Epidemiological Characterization of Group B Streptococcus Infections in Alberta, Canada: An Update from 2014 to 2020.

Group B Streptococcus (GBS) is a leading cause of invasive neonatal disease. Epidemiological surveillance of GBS is important to determine cumulative incidence, antimicrobial resistance rates, and maternal and neonatal disease prevention. In this study, we present an update on GBS epidemiology in Alberta, Canada, from 2014 to 2020. Over the 7-year period, 1,556 GBS isolates were submitted to the Alberta Public Health Laboratory for capsular polysaccharide (CPS) typing and antimicrobial susceptibility testing. We analyzed the distribution of CPS types in Alberta and found CPS types III (23.6%), Ia (16.0%), Ib (14.8%), II (13.3%), V (12.7%), IV (12.5%), and VI (2.38%) to be the most prevalent. Less than 1% each of CPS types VII, VIII, and IX were identified. In agreement with historical data, the presence of CPS type IV continued to rise across Alberta, particularly in cases of adult infection, where a 2-fold increase was observed. Cumulative incidences of GBS cases per 100,000 population and late-onset disease per 1,000 live births increased from 4.43 to 5.36 and 0.38 to 0.41, respectively, from 2014 to 2020. However, the incidence of early-onset disease decreased during the 7-year period from 0.2 to 0.07, suggestive of successful intrapartum chemoprophylaxis treatment programs. All GBS isolates were susceptible to penicillin and vancomycin. However, nonsusceptibility to erythromycin increased significantly, from 36.85% to 50.8%, from 2014 to 2020. Similarly, nonsusceptibility to clindamycin also increased significantly, from 21.0% to 45.8%. In comparison to historical data, the overall rates of GBS infection and antimicrobial resistance have increased and the predominant CPS types have changed. IMPORTANCE This work describes the epidemiology of invasive infections caused by the bacterium group B Streptococcus (GBS) in Alberta, Canada. We show that rates of invasive GBS disease have increased from 2014 to 2020 for both adult disease and late-onset disease in neonates, whereas the rate of early onset disease in neonates has decreased. We also show that the rate of resistance to erythromycin (an antibiotic used to treat GBS) has also increased in this time.

Antibiotic resistance patterns among group B Streptococcus isolates: implications for antibiotic prophylaxis for early-onset neonatal sepsis.

STUDY/PRINCIPLES: Antibiotic prophylaxis of Group B Streptococcus (GBS) positive women during labour reduces the risk of early-onset neonatal sepsis. Penicillin is the first choice, and clindamycin and erythromycin are second choices for penicillin-allergic women. Resistance to these antibiotics is rising. The aims of this study were to evaluate the rates of clindamycin and erythromycin resistance among GBS-positive isolates cultures from pregnant women in the University Hospital of Geneva and to evaluate the legitimacy of new Centres for Disease Control and Prevention (CDC) recommendations for our context. METHODS: We collected a vagino-rectal swab from pregnant women at 35-37 weeks gestation. We recovered 124 GBS positive isolates. Identification was based on the characteristic of the colony on the chromogenic agar, the streptococcal agglutination test and confirmation by mass spectrometry. Antimicrobial susceptibility was determined by disk diffusion, according to CLSI guidelines 2010. RESULTS: The rate of resistance to clindamycin was 28% and to erythromycin was 30%. Only 3 of the 38 erythromycin resistant strains (7.9%) were susceptible to clindamycin, and only 3 out of the 35 clindamycin resistant GBS (8.6%) were identified as "inducible resistance". The rate of co-resistance to clindamycin of erythromycin-resistant strains was 92%. Penicillin remained efficacious in all cases. CONCLUSION: Rates of clindamycin and erythromycin resistance are also increasing in our context. These antibiotics should not be used for GBS neonatal sepsis prevention, without adequate antimicrobial susceptibility testing. In case of penicillin allergy and lack of antibiogramm, cephalosporins or vancomycin should be used as recommended in CDC guidelines.

Vaginal carriage and antibiotic susceptibility profile of group B Streptococcus during late pregnancy in Ismailia, Egypt.

Group B Streptococcus (GBS) infection has long been recognized as a frequent cause of morbidity and mortality in newborn infants. The purpose of this study was to determine the colonization rate with GBS and the antibiotic susceptibility profile in pregnant women attending Gynecological clinics in Egypt. One-hundred and fifty vaginal swabs were collected from pregnant women at 35-40 weeks of gestation. In comparison to culture, direct latex agglutination testing revealed 100% sensitivity and 93.75% specificity. Thirty-eight specimens (25.3%) were found to be positive for GBS. Each isolate was tested for susceptibility to penicillin G, ampicillin, cefotaxime, erythromycin, clindamycin and vancomycin. Erythromycin-resistant isolates were further classified by double-disk method. All isolates were susceptible to penicillin G, ampicillin and vancomycin. Resistance to cefotaxime was detected in three isolates (7.89%). Five isolates (13.15%) were resistant to erythromycin and nine isolates (23.68%) were resistant to clindamycin. Four (80%) isolates had constitutive macrolide-lincosamide-Streptogramin(B) resistance (cMLSB(B)) resistance and one (20%) isolate had inducible resistance (iMLS(B)) resistance. GBS colonization was found to be high in our region. Latex agglutination testing and Islam medium are reliable methods to detect GBS in late pregnancy; however, latex agglutination test is rapid and simpler. Penicillin G remains the first choice antibiotic for treatment of GBS infections.

[In vitro activity of moxifloxacin (8-methoxyquinolone) alone or in combination with cefotaxime against group B streptococci]. / Activité in vitro de la moxifloxacine (8-méthoxyquinolone) seule ou en association avec le céfotaxime sur les streptocoques du groupe B.

AIM OF THE STUDY: Our objective is to determine in vitro efficiency of moxifloxacin (MXF) alone or in combination with cefotaxime (CTX) on Group B streptococcus (GBS). MATERIALS AND METHODS: For 21 strains of GBS isolated from newborn invasive infections (6 meningitis and 15 bacteraemia), the bacterial growth in Mueller Hinton broth with MXF and/or CTX leaded to the determination of MIC and MBC, the determination of tolerance for CTX and the evaluation of the bacteriostatic action of these antibiotics combination by calculating the FIC index. Time-kill studies were conducted for MXF and CTX alone or in combination for the first four hours, with concentrations likely reached in CSF. RESULTS: Study of GBS growth with crossed concentrations of MXF and CTX showed no resistant strains, no tolerant strains, and no antagonism between MXF and CTX. Killing curves demonstrated that MXF is ten-fold more active than CTX in the first four hours. DISCUSSION: MXF is an interesting antibiotic for its good activity on the GBS, suggesting that MXF is a good candidate for further evaluation in GBS meningitis in animal model.

Vaginal & rectal carriage of Streptococcus agalactiae in the Czech Republic: incidence, serotypes distribution & susceptibility to antibiotics.

BACKGROUND & OBJECTIVES: Streptococcus agalactiae (group B streptococcus, GBS) is the predominant bacterial agent responsible for invasive perinatal infection. To obtain reliable data on vaginal and rectal carriage of S. agalactiae in pregnant women in Czech Republic, and to formulate a prevention programme of neonatal GBS disease for the Czech Republic, women at childbirth were screened for vaginal and anorectal carriage of GBS. The isolates were serotyped and tested for susceptibility to antimicrobials including those recommended for intrapartum prophylaxis. METHODS: A total of 586 women at childbirth were screened for GBS carriage in vaginal and anorectal regions using the non-enrichment and selective culture media. The isolates were serotyped by precipitation with antisera raised against various serotypes and antigenic extracts prepared according to Lancefield's modification. Mueller Hinton agar with 5 per cent defibrinated sheep blood was used for antimicrobial susceptibility testing. MIC values were evaluated according to the NCCLS criteria. RESULTS: Using selective media, GBS was detected in 172 (29.3%) of 586 women screened, vaginal and anorectal colonization was found in 21.7 and 24.4 per cent of them, respectively, concomitant vaginal and anorectal colonization was recorded in 16.5 per cent of the women studied. Serotypes III (33.2%), Ia (22.0%) and V (13.9%) prevailed among 172 isolates tested. All isolates were susceptible to penicillin, ampicillin and cefotaxime. The rates of GBS resistance to tetracycline, erythromycin and clindamycin were 83.9, 3.8 and 3.2 per cent, respectively. INTERPRETATION & CONCLUSION: GBS carriage in pregnant women in the Czech Republic is rather high as compared with that reported in literature. The most frequent serotypes III, Ia and V, identified in GBS-colonized pregnant women in the Czech Republic, were among those predominant in the USA and Western Europe. Our findings confirm uniform susceptibility of GBS isolates from pregnant women to penicillin and other beta-lactam antibiotics tested. Resistance to erythromycin remains low in the Czech Republic.

Predominance of serotype V and frequency of erythromycin resistance in Streptococcus agalactiae in Ohio.

OBJECTIVE: The purpose of this study was to test the serotype distribution and antibiotic sensitivity patterns of group B Streptococcus from three Ohio regions in comparison to other areas of the United States. STUDY DESIGN: Three hundred forty-nine group B Streptococcus isolates from three Ohio hospitals were serotyped specifically, and disk diffusion was used to determine antibiotic susceptibility. RESULTS: Serotype V was isolated most frequently (27%); major types Ia, Ib, II, and III had frequencies of 18%, 9%, 11%, and 17%, respectively. Erythromycin and clindamycin resistance was 12% (n = 200 isolates) and 8% (n = 49 isolates), respectively. CONCLUSION: The prevalence shift of resistant serotype V group B streptococci in Ohio reflects regional increases and suggests that alternative therapies for patients who are allergic to penicillin may be inadequate.

Rapid, colorimetric test for the determination of hippurate hydrolysis by group B Streptococcus.

A colorimetric test for the determination of hippurate hydrolysis was developed. Brain heart infusion broth made with 1% sodium hippurate served as the test medium. Hydrolysis was determined by the addition of two chemical developers, M (rhodamine B) and A (uranium acetate). A dark pink color indicated hydrolysis; no color change indicated no hydrolysis. The method was efficacious in either rapid or overnight incubation. One hundred twenty-five strains of group B, 44 strains of group A, 15 strains of group C, and 10 strains of group G Streptococcus were tested. By using the Lancefield method as the standard, there was 100% agreement with both the colorimetric and ferric chloride tests for hippurate hydrolysis, and 96% agreement with the CAMP test.