicrobial Resistance of Group B Streptococcus Strains Causing Invasive Disease in Neonates and Adults

We aimed to analyze the molecular characteristics, clonality and antimicrobial resistance profiles of group B streptococcus (GBS) isolates collected in Taiwan from invasive diseases and carriage. Multilocus sequence typing (MLST) was used to assess the genetic diversity of 225 GBS strains from neonates and adults with invasive GBS diseases. 100 GBS strains collected from colonized pregnant women during the same period were compared, and all strains were characterized for one of nine capsule genotypes. We also determined the susceptibilities of all GBS isolates to various antimicrobial agents. The most frequently identified serotypes that caused invasive disease in neonates were III (60.6%) and Ia (17.3%), whereas type VI (32.7%), Ib (19.4%), and V (19.4%) were the most common to cause invasive disease in adults. Serotype VI was the leading type that colonized pregnant women (35.0%). Twenty-six sequence types (STs) were identified, and 90.5% of GBS strains were represented by 6 STs. ST-17 and ST-1 were more prevalent in invasive diseases in neonates and adults, respectively. The majority of serotype III and VI isolates belonged to clonal complex (CC)-17 and CC-1, respectively. ST-17 strains were more likely to cause meningitis and late-onset disease than other strains. In addition, ST-12 and ST-17 GBS strains showed the highest rate of resistance to erythromycin and clindamycin (range: 75.8–100%). In conclusion, CC-17/type III and CC-1/type VI are the most important invasive pathogens in infants and non-pregnant adults in Taiwan, respectively. GBS genotypes vary between different age groups and geographical areas and should be considered during GBS vaccine development.

Genetic and pathogenic difference between Streptococcus agalactiae serotype Ia fish and human isolates

Background

Streptococcus agalactiae (GBS) is a common pathogen to infect newborn, woman, the elderly, and immuno-compromised human and fish. 37 fish isolates and 554 human isolates of the GBS in 2007–2012 were investigated in serotypes, antibiotic susceptibility, genetic difference and pathogenicity to tilapia.

Results

PCR serotyping determined serotype Ia for all fish GBS isolates and only in 3.2 % (3–4.2 %) human isolates. For fish isolates, all consisted a plasmid less than 6 kb and belonged to ST7 type, which includes mainly pulsotypes I and Ia, with a difference in a deletion at the largest DNA fragment. These fish isolates were susceptible to all antimicrobials tested in 2007 and increased in non-susceptibility to penicillin, and resistance to clindamycin and ceftriaxone in 2011. Differing in pulsotype and lacking plasmid from fish isolates, human serotype Ia isolates were separated into eight pulsotypes II–IX. Main clone ST23 included pulsotypes II and IIa (50 %) and ST483 consisted of pulsotype III. Human serotype Ia isolates were all susceptible to ceftriaxone and penicillin and few were resistant to erythromycin, azithromycin, clindamycin, levofloxacin and moxifloxacine with the resistant rate of 20 % or less. Using tilapia to analyze the pathogenesis, fish isolates could cause more severe symptoms, including hemorrhage of the pectoral fin, hemorrhage of the gill, and viscous black and common scites, and mortality (>95 % for pulsotype I) than the human isolates (<30 %); however, the fish pulostype Ia isolate 912 with deletion caused less symptoms and the lowest mortality (<50 %) than pulsotype I isolates.

Conclusion

Genetic, pathogenic, and antimicrobial differences demonstrate diverse origin of human and fish serotype Ia isolates. The pulsotype Ia of fish serotype Ia isolates may be used as vaccine strains to prevent the GBS infection in fish.

Electronic supplementary material

The online version of this article (doi:10.1186/s12866-016-0794-4) contains supplementary material, which is available to authorized users.

Genetically diverse serotypes III and VI substitute major clonal disseminated serotypes Ib and V as prevalent serotypes of Streptococcus agalactiae from 2007 to 2012

BACKGROUND

Streptococcus agalactiae [group B Streptococcus (GBS)] has become more prevalent in nonpregnant women, the elderly, and people who are immunocompromised. We investigated the serotype and genomic changes of GBS human isolates from different hospitals from 2007 to 2012.

METHODS

The serotype and genotype of 658 GBS human isolates were determined with multiplex polymerase chain reaction and pulsed field gel electrophoresis analysis. Multilocus sequence typing analysis determined the sequence type (ST) of the major clones of serotypes Ib, V, and VI.

RESULTS

Most of the isolates were collected from urine samples (60.5%) with a reduction in the rate from 74.6% in 2007 to 34.5% in 2012 and from infected patients older than 30 years (72.6%). The female/male ratio differed depending on the source: 3.52 in the urine group, 0.48 in the wound group, and 0.43 in pus. Serotypes Ib (16.5%), III (16.9%), V (27.2%), and VI (17.6%) were the most predominant among the nine serotypes identified and were separated into two prevalence patterns: a decrease in serotypes Ib and V and an increase in serotypes III and VI from 2007 to 2012. The prevalence change was associated with the urine group. Additionally, serotype VI become more prevalent in blood samples in four hospitals. The pulsed field gel electrophoresis analysis demonstrated three genetic patterns: limited pulsotypes and a major clonal dissemination for serotypes Ib and V, diverse pulsotypes for serotypes III, and diverse pulsotypes with a major clonal dissemination for serotype VI. Multilocus sequence typing analysis of the major clones identified ST12 for serotype Ib and ST1 for serotypes V and VI.

CONCLUSION

Rapid genomic variations with different evolutionary patterns have led to the establishment of serotypes III and VI as the predominant GBS serotypes.

Clonal dissemination of invasive and colonizing clonal complex 1 of serotype VI group B Streptococcus in central Taiwan

BACKGROUND/PURPOSE

The aim of this study was to investigate clinical presentation, serotype distribution and genetic correlation of group B streptococcus (GBS) diseases. Since serotype VI prevalence far exceeded that reported in prior studies, genetic relationship of isolates was further analyzed.

METHODS

GBS isolates obtaining from patients with invasive diseases and pregnant women with colonization between June 2007 and December 2010 were analyzed. All isolates were tested for serotypes by multiplex PCR assay and pulsed-field gel electrophoresis (PFGE). Serotype VI isolates were further analyzed by multilocus sequence typing (MLST).

RESULTS

A total of 134 GBS isolates were recovered from blood of 126 patients with invasive disease (94.0%) and anogenital swabs of 8 pregnant women (6.0%). Most common serotype was Ib (21.6%), followed by V (20.1%), VI (18.7%), III (15.7%), II (11.9 %), Ia (11.2%), and IX (0.7%). Serotype VI was also the leading type in infants with early onset disease (EOD; 3/8, 37.5%) and colonizing pregnant women (3/8, 37.5%). PFGE distinguished 33 pulsotypes, reflecting genetic diversity among GBS isolates. Among 25 serotype VI isolates tested, 14 were ST-1, seven were ST-679, three were ST-678, one was ST-681, and distributed into four PFGE pulsotypes. ST-678, ST-679, and ST-681 were novel sequence types; ST-678 and ST-679 are single-locus variants of ST-1 that belongs to clonal complex (CC) 1.

CONCLUSION

CC1 dissemination of serotype VI GBS thus emerges as an important invasive pathogen in infants and nonpregnant adults in central Taiwan. Serotype prevalence of GBS must be continuously monitored geographically to guide prevention strategy of GBS vaccines.

Human Streptococcus agalactiae strains in aquatic mammals and fish

BACKGROUND

In humans, Streptococcus agalactiae or group B streptococcus (GBS) is a frequent coloniser of the rectovaginal tract, a major cause of neonatal infectious disease and an emerging cause of disease in non-pregnant adults. In addition, Streptococcus agalactiae causes invasive disease in fish, compromising food security and posing a zoonotic hazard. We studied the molecular epidemiology of S. agalactiae in fish and other aquatic species to assess potential for pathogen transmission between aquatic species and humans.

METHODS

Isolates from fish (n = 26), seals (n = 6), a dolphin and a frog were characterized by pulsed-field gel electrophoresis, multilocus sequence typing and standardized 3-set genotyping, i.e. molecular serotyping and profiling of surface protein genes and mobile genetic elements.

RESULTS

Four subpopulations of S. agalactiae were identified among aquatic isolates. Sequence type (ST) 283 serotype III-4 and its novel single locus variant ST491 were detected in fish from Southeast Asia and shared a 3-set genotype identical to that of an emerging ST283 clone associated with invasive disease of adult humans in Asia. The human pathogenic strain ST7 serotype Ia was also detected in fish from Asia. ST23 serotype Ia, a subpopulation that is normally associated with human carriage, was found in all grey seals, suggesting that human effluent may contribute to microbial pollution of surface water and exposure of sea mammals to human pathogens. The final subpopulation consisted of non-haemolytic ST260 and ST261 serotype Ib isolates, which belong to a fish-associated clonal complex that has never been reported from humans.

CONCLUSIONS

The apparent association of the four subpopulations of S. agalactiae with specific groups of host species suggests that some strains of aquatic S. agalactiae may present a zoonotic or anthroponotic hazard. Furthermore, it provides a rational framework for exploration of pathogenesis and host-associated genome content of S. agalactiae strains.

Human Streptococcus agalactiae strains in aquatic mammals and fish

Background

In humans, Streptococcus agalactiae or group B streptococcus (GBS) is a frequent coloniser of the rectovaginal tract, a major cause of neonatal infectious disease and an emerging cause of disease in non-pregnant adults. In addition, Streptococcus agalactiae causes invasive disease in fish, compromising food security and posing a zoonotic hazard. We studied the molecular epidemiology of S. agalactiae in fish and other aquatic species to assess potential for pathogen transmission between aquatic species and humans.

Methods

Isolates from fish (n = 26), seals (n = 6), a dolphin and a frog were characterized by pulsed-field gel electrophoresis, multilocus sequence typing and standardized 3-set genotyping, i.e. molecular serotyping and profiling of surface protein genes and mobile genetic elements.

Results

Four subpopulations of S. agalactiae were identified among aquatic isolates. Sequence type (ST) 283 serotype III-4 and its novel single locus variant ST491 were detected in fish from Southeast Asia and shared a 3-set genotype identical to that of an emerging ST283 clone associated with invasive disease of adult humans in Asia. The human pathogenic strain ST7 serotype Ia was also detected in fish from Asia. ST23 serotype Ia, a subpopulation that is normally associated with human carriage, was found in all grey seals, suggesting that human effluent may contribute to microbial pollution of surface water and exposure of sea mammals to human pathogens. The final subpopulation consisted of non-haemolytic ST260 and ST261 serotype Ib isolates, which belong to a fish-associated clonal complex that has never been reported from humans.

Conclusions

The apparent association of the four subpopulations of S. agalactiae with specific groups of host species suggests that some strains of aquatic S. agalactiae may present a zoonotic or anthroponotic hazard. Furthermore, it provides a rational framework for exploration of pathogenesis and host-associated genome content of S. agalactiae strains.

High prevalence of fluoroquinolone-resistant group B streptococci among clinical isolates in China and predominance of sequence type 19 with serotype III

A total of 146 group B streptococcus isolates from 8 cities across China belonged to four serotypes. Serotype Ia was more common in children. A high prevalence of resistance was observed for levofloxacin (37.7%), erythromycin (71.2%), clindamycin, (53.4%), and tetracycline (81.5%). The levofloxacin and clindamycin resistances among the 4 serotypes differed significantly. Eighty percent of fluoroquinolone-resistant isolates belonged to the sequence type 19 (ST19)/serotype III clone, with GyrA-ParC-ParE triple substitutions. This clone carried the erm(B), mef(E), and tet(M) genes.

Capsular serotype and antibiotic resistance of group B streptococci isolated from pregnant women in Ardabil, Iran

BACKGROUND AND OBJECTIVES

Group B Streptococci (GBS) is a major cause of neonatal and maternal infections. The aim of this study was to determine the serotype distribution and antibiotic resistance profile of GBS strains isolated from pregnant women in Ardabil.

MATERIALS AND METHODS

Antibiotic resistance of 56 GBS isolates was investigated using E-test strips and disk-diffusion method. Serotyping was performed using capsular antiserum.

RESULTS

The results of MIC tests showed all isolates were susceptible to ampicillin, vancomycin and penicillin. One isolate (1.7%) showed reduced susceptibility pattern to penicillin (MIC; 0.25 µg/ml). There were 3 (5.3%) isolates semi-sensitive (0.25-1 µg/ml) to erythromycin (2; 0.5 µg/ml and 1; 0.38 µg/ml) and 2 (3.5%) isolates to clindamycin (1; 0.5 µg/ml, 1; 0.38 µg/ml). Additionally, 2 (3.5%) isolates were resistant to clindamycin (1; 16 µg/ml, 1; 2 µg/ml). According to the disk diffusion test, 47 (83.9%), 8 (14.2%) and 7 (12.5%) isolates were resistant to Co-trimoxazole, ciprofloxacin and ceftriaxone respectively. Serotypes V (19.6%), II (12.5%) and IV (12.5%) were the most frequent followed by serotypes III (10.7%) and VI (10.7%), Ib (8.9%), Ia (7/1%), VII (5/3%) and VIII (5/3%); 7.1% of strains were nontypeable.

CONCLUSIONS

In this study, most isolates were sensitive to common antibiotics, but increased resistance to other antibiotics indicates the importance of monitoring of antibiotic resistance in group B streptococci over time.