scholarly journals Omadacycline efficacy against Streptococcus agalactiae isolated in China: in vitro activity, resistance analysis, clonality of MIC distribution, and the correlation between resistance and virulence gene and biofilm formation

2020 ◽  
Author(s):  
Guiqiu Li ◽  
Ying Wei ◽  
Yan Guo ◽  
Jie Lian ◽  
Shaoyuan Wu ◽  
...  
Keyword(s):  
Streptococcus Agalactiae ◽  
Biofilm Formation ◽  
Reproductive Tract ◽  
Venous Blood ◽  
Virulence Gene ◽  
Inhibition Zone ◽  
Resistance Rate ◽  
Erythromycin Resistance ◽  
Urethral Discharge

Abstract Purpose: This study aimed to evaluate activity，resistance, clonality of MIC distribution, and the correlation between virulence＆resistance gene and biofilm formation of omadacycline (OMC) in clinical for Streptococcus agalactiae isolates from China.Methods: 162 isolates were collected retrospectively in China from 2018 to 2019. The S. agalactiae were mainly collected from the body's cervical secretions, wound secretions, ear swab, secretions, semen, venous blood, cerebrospinal fluid, pee, urethral discharge, pus, umbilical secretions, wound secretions, reproductive tract secretions, sputum, gastric juice, throat swab, eye secretions and amniotic fluid. The MIC of OMC against S. agalactiae were determined by broth microdilution. Filter paper was used to measure the inhibition zone diameters of OMC and other common antibiotics. D-test detected the incidence of erythromycin resistance to inductively clindamycin. Multilocus sequence typing (MLST)，resistance＆virulence gene of the isolates were investigated using qRT-PCR. Biofilms were detected by crystal violet staining.Results: The OMC MIC of clinical S. agalactiae isolates ranged from ≤0.25 to 0.5 mg/L. 19.7% of the S. agalactiae isolates with an OMC MIC of 0.25 mg/L were found to be sequence type (ST) 17. The S. agalactiae had highly resistant to Minocyclin, Erytromycin, Solithromycin and Clindamycin and the resistance rate of OMA was 13.6%. The positive rate of D-test was 90.74 %. The formation of biofilm was related to scpB gene, and indicated the resistance of OMA may be related to the virulence gene scpB. Conclusion: OMC exhibited better activity against clinical S. agalactiae isolates from China than DOX or MIN, and scpB was related with biofilm formation in OMC- resistance S. agalactiae.

scholarly journals Phytochemical Composition and In Vitro Antimicrobial Activity of Essential Oils from the Lamiaceae Family against Streptococcus agalactiae and Candida albicans Biofilms

Antibiotics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 592
Author(s):  
Ramona Iseppi ◽  
Roberta Tardugno ◽  
Virginia Brighenti ◽  
Stefania Benvenuti ◽  
Carla Sabia ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Candida Albicans ◽  
Essential Oils ◽  
Streptococcus Agalactiae ◽  
Reproductive Tract ◽  
Bacterial Species ◽  
Female Reproductive Tract ◽  
Retention Data ◽  
Natural Defense

The antimicrobial activity of different essential oils (EOs) from the Lamiaceae family was evaluated on Streptococcus agalactiae, Candida albicans, and lactobacilli. S. agalactiae is the main cause of severe neonatal infections, such as sepsis, meningitis, and pneumonia. C. albicans is a primary causative agent of vulvovaginal candidiasis, a multifactorial infectious disease of the lower female reproductive tract. Lactobacilli represent the dominant bacterial species of the vaginal flora and constitute the natural defense against pathogens. On the basis of the preliminary results, the attention was focused on the EOs from Lavandula x intermedia Emeric ex Loisel. and Mentha arvensis L. By using gas ghromatography (GS) retention data and mass spectra, it was possible to identify more than 90% of the total composition of the EO samples. The minimal inhibitory concentration (MIC) and anti-biofilm activity of the two EOs were determined against all isolated strains, using the EOs by themselves or in combination with each other and with drugs (erythromycin and fluconazole). The results showed a good antimicrobial and anti-biofilm activity of both EOs and a synergistic effect, leading to the best results against all the strains, resulted using the combinations EOs/EOs and antimicrobials/EOs.

scholarly journals Phage φAB6-Borne Depolymerase Combats Acinetobacter baumannii Biofilm Formation and Infection

Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 279
Author(s):  
Md. Shahed-Al-Mahmud ◽  
Rakesh Roy ◽  
Febri Gunawan Sugiokto ◽  
Md. Nazmul Islam ◽  
Ming-Der Lin ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Biofilm Formation ◽  
Bacterial Infections ◽  
Capsular Polysaccharide ◽  
Foley Catheter ◽  
Inhibition Zone ◽  
Control Group ◽  
Bacterial Cells ◽  
Bacterial Lawn

Biofilm formation is one of the main causes of increased antibiotic resistance in Acinetobacter baumannii infections. Bacteriophages and their derivatives, such as tail proteins with depolymerase activity, have shown considerable potential as antibacterial or antivirulence agents against bacterial infections. Here, we gained insights into the activity of a capsular polysaccharide (CPS) depolymerase, derived from the tailspike protein (TSP) of φAB6 phage, to degrade A. baumannii biofilm in vitro. Recombinant TSP showed enzymatic activity and was able to significantly inhibit biofilm formation and degrade formed biofilms; as low as 0.78 ng, the inhibition zone can still be formed on the bacterial lawn. Additionally, TSP inhibited the colonization of A. baumannii on the surface of Foley catheter sections, indicating that it can be used to prevent the adhesion of A. baumannii to medical device surfaces. Transmission and scanning electron microscopy demonstrated membrane leakage of bacterial cells treated with TSP, resulting in cell death. The therapeutic effect of TSP in zebrafish was also evaluated and the results showed that the survival rate was significantly improved (80%) compared with that of the untreated control group (10%). Altogether, we show that TSP derived from φAB6 is expected to become a new antibiotic against multi-drug resistant A. baumannii and a biocontrol agent that prevents the formation of biofilms on medical devices.

scholarly journals Phenotypic and Genotypic Characterization of Virulence Factors and Susceptibility to Antibiotics in Salmonella Infantis Strains Isolated from Chicken Meat: First Findings in Chile

Animals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1049
Author(s):  
Lisette Lapierre ◽  
Javiera Cornejo ◽  
Sebastián Zavala ◽  
Nicolás Galarce ◽  
Fernando Sánchez ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Biofilm Formation ◽  
Virulence Genes ◽  
Antibiotic Resistance Genes ◽  
Virulence Gene ◽  
Chicken Meat ◽  
Poultry Production ◽  
Production Chain ◽  
Salmonella Serotype

Salmonella Infantis is a zoonotic pathogen that causes gastroenteritis in humans and animals, with poultry being its main reservoir. In Chile, there are no data to characterize S. Infantis strains in poultry production. In this study, 87 S. Infantis strains were isolated from chicken meat for sale in supermarkets in Santiago, Chile, and characterized according to their virulence genes, biofilm formation abilities, antibiotic susceptibility, and resistance genes. Through polymerase chain reaction or PCR, the strains were analyzed to detect the presence of 11 virulence genes, 12 antibiotic resistance genes, and integrase genes. Moreover, disc diffusion susceptibility to 18 antimicrobials and the ability to form biofilm in vitro were evaluated. Results demonstrated six different virulence gene profiles. Ninety-four percent of the strains were multi-resistant to antibiotics with weak biofilm formation abilities, 63.2% of the strains were broad spectrum β- lactam resistant, and the bla CTX-M-65 gene was amplified in 13 strains. Only 3.4% of the strains were fluoroquinolone resistant, and the qnrB gene was amplified in two strains. Colistin resistance was exhibited in 28.7% of the strains, but mrc genes were not amplified in any strain under study. The isolated S. Infantis strains are pathogenic and antibiotic multi-resistant, and thus, this Salmonella serotype should be under surveillance in the poultry food production chain with the aim of protecting public health.

scholarly journals Phosphodiesterase Genes Regulate Amylovoran Production, Biofilm Formation, and Virulence inErwinia amylovora

2018 ◽  
Vol 85 (1) ◽  
Author(s):  
Roshni R. Kharadi ◽  
Luisa F. Castiblanco ◽  
Christopher M. Waters ◽  
George W. Sundin
Keyword(s):  
Biofilm Formation ◽  
Erwinia Amylovora ◽  
Virulence Gene ◽  
Virulence Determinants ◽  
Content Type ◽  
Precise Control ◽  
Intracellular Degradation ◽  
Successful Infection ◽  
And Function

ABSTRACTCyclic di-GMP (c-di-GMP) is a ubiquitous bacterial second messenger molecule that is an important virulence regulator in the plant pathogenErwinia amylovora. Intracellular levels of c-di-GMP are modulated by diguanylate cyclase (DGC) enzymes that synthesize c-di-GMP and by phosphodiesterase (PDE) enzymes that degrade c-di-GMP. The regulatory role of the PDE enzymes inE. amylovorahas not been determined. Using a combination of single, double, and triple deletion mutants, we determined the effects of each of the four putative PDE-encoding genes (pdeA,pdeB,pdeC, andedcA) inE. amylovoraon cellular processes related to virulence. Our results indicate thatpdeAandpdeCare the two phosphodiesterases most active in virulence regulation inE. amylovoraEa1189. The deletion ofpdeCresulted in a measurably significant increase in the intracellular pool of c-di-GMP, and the highest intracellular concentrations of c-di-GMP were observed in the Ea1189 ΔpdeACand Ea1189 ΔpdeABCmutants. The regulation of virulence traits due to the deletion of thepdegenes showed two patterns. A stronger regulatory effect was observed on amylovoran production and biofilm formation, where both Ea1189 ΔpdeAand Ea1189 ΔpdeCmutants exhibited significant increases in these two phenotypesin vitro. In contrast, the deletion of two or morepdegenes was required to affect motility and virulence phenotypes. Our results indicate a functional redundancy among thepdegenes inE. amylovorafor certain traits and indicate that the intracellular degradation of c-di-GMP is mainly regulated bypdeAandpdeC, but they also suggest a role forpdeBin regulating motility and virulence.IMPORTANCEPrecise control of the expression of virulence genes is essential for successful infection of apple hosts by the fire blight pathogen,Erwinia amylovora. The presence and buildup of a signaling molecule called cyclic di-GMP enables the expression and function of some virulence determinants inE. amylovora, such as amylovoran production and biofilm formation. However, other determinants, such as those for motility and the type III secretion system, are expressed and functional when cyclic di-GMP is absent. Here, we report studies of enzymes called phosphodiesterases, which function in the degradation of cyclic di-GMP. We show the importance of these enzymes in virulence gene regulation and the ability ofE. amylovorato cause plant disease.

scholarly journals In -vitro Biofilm Formation of Vaginal Isolates of Streptococcus agalactiae; Effect of pH and Culture Media

2021 ◽  
Vol 64 ◽  
Author(s):  
Guruge Niluka Dilrukshi ◽  
Jananie Kottahachchi ◽  
Thushari Dissanayake ◽  
Manjula Weerasekera ◽  
Mudara Peiris ◽  
...  
Keyword(s):  
Streptococcus Agalactiae ◽  
Biofilm Formation ◽  
Culture Media ◽  
Effect Of Ph

scholarly journals Antimicrobial Susceptibilities of Multidrug-Resistant Campylobacter jejuni and C. coli Strains: In Vitro Activities of 20 Antimicrobial Agents

2009 ◽  
Vol 54 (3) ◽  
pp. 1232-1236 ◽  
Author(s):  
Mirva Lehtopolku ◽  
Ulla-Maija Nakari ◽  
Pirkko Kotilainen ◽  
Pentti Huovinen ◽  
Anja Siitonen ◽  
...  
Keyword(s):  
Campylobacter Jejuni ◽  
Antimicrobial Agents ◽  
Agar Plate ◽  
Inhibition Zone ◽  
Multidrug Resistant ◽  
Dilution Method ◽  
Erythromycin Resistance ◽  
Disk Diffusion Test ◽  
Resistant Strains

ABSTRACT There is a paucity of information regarding antimicrobial agents that are suitable to treat severe infections caused by multidrug-resistant Campylobacter spp. Our aim was to identify agents that are potentially effective against multiresistant Campylobacter strains. The in vitro activities of 20 antimicrobial agents against 238 Campylobacter strains were analyzed by determining MICs by the agar plate dilution method or the Etest. These strains were selected from 1,808 Campylobacter isolates collected from Finnish patients between 2003 and 2005 and screened for macrolide susceptibility by using the disk diffusion test. The 238 strains consisted of 183 strains with erythromycin inhibition zone diameters of ≤23 mm and 55 strains with inhibition zone diameters of >23 mm. Of the 238 Campylobacter strains, 19 were resistant to erythromycin by MIC determinations (MIC ≥ 16 μg/ml). Given that the resistant strains were identified among the collection of 1,808 isolates, the frequency of erythromycin resistance was 1.1%. All erythromycin-resistant strains were multidrug resistant, with 18 (94.7%) of them being resistant to ciprofloxacin (MIC ≥ 4 μg/ml). The percentages of resistance to tetracycline and amoxicillin-clavulanic acid (co-amoxiclav) were 73.7% and 31.6%, respectively. All macrolide-resistant strains were susceptible to imipenem, meropenem, and tigecycline. Ten (52.6%) multiresistant strains were identified as being Campylobacter jejuni strains, and 9 (47.4%) were identified as being C. coli strains. These data demonstrate that the incidence of macrolide resistance was low but that the macrolide-resistant Campylobacter strains were uniformly multidrug resistant. In addition to the carbapenems, tigecycline was also highly effective against these multidrug-resistant Campylobacter strains in vitro. Its efficacy for the treatment of human campylobacteriosis should be evaluated in clinical trials.

scholarly journals Acidic pH Strongly EnhancesIn VitroBiofilm Formation by a Subset of Hypervirulent ST-17 Streptococcus agalactiae Strains

2014 ◽  
Vol 80 (7) ◽  
pp. 2176-2185 ◽  
Author(s):  
Nunzia D'Urzo ◽  
Manuele Martinelli ◽  
Alfredo Pezzicoli ◽  
Virginia De Cesare ◽  
Vittoria Pinto ◽  
...  
Keyword(s):  
Streptococcus Agalactiae ◽  
Biofilm Formation ◽  
Medium Composition ◽  
Proteinase K ◽  
Neonatal Meningitis ◽  
Neonatal Infections ◽  
Content Type ◽  
Acidic Conditions ◽  
Group B

ABSTRACTStreptococcus agalactiae, also known as group BStreptococcus(GBS), is a primary colonizer of the anogenital mucosa of up to 40% of healthy women and an important cause of invasive neonatal infections worldwide. Among the 10 known capsular serotypes, GBS type III accounts for 30 to 76% of the cases of neonatal meningitis. In recent years, the ability of GBS to form biofilm attracted attention for its possible role in fitness and virulence. Here, a newin vitrobiofilm formation protocol was developed to guarantee more stringent conditions, to better discriminate between strong-, low-, and non-biofilm-forming strains, and to facilitate interpretation of data. This protocol was used to screen the biofilm-forming abilities of 366 GBS clinical isolates from pregnant women and from neonatal infections of different serotypes in relation to medium composition and pH. The results identified a subset of isolates of serotypes III and V that formed strong biofilms under acidic conditions. Importantly, the best biofilm formers belonged to serotype III hypervirulent clone ST-17. Moreover, the abilities of proteinase K to strongly inhibit biofilm formation and to disaggregate mature biofilms suggested that proteins play an essential role in promoting GBS biofilm initiation and contribute to biofilm structural stability.

scholarly journals The Bvg Virulence Control System Regulates Biofilm Formation in Bordetella bronchiseptica

2004 ◽  
Vol 186 (17) ◽  
pp. 5692-5698 ◽  
Author(s):  
Yasuhiko Irie ◽  
Seema Mattoo ◽  
Ming H. Yuk
Keyword(s):  
Biofilm Formation ◽  
Virulence Gene ◽  
Bordetella Bronchiseptica ◽  
Signal Transduction System ◽  
Regulate Gene Expression ◽  
Two Component ◽  
Two Component Signal Transduction ◽  
Phase Encode ◽  
Regulate Gene

ABSTRACT Bordetella species utilize the BvgAS (Bordetella virulence gene) two-component signal transduction system to sense the environment and regulate gene expression among at least three phases: a virulent Bvg+ phase, a nonvirulent Bvg− phase, and an intermediate Bvgi phase. Genes expressed in the Bvg+ phase encode known virulence factors, including adhesins such as filamentous hemagglutinin (FHA) and fimbriae, as well as toxins such as the bifunctional adenylate cyclase/hemolysin (ACY). Previous studies showed that in the Bvgi phase, FHA and fimbriae continue to be expressed, but ACY expression is significantly downregulated. In this report, we determine that Bordetella bronchiseptica can form biofilms in vitro and that the generation of biofilm is maximal in the Bvgi phase. We show that FHA is required for maximal biofilm formation and that fimbriae may also contribute to this phenotype. However, expression of ACY inhibits biofilm formation, most likely via interactions with FHA. Therefore, the coordinated regulation of adhesins and ACY expression leads to maximal biofilm formation in the Bvgi phase in B. bronchiseptica.

scholarly journals Electrolytes, Metabolic And Acid-Base Parameters In Blood And Fluids of The Reproductive Tract During In Vivo Maturation of Bovine Oocytes

2021 ◽  
Author(s):  
Omer F. Gungor ◽  
Saleh Salman ◽  
Saurav Ranjitkar ◽  
Delong Zhang ◽  
Xiuchun (Cindy) Tian
Keyword(s):  
Oocyte Maturation ◽  
Follicular Fluid ◽  
Reproductive Tract ◽  
Venous Blood ◽  
Acid Base ◽  
Time Points ◽  
Base Parameters ◽  
Bovine Oocytes

Abstract Follicular fluid is the microenvironment that supports oocyte maturation and competence. Using Abbott iSTAT1™ and NanoDrop, we determined the dynamics of acid-base, electrolyte, metabolites, and total protein in venous blood, fluids of the dominant follicle (FF), oviduct (OF), and uterus (UF) during the window of oocyte maturation. Holstein heifers (n=36) were synchronized with PGF2α on Days -11 and 0, CIDR during Days -6 to 1, and GnRH given on Day 2 after 2nd PG. Samples were collected at 24h, 48h, 60h, 72h, and 78h after 2nd PG. Most electrolytes analyzed, Cl-, K+, and Ca2+ were significantly affected in blood and FF (P<0.05) by CIDR removal. Similarly, Cl- and Na+ also significantly changed in OF and UF across time. Glucose, lactate, and creatinine significantly changed across time points in FF compared to blood. Moreover, pO2, pCO2, TCO2, and pH significantly changed across time in FF. Most parameters were not significantly correlated between blood and FF across time points except for glucose, Cl- and creatinine. Furthermore, pO2 in FF was nearly 3X higher than blood, suggesting low O2 during in vitro maturation is inappropriate. In conclusion, components of the follicular fluid undergo major changes during the window of oocyte maturation.

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