Molecular characterization, antimicrobial resistance and invasion of epithelial cells by Streptococcus agalactiae strains isolated from colonized pregnant women and newborns in Rio de Janeiro, Brazil.

AIMS: To evaluate the prevalence, molecular characteristics, antimicrobial susceptibility, and epithelial invasion of Streptococcus agalactiae strains isolated from pregnant women and newborns in Rio de Janeiro, Brazil. METHODS AND RESULTS: A total of 67 S. agalactiae isolates, 48 isolates from pregnant women and 19 from neonates, were analyzed. Capsular type Ia and V were predominant (35.8%/each). The multilocus sequence typing analysis revealed the presence of 19 STs grouped into 6 clonal complexes with prevalence of CC17/40.3% and CC23/34.3%. The lmb and iag virulence genes were found in 100% of isolates. Four S. agalactiae strains, belonging to CC17/ST1249 and CC23/ST23, were able to adhere to A549 respiratory epithelial cells. Antimicrobial resistance was verified mainly to tetracycline (85%), erythromycin (70.8%), and clindamycin (58.3%). Four S. agalactiae isolates were multidrug resistant. The resistance genes tested were found in 92.5% of isolates for tetM, 58.2% for ermB, 28.4% for mefAE, and 10.4% for tetO. CONCLUSION: The study showed a high prevalence of virulence and antimicrobial genes in S. agalactiae strains isolated from pregnant women and newborns, supporting the idea that continued surveillance is necessary to identify risk factors and perform long-term follow-up in pregnant women and neonates in Rio de Janeiro.

Ligilactobacillus salivarius V4II-90 eradicates Group B Streptococcus colonisation during pregnancy: a randomised, double-blind, placebo-controlled trial.

Group B Streptococcus (GBS) is the leading cause of bacterial neonatal sepsis. This study aimed to confirm the effect of Ligilactobacillus salivarius V4II-90 on GBS colonisation during pregnancy. A randomised, multicentre, double-blind, placebo-controlled, parallel-group study was conducted in seven hospitals in Madrid, Spain. The sample was broken down into two groups with 20 participants each (n = 40) in order to show reduced GBS colonisation frequency in the probiotic versus the placebo group. Pregnant participants positive for vaginal-rectal colonisation before or during the 13th week of gestation were randomly assigned to either the placebo or the probiotic group. The probiotic, L. salivarius V4II-90 at 1 × 109 cfu/day was administered for 12 weeks, starting at week 21-23 of gestation. The primary outcome was the percentage of participants with vaginal and/or rectal GBS colonisation at the end of the intervention period (35 weeks of gestation). Secondary outcomes were changes in the microbial composition of vaginal and rectal exudates; premature delivery; premature rupture of membranes; intrapartum antibiotics; new-borns with early or late-onset GBS sepsis; adverse events (AEs); and GBS test results performed at the hospital at week 35 of gestation. Of the 481 participants included, 44 were vaginal-rectal colonised with GBS and randomised. 43 completed the study (20 in the probiotic group and 23 in the placebo group). After intervention, GBS was eradicated in six participants (27%) from the placebo group and in twelve participants (63%) from the probiotic group ( P = 0.030). None of the 185 AEs reported were identified as possibly, probably, or definitely related to the investigational product. In conclusion, oral administration of L. salivarius V4II-90 is a safe and successful strategy to significantly decrease the rates of GBS colonisation at the end of pregnancy and, therefore, to reduce the exposure of subjects and their infants to intrapartum antibiotic prophylaxis. Trial registered at ClinicalTrials.gov: number NCT03669094.

Enrichment culture evaluation and characterization of Streptococcus agalactiae among pregnant women in Japan.

Introduction. Maternal screening tests and prophylactic antibiotics are important to prevent neonatal and infant group B streptococcal (GBS) infections.Hypothesis/Gap Statement. The performance of enrichment broth media for GBS screening that are available in Japan is unclear. Whole-genome data of GBS isolates from pregnant women in Japan is lacking.Aim. The aim of this study was to compare the protocol performance of six enrichment broths and two subculture agar plates, which were all available in Japan, for GBS detection. In addition, we showed whole-genome data of GBS isolates from pregnant women in Japan.Methodology. We collected 133 vaginal-rectal swabs from pregnant women visiting clinics and hospitals in Nagasaki Prefecture, Japan, and compared the protocol performance of 6 enrichment broths and 2 subculture agar plates. All GBS isolates collected in this study were subjected to whole-genome sequencing analysis.Results. We obtained 133 vaginal-rectal swabs from pregnant women at 35-37 weeks of gestation from 8 private clinics and 2 local municipal hospitals within Nagasaki Prefecture, Japan. The detection rate of the protocol involving the six enrichment broths and subsequent subcultures varied between 95.5 and 100 %, depending on the specific choice of enrichment broth. The GBS carriage rate among pregnant women in this region was 18.8 %. All 25 isolates derived from the swabs were susceptible to penicillin, whereas 48 and 36 % of the isolates demonstrated resistance to erythromycin and clindamycin, respectively. The distribution of serotypes was highly diverse, encompassing seven distinct serotypes among the isolates, with the predominant serotype being serotype V (n = 8). Serotype V isolates displayed a tendency towards increased resistance to erythromycin and clindamycin, with all resistant isolates containing the ermB gene.Conclusion. There was no difference in performance among the culture protocols evaluated in this study. GBS strains isolated from pregnant women appeared to have greater genomic diversity than GBS strains detected in neonates/infants with invasive GBS infections. To confirm this result, further studies with larger sample sizes are needed.

Trends in the antimicrobial susceptibility among Chinese neonates from 2012 to 2021: a multicenter study.

BACKGROUND: Antibiotic resistance is a serious global public health issue. However, there are few reports on trends in antimicrobial susceptibility in Chinese neonates, and most of the existing evidence has been derived from adult studies. We aimed to assess the trends in antimicrobial susceptibility of common pathogens in full-term neonates with invasive bacterial infections (IBIs) in China. METHODS: This cross-sectional survey study analyzed the antimicrobial susceptibility in Chinese neonates with IBIs from 17 hospitals, spanning from January 2012 to December 2021. Joinpoint regression model was applied to illustrate the trends and calculate the average annual percentage change (AAPC). Using Mantel-Haenszel linear-by-linear association chi-square test, we further compared the antibiotic minimum inhibitory concentrations (MICs) by pathogens between 2019 and 2021 to provide precise estimates of changes. RESULTS: The proportion of Escherichia coli with extended-spectrum-beta-lactamase-negative strains increased from 0.0 to 88.5% (AAPC = 62.4%, 95% confidence interval (CI): 44.3%, 82.9%), with two breakpoints in 2014 and 2018 (p-trend < 0.001). The susceptibility of group B Streptococcus (GBS) to erythromycin and clindamycin increased by 66.7% and 42.8%, respectively (AAPC = 55.2%, 95% CI: 23.2%, 95.5%, p-trend = 0.002; AAPC = 54.8%, 95% CI: 9.6%, 118.6%, p-trend < 0.001), as did Staphylococcus aureus to penicillin (AAPC = 56.2%; 95% CI: 34.8%, 81.0%, p-trend < 0.001). However, the susceptibility of Enterococcus spp. to ampicillin declined from 100.0 to 25.0% (AAPC = - 11.7%, 95% CI: - 15.2%, - 8.1%, p-trend < 0.001), and no significant improvement was observed in the antibiotic susceptibility of Escherichia coli to ampicillin, gentamicin, and cephalosporin. Additionally, the proportion of GBS/Staphylococcus aureus with relatively low MIC values for relevant antibiotics also increased in 2021 compared to 2019. CONCLUSIONS: Antimicrobial susceptibility of the most prevalent pathogens in full-term neonates seemed to have improved or remained stable over the last decade in China, implying the effectiveness of policies and practice of antibiotic stewardship had gradually emerged.

Loratadine Derivative Lo-7: A Weapon against Drug-Resistant Enterococcus and Streptococcal Infections.

The primary obstacles in the management of Enterococcus and Streptococcal infections are drug resistance and biofilm formation. Our study revealed that loratadine at a concentration of ≥25 µM exhibited significant inhibitory effects on biofilm formation in 167 clinical strains of Enterococcus faecalis and 15 clinical isolates of Streptococcus agalactiae, Streptococcus pyogenes, and Streptococcus pneumoniae. Additionally, the antibiofilm activity against E. faecalis and Streptococcal was demonstrated by several loratadine derivatives with altered side-chain carbamate moieties. This study investigated the antibacterial activity of the loratadine derivative Lo-7 against clinical strains of S. agalactiae and S. pyogenes, with minimum inhibitory concentrations ranging from 12.5 to 25 µM. The findings revealed that a low concentration of loratadine derivative Lo-7 (3.125 µM) significantly augmented the bactericidal efficacy of vancomycin against multidrug-resistant (MDR) S. agalactiae, both in vitro and in vivo. The loratadine derivative Lo-7, even at low concentrations, demonstrated significant efficacy in eliminating intracellular MDR S. agalactiae within macrophages, potentially indicating a unique advantage over vancomycin, linezolid, and loratadine. Mechanistically, exposure to the loratadine derivative Lo-7 resulted in membrane depolarization without affecting membrane permeability in S. agalactiae. The potential targeting of the SecG subunit of the SecYEG membrane-embedded channel by the loratadine derivative Lo-7 in S. agalactiae was identified through quantitative proteomics, a drug affinity responsive target stability assay, and molecular docking.

Analysis of Differences in Neonatal Sepsis Caused by Streptococcus Agalactiae and Escherichia Coli.

BACKGROUND: Streptococcus agalactiae (GBS) and Escherichia coli (E. coli) are the main pathogenic bacteria in neonatal sepsis. Therefore, the clinical characteristics, nonspecific indicators, and drug susceptibilities of these two bacteria were studied. METHODS: In total, 81 and 80 children with sepsis caused by GBS and E. coli infection, respectively, admitted to the neonatal department of our hospital between May 2012 and July 2023, were selected, and the clinical characteris-tics of the two groups were analyzed. Nonspecific indicators and drug sensitivity test results were analyzed retrospectively. RESULTS: Birth weight, tachypnea, groan, tachycardia or bradycardia, and the incidence of complications, such as pneumonia, respiratory failure, and purulent meningitis, were higher in the GBS group than in the E. coli group. The children were born prematurely, and the mother had a premature rupture of membranes. The incidence of jaundice, abdominal distension, atypical clinical manifestations, and complications of necrotizing enterocolitis was lower than of the E. coli group, and the differences were statistically significant (p < 0.05). The WBC, NE#, NE#/LY#, hs-CRP, and PCT of the GBS group were higher than those of the E. coli group, whereas the MPV, D-D, and FDP levels were lower than those in the E. coli group. The differences were all statistically significant (p < 0.05). The 81-bead GBS had high resistance rates against tetracycline (95%), erythromycin (48.8%), and clindamycin (40%), and no strains resistant to vancomycin, linezolid, penicillin, or ampicillin appeared, whereas 80 strains of E. coli were more resistant to penicillin and third-generation cephalosporins, with the higher resistance rates to ampicillin (68.30%), trimethoprim/sulfamethoxazole (53.6%), and ciprofloxacin (42.90%). Resistance rates to carbapenems and aminoglycosides were extremely low. CONCLUSIONS: Both GBS and E. coli neonatal sepsis have specific clinical characteristics, especially in terms of clinical manifestations, complications, non-specific indicators, and drug resistance. Early identification is important for clinical diagnosis and treatment.

[Molecular characteristics and drug susceptibility analysis of Streptococcus agalactiae from respiratory specimen sources].

To study the carriage status of drug susceptibility, clonal complex groups, serotypes, surface proteins and virulence genes of Streptococcus agalactiae from respiratory specimen sources. A total of 35 strains of S.agalactiae meeting the criteria were collected from 3 hospitals in 2 locations, Tangshan and Jinan. The age span of the patients was 3 days-92 years, and the percentage of elderly patients≥60 years was 71.5%.The susceptibility to 9 antimicrobial drugs was measured and analyzed using the micro broth dilution method. The strains were 100.0% sensitive to penicillin, linezolid, vancomycin, and ceftriaxone; However, it exhibits high resistance rates to erythromycin, clindamycin and levofloxacin, at 97.1%, 85.7% and 82.9% respectively; and the resistance rates to tetracycline and chloramphenicol were 34.3% and 14.2%, respectively. Genome sequence determination and analysis showed that 16 resistance genes were detected in 35 strains, among which: macrolide and lincosamide resistance genes were mainly ermB, with a carrying rate of 74.2%; tetracycline resistance genes were mainly tetM, with a carrying rate of 25.7%; in addition, the mutation rates of the quinolone resistance determinants gyrA and parC were 88.5% and 85.7%, respectively. 35 strains belonged to 6 ST types and 4 clonal groups, with CC10/ST10 as the main one, accounting for 62.8%; they contained 4 serotypes of Ⅰb, Ⅱ, Ⅲ, and Ⅴ, as well as 1 untyped strain, with serotype Ⅰb as the main one, accounting for 65.7%. The strains carried three pilus types, PI1+PI2a, PI2a and PI2b types, respectively, and detected five surface proteins, alpha, alp1, rib, srr, and rdf_0594, and seven virulence factors, cba, cfb, cylE, fbsA, hylB, lmb, and pavA. Overall, S.agalactiae isolated from respiratory tract specimens is predominantly sourced from elderly patients, with CC10 strains being most prevalent. These strains harbor multiple drug-resistant and virulence genes, demonstrating elevated resistance rates to macrolides, lincosamides, and quinolones. This emphasizes the necessity for vigilant attention to the health threat posed by S. agalactiae from respiratory tract speciments of elderly patients.

Copaiba oil's bactericidal activity and its effects on health and zootechnical performance for Nile tilapia after oral supplementation.

Tilapia is one of the most important farmed fish in the world and the most cultivated in Brazil. The increase of this farming favors the appearance of diseases, including bacterial diseases. Therefore, the aim of this study was to evaluate the bactericidal activity of copaiba oil, Copaifera duckei, against Streptococcus agalactiae and Flavobacterium columnare and the dietary effect of copaiba oil on zootechnical performance, hematological, biochemical, immunological, and histological analysis before and after an intraperitoneal infection (body cavity) with S. agalactiae in Nile tilapia. For this, fish were randomly distributed into 15 fiber tanks in five treatments (0, 0.25, 0.50, 0.75, and 1.0%) and fed with a commercial diet supplemented with copaiba oil for 30 days. After this period, the fish were randomly redistributed for the experimental challenge with S. agalactiae into six treatments (T0, T1, T2, T3, T4, and T5), the fish were anesthetized, and blood samples were collected to assess hematological, biochemical, immunological, and histological parameters. Copaiba oil showed bactericidal activity against Streptococcus spp. and Flavobacterium spp. in vitro. In addition, concentrations of 0.75 and 1.0% of copaiba oil have an anti-inflammatory effect and improve hematological and immunological parameters, increasing leukocyte numbers, albumin, and serum lytic activity. Furthermore, there is an increase in the intestinal villus length and tissue damage in groups at concentrations of 0.75 and 1.0% of copaiba oil. In conclusion, copaiba oil presented bactericidal activity against Streptococcus spp. and Flavobacterium spp. in vitro, and oral supplementation at concentrations of 0.75 and 1.0% compared to the control group enhanced non-specific immune parameters and digestibility in Nile Tilapia.

Identification of antibiotic induced persister cells in Streptococcus agalactiae.

Antibiotic persistence is a phenomenon, where a small fraction of a bacterial population expresses a phenotypic variation that allows them to survive antibiotic treatment, which is lethal to the rest of the population. These cells are called persisters cells, and their occurrence has been associated with recurrent disease. Streptococcus agalactiae is a human pathobiont, able to cause invasive infections, and recurrent infections have been reported to occur in both newborns and adults. In this study, we demonstrated that S. agalactiae NEM316 can form persister cells when exposed to antibiotics from different classes. The frequency of persister cell formation was dependent on bacterial growth phase and the class of antibiotics. The ability to form persister cells in response to penicillin was shown to be a general trait among different clinical S. agalactiae isolates, independent of sero- and sequence-type. Taken together, this study shows the existence of antibiotic tolerant S. agalactiae persister cells, which may explain why this bacterial species frequently persists after treatment of invasive infection and can be associated with recurrent disease.

Ice nucleation active bacteria metabolites as antibiofilm agent to control Aeromonas hydrophila and Streptococcus agalactiae infections in Aquaculture.

OBJECTIVES: The aim of this study was to quantify and identify metabolites of Ice Nucleation Active (INA) bacteria as an anti-biofilm agent against biofilms of fish pathogens such as Aeromonas hydrophila and Streptococcus agalactiae. RESULTS: Ice nucleation active bacteria, which have the ability to catalyze ice nucleation, isolated from rainwater in previous studies, were used. All INA isolates were tested in several assays, including the antimicrobial test, which uses streptomycin as the positive control and none of the isolates were found positive in the antimicrobial test. As for the quorum quenching assay, it was found that four out of ten isolates were able to disturb the communication system in Chromobacterium violaceum wild type, which was used as the indicator bacteria. On the next assay, all ten isolates were tested for Biofilm Inhibition and Destruction and showed anti-biofilm activity with the highest percentage inhibition of 33.49% by isolate A40 against A. hydrophila and 77.26% by isolate A19 against S. agalactiae. C1 performed the highest destruction against A. hydrophila and S. agalactiae, with percentages of 32.11% and 51.88%, respectively. As for the GC-MS analysis, supernatants of INA bacteria contain bioactive compounds such as sarcosine and fatty acids, which are known to have antibiofilm activity against several biofilm-forming bacteria. Through 16s rRNA sequencing, identified bacteria are from the Pantoea, Enterobacter, and Acinetobacter genera. As for the conclusion, ice nucleation active bacteria metabolites tested showed positive results against pathogenic bacteria Aeromonas hydrophila and Streptococcus agalactiae in destructing and inhibiting biofilm growth.

Genomic insights into the diversity, virulence, and antimicrobial resistance of group B Streptococcus clinical isolates from Saudi Arabia.

Introduction: Detailed assessment of the population structure of group B Streptococcus (GBS) among adults is still lacking in Saudi Arabia. Here we characterized a representative collection of isolates from colonized and infected adults. Methods: GBS isolates (n=89) were sequenced by Illumina and screened for virulence and antimicrobial resistance determinants. Genetic diversity was assessed by single nucleotide polymorphisms and core-genome MLST analyses. Results: Genome sequences revealed 28 sequence types (STs) and nine distinct serotypes, including uncommon serotypes VII and VIII. Majority of these STs (n=76) belonged to the human-associated clonal complexes (CCs) CC1 (33.71%), CC19 (25.84%), CC17 (11.24%), CC10/CC12 (7.87%), and CC452 (6.74%). Major CCs exhibited intra-lineage serotype diversity, except for the hypervirulent CC17, which exclusively expressed serotype III. Virulence profiling revealed that nearly all isolates (94.38%) carried at least one of the four alpha family protein genes (i.e., alphaC, alp1, alp2/3, and rib), and 92.13% expressed one of the two serine-rich repeat surface proteins Srr1 or Srr2. In addition, most isolates harbored the pilus island (PI)-2a alone (15.73%) or in combination with PI-1 (62.92%), and those carrying PI-2b alone (10.11%) belonged to CC17. Phylogenetic analysis grouped the sequenced isolates according to CCs and further subdivided them along with their serotypes. Overall, isolates across all CC1 phylogenetic clusters expressed Srr1 and carried the PI-1 and PI-2a loci, but differed in genes encoding the alpha-like proteins. CC19 clusters were dominated by the III/rib/srr1/PI-1+PI-2a (43.48%, 10/23) and V/alp1/srr1/PI-1+PI-2a (34.78%, 8/23) lineages, whereas most CC17 isolates (90%, 9/10) had the same III/rib/srr2/P1-2b genetic background. Interestingly, genes encoding the CC17-specific adhesins HvgA and Srr2 were detected in phylogenetically distant isolates belonging to ST1212, suggesting that other highly virulent strains might be circulating within the species. Resistance to macrolides and/or lincosamides across all major CCs (n=48) was associated with the acquisition of erm(B) (62.5%, 30/48), erm(A) (27.1%, 13/48), lsa(C) (8.3%, 4/48), and mef(A) (2.1%, 1/48) genes, whereas resistance to tetracycline was mainly mediated by presence of tet(M) (64.18%, 43/67) and tet(O) (20.9%, 14/67) alone or in combination (13.43%, 9/67). Discussion: These findings underscore the necessity for more rigorous characterization of GBS isolates causing infections.

Chlorella vulgaris algae ameliorates chlorpyrifos toxicity in Nile tilapia with special reference to antioxidant enzymes and Streptococcus agalactiae infection.

BACKGROUND: Chlorpyrifos (CPF) is a widely used pesticide in the production of plant crops. Despite rapid CPF biodegradation, fish were exposed to wastewater containing detectable residues. Recently, medicinal plants and algae were intensively used in aquaculture to replace antibiotics and ameliorate stress impacts. METHODS AND RESULTS: An indoor experiment was conducted to evaluate the deleterious impacts of CPF pollution on Nile tilapia health and the potential mitigation role of Chlorella vulgaris algae. Firstly, the median lethal concentration LC50 - 72 h of CPF was determined to be 85.8 µg /L in Nile tilapia (35.6 ± 0.5 g body weight) at a water temperature of 27.5 °C. Secondly, fish were exposed to 10% of LC50 - 72 h for six weeks, and tissue samples were collected and examined every two weeks. Also, Nile tilapia were experimentally infected with Streptococcus agalactiae. Exposed fish were immunosuppressed expressed with a decrease in gene expressions of interleukin (IL) 1ß, IL-10, and tumor necrosis factor (TNF)-α. Also, a decline was recorded in glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT) gene expression in the head kidney tissue. A high mortality rate (MR) of 100% was recorded in fish exposed to CPF for six weeks and challenged with S. agalactiae. Fish that received dietary C. vulgaris could restore gene expression cytokines and antioxidants compared to the control. After six weeks of CPF exposure, fish suffered from anemia as red blood cell count (RBCs), hemoglobin (Hb), and packed cell volume (PCV) significantly declined along with downregulation of serum total protein (TP), globulin (GLO), and albumin (ALB). Liver enzymes were significantly upregulated in fish exposed to CPF pollution, alanine aminotransferase (ALT) (42.5, 53.3, and 61.7 IU/L) and aspartate aminotransferase (AST) (30.1, 31.2, and 22.8) after 2, 4, and 6 weeks, respectively. On S. agalactiae challenge, high MR was recorded in Nile tilapia exposed to CPF (G3) 60%, 60%, and 100% in week 2, week 4, and week 6, and C. vulgaris provided a relative protection level (RPL) of 0, 14.29, and 20%, respectively. CONCLUSIONS: It was concluded that CPF pollution induces immunosuppressed status, oxidative stress, and anemic signs in Nile tilapia. In contrast, C. vulgaris at a 50 g/kg fish feed dose could partially ameliorate such withdrawals, restoring normal physiological parameters.

Distributions of candidate vaccine Targets, virulence Factors, and resistance features of invasive group B Streptococcus using Whole-Genome Sequencing: A Multicenter, population-based surveillance study.

BACKGROUND: Group B Streptococcus (GBS) is a leading cause of morbidity and mortality in young infants worldwide. This study aimed to investigate candidate GBS vaccine targets, virulence factors, and antimicrobial resistance determinants. METHODS: We used whole-genome sequencing to characterize invasive GBS isolates from infants < 3 months of age obtained from a multicenter population-based study conducted from 2015 to 2021 in China. RESULTS: Overall, seven serotypes were detected from 278 GBS isolates, four (Ia, Ib, III, V) of which accounted for 97.8 %. We detected 30 sequence types (including 10 novel types) that were grouped into six clonal complexes (CCs: CC1, CC10, CC17, CC19, CC23 and CC651); three novel ST groups in CC17 were detected, and the rate of CC17, considered a hyperinvasive neonatal clone complex, was attached to 40.6 % (113/278). A total of 98.9 % (275/278) of isolates harbored at least one alpha-like protein gene. All GBS isolates contained at least one of three pilus backbone determinants and the pilus types PI-2b and PI-1 + PI-2a accounted for 79.8 % of the isolates. The 112 serotype III/CC17 GBS isolates were all positive for hvgA. Most of the isolates (75.2 %) were positive for serine-rich repeat glycoprotein determinants (srr1or srr2). Almost all isolates possessed cfb (99.6 %), c1IE (100 %), lmb (95.3 %) or pavA (100 %) gene. Seventy-seven percent of isolates harboured more than three antimicrobial resistance genes with 28.4 % (79/278) gyrA quinoloneresistancedeterminants mutation, 83.8 % (233/278) carrying tet cluster genes and 77.3 % (215/278) carrying erm genes which mediated fluoroquinolone, tetracycline and clindamycin resistance, respectively." CONCLUSIONS: The findings from this large whole-genome sequence of GBS isolates establish important baseline data required for further surveillance and evaluating the impact of future vaccine candidates.

Emergence of Group B Streptococcus Disease in Pigs and Porcupines, Italy.

We describe group B Streptococcus linked to disease in farmed pigs and wild porcupines in Italy. Occurrence in pigs was attributed to transmission from nonpasteurized bovine milk whey. Antimicrobial-resistance profiles in isolates from porcupines suggest no common source of infection. Our findings expand the known host range for group B Streptococcus disease.

Macrolide resistance among Streptococcus agalactiae during COVID-19 public health emergency in Brazil.

During COVID-19 public health emergence, azithromycin was excessively used in Brazil, as part of a controversial "early treatment", recommended by former national health authorities. Excessive usage of macrolides may increase resistance rates among beta-hemolytic streptococci. Therefore, this study aimed to investigate the occurrence of resistance to erythromycin and clindamycin among Streptococcus agalactiae recovered from February 2020 to May 2023. Bacterial isolates (n = 116) were obtained from pregnant women and submitted to antimicrobial susceptibility testing, investigation of macrolide resistance phenotypes and genotypes, and identification of capsular type. The overall rate of erythromycin not susceptible (NS) isolates was 25.9%, while resistance to clindamycin was 5.2%. Drug efflux, associated with the M phenotype and mef(A) gene, was the prevalent mechanism of resistance (80%). Capsular type Ia was predominant (39.8%), followed by II, III, and V (17.7% each). A higher diversity of types was observed in the last years of the study. Type IV has had an increasing trend over time, being the fourth most common in 2023. The majority of the isolates that expressed the M phenotype presented capsular type Ia, while those with iMLS phenotype presented capsular type V. Despite no causal relationship can be established, azithromycin excessive usage may be a possible factor associated with this higher rate of erythromycin NS isolates, compared with most previous national studies. On the other hand, resistance to clindamycin has not changed significantly. Therefore, in the studied clinical setting, clindamycin remains a useful alternative to intrapartum prophylaxis among penicillin-allergic pregnant women.

Characterization of Lactococcus garvieae and Streptococcus agalactiae in cultured red tilapia Oreochromis sp. in Thailand.

OBJECTIVE: Acute mortality with clinical symptoms of streptococcal-like infections was observed in red tilapia Oreochromis sp. cultured in floating cages in Prachin Buri Province, Thailand, during May 2023. Herein, we identified an emerging pathogen, Lactococcus garvieae, as the etiological agent. METHODS: After bacterial isolation from the brain and kidney of diseased fish, identification was performed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and the VITEK 2 system. Sequencing of the 16S ribosomal RNA (rRNA) gene and phylogenetic analysis were applied to confirm bacterial species. Antimicrobial susceptibility testing was conducted. Histopathological findings in the brain, kidney, spleen, liver, and heart were evaluated. RESULT: From 20 fish samples, L. garvieae (n = 18 isolates) and Streptococcus agalactiae (n = 2 isolates) were identified. A phylogenetic tree of the 16S rRNA gene revealed that Thai isolates of either L. garvieae or S. agalactiae clustered with reference piscine isolates from intercontinental locations. Our isolates showed resistance against quinolones while being susceptible to other antimicrobials. Histopathological changes demonstrated severe septicemic conditions, with more invasive lesions-especially in the heart and liver-being apparent in L. garvieae-infected fish compared to S. agalactiae-infected fish. CONCLUSION: This study represents the first reported outbreak of L. garvieae with a concurrent S. agalactiae infection in farmed red tilapia in Thailand.

Serotype distribution, virulence and antibiotic resistance of Streptococcus agalactiae isolated from cultured tilapia Oreochromis niloticus in Lake Volta, Ghana.

Streptococcus agalactiae infection is one of the major factors limiting the expansion of tilapia farming globally. In this study, we investigated the serotype distribution, virulence and antimicrobial resistance of S. agalactiae isolates from tilapia farmed in Lake Volta, Ghana. Isolates from 300 moribund fish were characterised by Gram staining, MALDI-TOF/MS and 16S rRNA sequencing. Serotype identification was based on multiplex polymerase chain reaction (PCR) amplification of the capsular polysaccharide genes. Detection of virulence genes (cfb, fbsA and cspA) and histopathology were used to infer the pathogenicity of the isolates. The susceptibility of isolates to antibiotics was tested using the Kirby-Bauer disk diffusion assay. All 32 isolates identified as S. agalactiae were of serotype Ia. This was notably different from isolates previously collected from the farms in 2017, which belonged to serotype Ib, suggesting a possible serotype replacement. The prevalence of the pathogen was related to the scale of farm operation, with large-scale farms showing higher S. agalactiae positivity. Data from histopathological analysis and PCR amplification of targeted virulence genes confirmed the virulence potential and ability of the isolates to cause systemic infection in tilapia. Except for gentamicin, the majority of the isolates were less resistant to the tested antibiotics. All isolates were fully sensitive to oxytetracycline, erythromycin, florfenicol, enrofloxacin, ampicillin and amoxicillin. This study has improved our understanding of the specific S. agalactiae serotypes circulating in Lake Volta and demonstrates the need for continuous monitoring to guide the use of antimicrobials and vaccines against streptococcal infections in Ghanaian aquaculture systems.

A decade of neonatal sepsis in Stockholm, Sweden: Gram-positive pathogens were four times as common as Gram-negatives.

PURPOSE: To assess Gram-positive bacterial (GPB) bloodstream infection (BSI) in neonates, covering incidence, morbidity, mortality, antimicrobial resistance patterns and biomarkers in Region Stockholm, Sweden between 2006 and 2016. METHODS: A population-based retrospective epidemiological study including infants with GPB-BSI, admitted to the neonatal units at Karolinska University Hospital (KUH). Data were collected from patient records, the Swedish Neonatal Quality Register, the microbiological laboratory at KUH and the Swedish Public Health Agency. RESULTS: We identified 357 infants with GPB-BSI, representing an incidence of 1.47/1000 live births (LB). Group B streptococcus (GBS) was the most common pathogen causing BSI in full-term infants and early-onset sepsis (EOS) (0.20/1000 LB), while coagulase-negative staphylococci (CoNS) were predominant in infants born very preterm and in late-onset sepsis (LOS) (0.79/1000 LB). There were no fatal GBS BSI cases, but 10.2% developed meningitis. The GPB case fatality rate was 9.5% and the sepsis fatality rate 2.8%. In GPB-BSI, 1/10 did not have an elevated C-reactive protein level. Staphylococcus aureus (S. aureus) BSI increased during the study period, but no methicillin or vancomycin resistant strains were found. The antimicrobial resistance (AMR) rate was highest in CoNS isolates. CONCLUSION: GPB-BSI was four times more common than Gram-negative BSI in neonates but resulted in lower mortality rate. GBS was the most common pathogen in full-term infants and in EOS. CoNS was the most common pathogen in LOS and infants born very preterm, and the AMR rate was high in these isolates. The increasing trend of S. aureus BSI indicates a need of further investigation.

Group B streptococcus in the Northern Territory in 2023: clindamycin down but not out.

Group B streptococcus (GBS) is a significant cause of perinatal morbidity and mortality; prophylactic antibiotics in the obstetric population can mitigate the risk of neonatal infection. The antibiotic of choice is penicillin; however, in women who have a penicillin hypersensitivity, clindamycin is the preferred agent. Worldwide resistance to clindamycin is rising in GBS isolates. In the Top End of the Northern Territory of Australia, we reviewed 113 GBS isolates in 2023. These GBS isolates revealed a 30% resistance to clindamycin. This rate has considerably increased since the Australia-wide survey published in 2011 where GBS resistance to clindamycin was quoted at 4.2%. As a result of this study, we are advocating for a change in practice in patients with known GBS resistance with penicillin hypersensitivity.

Antibacterial and anti-trichomunas characteristics of local landraces of Lawsonia inermis L.

BACKGROUND: Henna (Lawsonia inermis) with anti-bacterial properties has been widely used in traditional medicine especially Persian medicine. Henna oil is suggested for diseases of infectious origin, such as cervical ulcers. Group B Streptococcus agalactiae, Pseudomonas aeruginosa and, Trichomonas vaginalis are involved in the infection of women especially cervicitis. Henna grows in dry and tropical regions. The main important landraces of henna landraces are cultivated in Kerman, Sistan and Baluchestan, Hormozgan, and Bushehr provinces in Iran. Proper use of antimicrobial agents, use of new antimicrobial strategies, and alternative methods, such as herbal methods may help reduce drug resistance in the future. This study's objective was to investigate the anti-Trichomonas vaginalis activity of three different henna landraces and antimicrobial effects against group B Streptococcus agalactiae and, Pseudomonas aeruginosa. METHODS: Total phenol content was measured by Folin ciocaltu method. Antibacterial effect of landraces of Henna against P. aeruginosa and S. agalactiae were assayed by well diffusion method and minimal inhibitory concentration assessments were done using the broth micro-dilution technique. Anti-Trichomonas effect of Henna landraces were assayed by Hemocytometery method. RESULTS: Total phenol content of Shahdad, Rudbar-e-Jonub, and Qaleh Ganj was 206.51, 201.96, and 254.85 µg/ml, respectively. Shahdad, Rudbar-e-Jonub, and Qaleh Ganj had MIC against GBS at 15, 15 and, 4 µg/ml. The growth inhibition diameter of the most effective henna (Shahdad landrace) at a concentration of 20 µg/ml on P. aeruginosa was 2.46 ± 0.15 cm and in the MIC method at a concentration of 5 µg/ml of Shahdad landrace, P. aeruginosa did not grow. IC50 of shahdad Henna after 24 h, 48 h, and 72 h was 7.54, 4.83 and 20.54 µg/ml, respectively. IC50 of Rudbar-e-Jonub extract was 5.76, 3.79 and 5.77 µg/ml in different days. IC50 of Qaleh Ganj extract was 6.09, 4.08 and 5.74 µg/ml in different days. CONCLUSIONS: The amount of total phenol in Qaleh Ganj was higher than the other varieties. In the well diffusion method, Qaleh Ganj was more effective against group B Streptococcus (Gram-positive bacterium) than the other two landraces, and Shahdad landrace was more effective against P. aeruginosa (Gram-negative bacterium) than other. In the MIC method, the same result was obtained as in the well diffusion method, but at a lower concentration.