Antibacterial Activity of Herbal Preparations against Staphylococcus aureus and Streptococcus agalactiae in Cow Mastitis

[Objective] This study aimed to analyze the antibacterial activity of herbal preparations against Staphylococcus aureus and Streptococcus agalactiae in cow mastitis. [Method] The crude drug solutions of four different prescriptions for Zengrujianniusan were prepared through reflux extraction. Their antibacterial activity in vitro against Staphylococcus aureus and Streptococcus agalactiae in cow mastitis were investigated. [Result] All the four different prescriptions exhibited antibacterial activity against S. aureus and S. agalactiae. Among them, prescription Ⅲ was extremely sensitive, and had the best bactericidal effect. The other three prescriptions were highly sensitive. [Conclusion] This study provides a theoretical basis for the development of herbal preparations for the treatment of cow mastitis.

Trend of Invasive Streptococcus agalactiae at Tertiary Care Hospital in Japan

Streptococcus agalactiae causes various severe infectious diseases such as sepsis, meningitis, and streptococcal toxic shock-like syndrome. Though Streptococcus agalactiae infection has been increasing recently, the comprehensive characteristic investigation of invasive Streptococcus agalactiae isolated in tertiary care hospitals has not been nearly performed in Japan. In this study, we investigated the clinical characteristics and antimicrobial susceptible patterns of 88 Streptococcus agalactiae isolated at two tertiary care hospitals during 2009-2015 in Japan. There was no significant differences between genders in our study. Two-third Streptococcus agalactiae were isolated from over age 60. Total mortality rate was 19% and invasive Streptococcus agalactiae-associated death cases have occurred every year after 2011. All Streptococcus agalactiae were completely susceptible toampicillin. Total non-susceptible rates of erythromycin, minocycline, levofloxacin and trimethoprim-sulfamethoxazole in this study were approximately 30%, 44%, 37%, and 7%, respectively. Our results suggest the need for continuous antimicrobial susceptibility survey of Streptococcus agalactiae.

Streptococcus agalactiae:Identification methods,antimicrobial susceptibility, and resistance genes in pregnant women

BACKGROUND Group B Streptococcus(GBS)is a normal component of the gastrointestinal and genital microbiota in humans and can lead to important infections in newborns.AIM To compare GBS isolation and identification methods as well as to assess the antibiotic susceptibility and to identify resistance genes in GBS strains from pregnant women attended in healthcare services from the city of Vitória da Conquista,in Bahia State,Brazil.METHODS From January 2017 to February 2018,vaginorectal swabs were obtained from 186 participants and the samples were seeded onto chromogenic agar for GBS before and after inoculation in selective broth.Confirmatory identification using 3 CAMP and latex tests was performed in samples with GBS-suggestive colonies.Then,disk diffusion antibiograms were performed in GBS-positive samples,and the detection of the resistance genes ermB,ermTR,mefA,and linB in the clindamycin and/or erythromycin-resistant samples was carried out.RESULTS Thirty-two samples(17.2%)were GBS-positive.The culture in chromogenic agar after sample incubation in selective broth was the most sensitive method(96.9%)for GBS detection.All isolates were susceptible to penicillin,ampicillin,cefotaxime,and vancomycin.Clindamycin resistance was observed in 6 samples(18.8%),while 8 samples(25%)were erythromycin-resistant.All erythromycin and/or clindamycin-resistant GBS strains had negative D-tests.Two strains(25%)presented an M phenotype and 6 isolates(75%)presented a cMLSB phenotype.The ermB gene was identified in 4 samples(44.4%),the mefA gene was also found in 4 samples(44.4%),the ermTR gene was identified in 1 isolate(11.1%),and the linB gene was not found in any isolate.CONCLUSION This study evidenced that the screening for SGB can be performed by means of various methods,including chromogenic media,and that the chemoprophylaxis for pregnant women who cannot use penicillin must be susceptibility-guided.

In vitro Antibacterial Activity of Palmitoleic Acid Isolated from Filamentous Microalga Tribonema minus Against Fish Pathogen Streptococcus agalactiae

Filamentous microalgae from genus Tribonema are promising sustainable sources of omega-7 palmitoleic acid,but their ability to accumulate this compound varies among species and depends on the initial nitrogen concentration(INC)supply.In this study,the palmitoleic acid accumulation capacities of five Tribonema species were examined under three different INCs to select the alga species with the highest production.Results showed that a high INC was associated with increased palmitoleic acid accumulation but led to decreased biomass concentration in all tested species.In particular,T.minus grown at 18 mmol L^(−1)INC had the highest palmitoleic acid content(20.72%of dry weight)and productivity(90.88 mg L^(−1)d−1).The combination of alkali metal freezing precipitation(AMFP)and urea complexation successfully isolated and enriched palmitoleic acid from T.minus and obtained a purity of 80.11%and a yield of 7.39 g(100 g)^(−1) of algal powder.The compound was identified as(9Z)-hexadecenoic acid(C16:1ω-7).Antibacterial activity evaluation for the highly concentrated palmitoleic acid(10 mg mL^(−1))against Streptococcus agalactiae revealed the formation of a 12.10 mm-diameter inhibition zone and the minimum inhibitory concentration of 31.25μg mL^(−1),indicating that palmitoleic acid is an effective antibacterial agent.This study is the first to report that palmitoleic acid derived from T.minus can antagonize S.agalactiae,which further broadens the potential application of Tribonema biomass in green aquaculture.

The Streptococcus agalactiae Ribose Binding Protein B (RbsB) Mediates Quorum Sensing Signal Uptake via Interaction with Autoinducer-2 Signals

Understanding aquatic pathogen in sediments or aquacultural water is crucial to protect public health from soilborne and waterborne diseases.Quorum sensing(QS)was increasingly reported in biological wastewater treatment processes because of their inherent roles in biofilm development,bacterial aggregation and so on.The widely QS signals was Antoinducer-2(AI-2),primarily involved to allow the possibility of interspecies communication.However,the cellular components that mediate the response of Streptococcus agalactiae to AI-2 have not been fully characterized.Analysis of the complete genome sequence of S.agalactiae indi-cated that its RbsB protein has similarity to Escherichia coli LsrB and Aggregatibacter actinomycetemcomitans RbsB proteins that bind AI-2.We hypothesized that RbsB protein mediates quorum sensing signal uptake via interaction with AI-2.To evaluate the regulatory effect of RbsB on QS system,the recombinant plasmid pGEX-6p-1-RbsB was constructed and RbsB protein was purified with GST-tag.To further elucidate the role of RbsB protein binding to DPD(AI-2 precursor dihydroxypentanedione),the systemati-cally throughput circular dichroism(CD)spectroscopy,isothermal titration calorimetry200(ITC200)and molecular docking methods were employed.The high expression of soluble RbsB protein with molecular weight of 33 kDa was obtained.The thermodynamics results(ΔH<0,ΔS<0,ΔG<0)with ITC determination indicated that the binding process between DPD and RbsB was exothermic and spontaneous,with hydrogen bonds and van der Waals forces as the main binding forces.Obviously,DPD can be more easily combined with RbsB in a dose-dependent manner,suggesting that RbsB was changed in the microenvironment of DPD when the DPD concentration was between 0.8-1.0mmolL−1 and reaching the maximum binding amount.According to molecular docking,3 hydrophobic residues involved in DPD and RbsB protein stable binding were be found,and also hydrogen bonding plays a key role in the formation of the new complex.RbsB efficiently inhibited V.harveyi bioluminescence induced by both S.agalactiae AI-2 and V.harveyi AI-2 in a dose-dependent manner.However,our results suggest that RbsB may play a role in the response of S.agalactiace to AI-2.

PCR Detection of Streptococcus agalactiae in Dairy Cows Suffering from Mastitis

[ Objective ] This study aimed to identify Streptococcus agalactiae and lay the foundation for the prevention and control of mastiffs in dairy cows. [ Method] Ten strains were isolated from milk samples produced by diseased dairy cows suffering from mastitis for morphologic observation, culture characteristic investigation, biochemical identification and Lancefield grouping. The isolated strains were identified at the molecular level by nested-PCR. [ Result] Among the ten isolates, six strains were 13-hemolytic and Gram-positive on blood agar, belonging to Lancefield group B, which were identified as Streptococcus agalactiae by biochemical identification and nested-PCR. After overnight incubation, the coincidence rate between results of nested-PCR detection and biochemical identification reached 100%. [ Conclusion ] Bacterial incubation, rapid DNA extraction and specific PCR can provide basis for early epidemiological survey of Streptococcus agalactiae infection in cattle.

Streptococcus agalactiae:Sensitivity profile in pregnant women attending health units in northeastern Brazil

BACKGROUNDG roup B Streptococcus agalactiae (GBS) is the main etiologic agent associated withearly-onset neonatal sepsis, and of all newborns of parturients colonized by GBS,approximately 1%-2% develop invasive, early-onset disease. The risk of infectionincreases to 15.2% in premature neonates, to 10.7% when the parturient haschorioamnionitis or premature rupture of membranes for more than 24 h and to9.7% if the mother has postpartum bacteremia. In addition to causing perinatal,neonatal and postnatal deaths, neonatal hospital infection is associated with highcosts, as hospitalization is three times longer than in uninfected children. Theidentification of pregnant women colonized by GBS, through universal screening,associated with the adoption of appropriate antibiotics at the time of delivery arethe most successful preventive measures.AIMTo evaluate the sensitivity profile of GBS isolated from pregnant womenattending Vitória da Conquista-BA.METHODS This is a cross-sectional study with a quantitative approach carried out in themunicipality of Vitória da Conquista-Bahia between February 2017 and March2018. The study population was composed of 210 pregnant women, with agestational age of 32 to 40 wk, who were aged 18 years or older living in the urbanarea of the municipality of Vitória da Conquista. After a brief explanation aboutthe research and obtaining a signed an informed consent form, data andvaginorectal swabs were collected from the women for GBS research. Examinationof the samples in order to identify the presence of GBS was by culture on sheep blood agar and chromogenic agar for GBS and then, seeded on plates containingstreptococcal culture medium and incubated for 18 h to 24 h at 35°C. Theantimicrobial sensitivity profile of positive GBS samples was determined by thedisk diffusion technique, according to the Clinical and Laboratory StandardsInstitute manual (2017). The data obtained were stored in a database usingMicrosoft Office Excel spreadsheets and a descriptive analysis was performedwith the aid of the EPI-INFO statistical package (version 3.5.2).RESULTSAmong the 210 pregnant women participating in the study, 38 (18.1%) had apositive GBS culture. All strains isolated from GBS were sensitive to 10 Upenicillin, 10 μg ampicillin, 30 μg cefotaxime and 30 μg vancomycin. Seven strains(18.4%) resistant to clindamycin 2 μg and eight (21.1%) resistant to erythromycin15 μg were found. Of these, six were concomitantly resistant to erythromycin andclindamycin, two resistant only to erythromycin and one resistant only toclindamycin. All nine GBS isolates that showed resistance to erythromycin and/orclindamycin showed negative results on the D-test. Two thirds of the isolatesshowed cMLSB phenotype and resistance only to erythromycin in specimens inthis study (02), refers to strains with phenotype M and resistance to clindamycin(01) only with phenotype L.CONCLUSIONChemoprophylaxis for GBS in pregnant women, especially for those allergic topenicillin, should be guided by an antimicrobial susceptibility test as resistantGBS strains were reported in this study.

A Pathological Study of GIFT Strain of Nile Tilapia(Oreochromis niloticus)Infected by Streptococcus agalactiae

[Objectives] This study aimed to determine the infection pathway and target organs of Streptococcus agalactiae in GIFT strain of Nile tilapia, thus providing theoretical basis for the breeding of disease-resistant tilapia and development of S. agalactiae vaccines.[Methods] GIFT strain of Nile tilapia was inoculated by S. agalactiae through intraperitoneal injection, oral gavage and in vitro immersion. The gill, spleen, liver and small intestine tissues of infected tilapia were collected for pathomorphological observation. Immunohistochemical localization was conducted using rabbit anti- S. agalactiae serum to identify the distribution pattern of S. agalactiae in various tissues of tilapia and its target organs via different infection pathways.[Results] GIFT strain of Nile tilapia could be infected by S. agalactiae via three artificial inoculation modes. Specifically, pathological changes occurred at 2 h post-inoculation in intraperitoneal injection and oral gavage groups, whereas tilapia in in vitro immersion group showed pathological changes at 5 h post-inoculation, and the lesion intensity in in vitro immersion group was slighter than that in intraperitoneal injection and oral gavage groups. Immunohistochemical localization indicated that the appearance time of positive signals in intraperitoneal injection group demonstrated an order of spleen→liver and gill→small intestine; positive signals in oral gavage group appeared in the order of small intestine→gill and spleen→liver; the appearance time of positive signals in in vitro immersion group showed an order of gill→spleen→liver and small intestine.[Conclusions] GIFT strain of Nile tilapia could be infected by S. agalactiae via intraperitoneal injection, oral gavage and in vitro immersion. The corresponding positive signals for pathogen infection were preferentially present in the spleen, intestine and gill tissues. Thus, preventing S. agalactiae contamination in aquaculture water and food sources is an effective measure to control the outbreak of S. agalactiae infections in tilapia under natural aquaculture conditions.

Epidemiological observations of invasive group B Streptococcus infections in six major hospitals in Peninsular Malaysia

Objective:To address the lack of research on invasive group B Streptococcus(GBS)infections in Malaysia and Southeast Asia through a comprehensive analysis of GBS isolates obtained from hospitals.Methods:Medical records from patients with GBS infection isolated from the sterile site,such as blood and cerebrospinal fluid from 14 July 2019 to 15 December 2020,were reviewed from six major hospitals in Peninsular Malaysia.Inclusion criteria were invasive GBS,sterile sites and non-repeated GBS isolated from the same patients in the same admission.Viable isolates were re-identified for GBS and serotyped.Results:A total of 118 patients were eligible,with a majority of non-pregnant adults(76.3%).Over half of the patients(62.7%)had underlying medical conditions,with diabetes as the most common disease,followed by respiratory disease,renal disease,cardiovascular disease and skin and soft tissue disease.The most common manifestations were sepsis,followed by soft tissue abscess,diabetic foot ulcer,wet gangrene and cellulitis.The overall mortality was 7.6%.The most common serotype was serotype桋.Conclusions:Invasive GBS infection among non-pregnant adults showed a rising trend,particularly among diabetic individuals.The study underscores the importance of reducing risk factors and highlights the necessity of developing GBS vaccination as a preventive strategy for both infants and adults.

Analysis of anti-infection therapeutic schedule analysis for neonatal Streptococcus agalactiae meningitis and discussion on the indications for drug withdrawal

The clinical manifestations of neonatal GBS meningitis are as follows:non-specificity,long hospital stay,easy to cause neurological complications,and sequelae.Clinical pharmacist participated in the anti-infective treatment of a neonatal Streptococcus agalactiae meningitis whose cerebrospinal fluid was still abnormal when the drug was stopped.According to the PK/PD characteristics of antibacterial drugs,the permeability of the blood-brain barrier,and the adjustment of the antibiotic dose,the reasons for the decrease in the number of cerebrospinal fluid cells after vancomycin treatment were analyzed.Clinical pharmacists also analyzed the efficacy of linezolid in the treatment of neonatal bacterial meningitis,and discussed the indications for stopping medication when the cerebrospinal fluid is abnormal,so as to improve the safety and effectiveness of antibiotics in the treatment of neonatal bacterial meningitis.

Streptococcus agalactiae Anterior Cervical Space and Superior Mediastinum Abscess in a Liver Transplant Recipient

Introduction Streptococcus agalactiae is most commonly associated with pregnancy-related infections,neonatal sepsis,and infections in patients with immunocompromised states,such as diabetes mellitus and malignancies.1 Although abscesses caused by S.agalactiae are sometimes encountered in immunocompromised patients,S.agalactiae abscess in transplant recipients is extremely rare.S.agalactiae abscesses have never been reported in liver transplant recipients.In this article,we report a case of S.agalactiae abscess in the anterior cervical space extending to the superior mediastinum in a liver transplant recipient.

Vaginal Carriage of Group B Streptococcus in Pregnant Women in Rural Areas in Senegal

Vaginal carriage of Group B Streptococcus (GBS) is a maternal and child health issue. Our objective was to determine the prevalence of GBS carriage;identify the factors associated with this carriage and determine the antibiotic sensitivity of the isolated strains. We conducted a cross-sectional and prospective study in rural Senegal (in the health district of Sokone). Socio-demographic, clinical and gynaeco-obstetrical data were collected. Vaginal swabs were taken by the midwives on specific settings in order to test for GBS and other High Risk Vaginal Bacteria (HRVB). Antibiotic susceptibility testing was done according to the recommendations of the CA SFM/EUCAST 2020. In total, 100 pregnant women were targeted and 97 pregnant women were included. Their age ranged from 18 to 40 years with 64.9% (63/97) of participants belonging to the “20 - 30” age group. The overall prevalence of Group B Streptococcus carriage was 15.5% (15/97). However, the proportion of women with at least one high risk infectious bacteria was 29.89% (29/97). No statistically significant differences were found between GBS carriage and the potential factors studied. However, the study also looked for the presence of other high-risk bacteria and coinfections were indeed found between GBS and E. coli and Staphylococcus aureus. Antibiotic susceptibility testing shows that GBS strains were fully susceptible to penicillin G, erythromycin, clindamycin, chloramphenicol, rifampicin and vancomycin. Sensitivities to norfloxacin and gentamycin were 73.3% and 86.7% respectively. In contrast, high resistance to tetracycline (86.7%) was observed. GBS carriage remains a major public health issue because of its consequences for the mother and the newborn. Correct screening and proper monitoring of strain susceptibility remain one of the most effective means of patient management and care.

In Vitro Antibacterial Effect of Traditional Chinese Medicine on Main Pathogenic Bacteria of Recessive Mastitis in Dairy Cows

The inhibition zone diameter, minimal inhibitory concentration （MIC） and minimum bactericidal concentration （MBC） of 20 kinds of traditional Chi- nese medicine on Staphylococcus aureus and Streptococcus agalactiae isolated from recessive mastitis were studied using plate test and tube test. The results showed that S. aureus and S. agalactiae were sensitive to all these 20 kinds of traditional Chinese medicine, and were more sensitive to seven kinds of traditional Chinese medicine, including Taraxtwum mongolicum, Coptis chinensis, Forsythia suspense, Andrographis paniculata, Carthamus tinctorius, Scutellaria baicalensis and Den- dranthema indicum.

Observation of Traditional Chinese Medicine's Anti-bacterial Effect on the Main Pathogenic Bacteria of Dairy Cow Recessive Mastitis

[Objective]This paper aimed to study the anti-bacterial effect of traditional Chinese medicine on cow recessive mastitis＇ s main pathogenic bacteria and provide basis for its clinical application.[Method]Plating and test-tube methods were used to determine the anti-bacterial diameter,minimum inhibitory concentration（MIC）and minimum bactericidal concentration（MBC）of 20 kinds of traditional Chinese medicine on dairy cow recessive mastitis＇ s clinically isolated main pathogenic bacteria,Staphylococcus aureus and Streptococcus agalactiae.[Conclusion]The results indicated that 7 kinds of traditional Chinese medicine,Herba Taraxaci,Rhizoma Coptidis,Fructus Forsythiae,Herba Andrographis,Radix Scutellar iae,Flos Carthami,Flos Chrysanthemi Indici had strong anti-bacterial effect.

The relationship between sexually transmitted microorganisms and seminal quality in asymptomatic men

Objective:To detect DNA of different microorganisms,in semen samples from apparently healthy men and correlate their presence with seminal quality.Methods:Semensamples from 81 healthy volunteers were collected,and semen parameters were analyzed.DNA extraction was performed using the phenol-chloroform technique,and the micro-organisms were detected by the amplification of specific primers using polymerase chain reaction.Results:DNA from at least one of the microorganisms was detected in 78 samples.The most frequent microorganism found in semen were:Lactobacillus spp.(70%),Neisseria gonorrhoeae(N.gonorrhoeae)(36%),Streptococcus epidermidis(64%),Klebsiella pneumoniae(56%),Staphylococcus aureus(32%),Chlamydia trachomatis(C.trachomatis)(28%),Pseudomonas aeru-ginosa(27%).The seminal parameters of all semen samples were over the lower reference values fornormal semenanalysis.To compare with negative samples,seminal volume was higher for the Escherichia coli positive samples and lower for Pseudomonas aeruginosa positive samples.Semen samples positive for Staphylococcus aureus had worse sperm morphology.The frequency of progressive motility was higher in positive samples for N.gonorrhoeae and C.trachomatis.Positive semen samples for C.trachomatis had a higher concentration per milliliter.Conclusion:It is common to find microorganisms in semen of asymptomatic men,including those responsible for sexually transmitted infections.Antimicrobial treatment is recommended only in those individuals with a sexually transmitted infection(C.trachomatis and N.gonorrhoeae)and always promote condom use.

Isolation and Identification of the Pathogens of Bullfrog Streptoccus Disease

The tested strain from typical clinical cases,and the physio-chemical characteristics,16 S rRNA gene sequence and drug sensitivity challenge property were analyzed.This isolate was determined as Streptococcus agalactiae,16 S rRNA gene fragment of 1 280 bp in length.Blast analysis showed that this fragment shared a 100% homology with the conservative region of Streptococcus agalactiae isolate（AB023574）,Streptococcus dysqalactiae isolate（HM146084.1,AB537922,EU075033）,Streptococcus difficilis isolate（AB112407） accessed in Genbank.The isolate was sensitive to ciprofloxacin,neomycin,spectinomycin,furadantin and enoxacin.The results lay foundation for the effective control,rational medication and vaccine preparation for Streptococcus disease on bullfrogs.

Distribution and Prevalence of Serotypes of Group B Streptococcus Isolated from Pregnant Women in 30 Countries:A Systematic Review

Objective:This review aimed to compile scientific data on the distribution and prevalence of group BStreptococcus (GBS) serotypes isolated from pregnant women across 30 countries from 2010 to 2019.Methods:This was a systematic review that addresses the distribution and prevalence of GBS in pregnant women.The search included studies published between January 2010 and December 2019 in PubMed,Virtual Health Library (BVS),ScienceDirect,Scientific Electronic Library Online (SciELO),and LILACS databases.We also surveyed relevant articles published in English,Spanish,and Portuguese between February and April 2020.Original articles,communication,short report,theses,and dissertations were included.The prevalence of GBS colonization,method for capsular serotyping,antimicrobial resistance,distribution and prevalence of serotypes were extracted from each study.Results:In all,795 publications were identified.After applying the eligibility criteria,48 articles were included for the final systematic analysis;most articles were from Asia and were published during the years 2014 to 2017.For the identification of serotypes,most studies used the polymerase chain reaction technique.There were records of all 10 GBS serotypes,namely,Ia,Ib,and II–IX,among the countries analyzed.GBS susceptibility and resistance to antibiotics were addressed in 37.5% of the publications analysed.Conclusion:This review showed that GBS serotypes are distributed differently in the 30 analyzed countries,with serotypes Ia,Ib,and II to V being the most prevalent.Furthermore,our results highlighted the relationship of GBS with maternal colonization,implications for neonates,and antibiotic resistance.

Sequential One-Pot Three-Enzyme Synthesis of the Tetrasaccharide Repeating Unit of Group B Streptococcus Serotype Ⅷ Capsular Polysaccharide

The biochemical property and functional identification of three recombinant glycosyltransferases,includingβ-1,4-rhamnosyltransferase(Cps8R),β-1,4-galactosyltransferase(Cps8) and α-2,3-sialyltransferase(Cps8K)involved in the biosynthesis of the tetrasaccharide repeating unit of serotypeⅧcapsular polysaccharide(CPS)of Group B Streptococci(GBS),were systematically investigated.Subsequently,these recombinant enzymes were employed for one-pot three-enzyme efficient synthesis of the tetrasaccharide repeating unit of GBS serotypeⅧCPS using the chemically synthesized Glca-PP-(CH2)ir-OPh as the starting substrate in a satisfying yieldof 87%.