scholarly journals Antimicrobial resistance, virulence genes and biofilm formation in Enterococcus species isolated from milk of sheep and goat with subclinical mastitis

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259584
Author(s):  
Mona A. El-Zamkan ◽  
Hams M. A. Mohamed
Keyword(s):  
Multidrug Resistance ◽  
Antimicrobial Resistance ◽  
Biofilm Formation ◽  
Virulence Genes ◽  
Subclinical Mastitis ◽  
Virulence Determinants ◽  
Antimicrobial Susceptibility Test ◽  
Rdna Sequencing ◽  
Dairy Animals ◽  
Mastitic Milk

This study is designed to discuss the antimicrobial resistance, virulence determinants and biofilm formation capacity of Enterococcus spp. isolated from milk of sheep and goat with subclinical mastitis in Qena, Egypt. The obtained isolates were identified by the VITEK2 system and 16S rDNA sequencing as E. faecalis, E. faecium, E. casseliflavus and E. hirae. Overall, E. faecalis and E. faecium were the dominant species recovered from mastitic milk samples. The antimicrobial susceptibility test evidenced multidrug resistance of the isolates against the following antimicrobials: oxacillin (89.2.%), followed by vancomycin (75.7%) and linezolid (70.3%). Also, most of these isolates (73%) could form biofilms. For example, 18.9% of Enterococcus strains formed strong biofilm, whereas 32.4% of isolates formed moderate biofilm and 21.6% of isolates formed weak biofilm. The most prevalent resistance genes found in our isolates were blaZ (54%), vanA (40%), ermB (51.4%), tetM (13.5%) and optrA (10.8%). Moreover, asa1 (37.8%), cylA (42.3%), gelE (78.4%), esp (32.4%), EF3314(48.6%) and ace (75.5%) were the most common virulence genes. A significant correlation was found between biofilm formation, multidrug resistance and virulence genes of the isolates. This study highlights several aspects of virulence and harmfulness of Enterococcus strains isolated from subclinical mastitic milk, which necessitates continuous inspection and monitoring of dairy animals.

Characterization of biofilms and antimicrobial resistance of coagulase-negative Staphylococcus species involved with subclinical mastitis

2021 ◽  
pp. 1-6
Author(s):  
Márcia Silva Francisco ◽  
Ciro César Rossi ◽  
Maria Aparecida Vasconcelos Paiva Brito ◽  
Marinella Silva Laport ◽  
Elaine Menezes Barros ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Biofilm Formation ◽  
Subclinical Mastitis ◽  
Penicillin G ◽  
Coagulase Negative Staphylococcus ◽  
Central Feature ◽  
High Genetic Diversity ◽  
Dairy Animals

Abstract Biofilm formation is a central feature to guarantee staphylococcal persistence in hosts and is associated with several diseases that are difficult to treat. In this research paper, biofilm formation and antimicrobial susceptibility were investigated in staphylococcal strains belonging to several species. These strains were isolated from the milk of cows with subclinical mastitis and most of them were coagulase-negative, with the prevalence of Staphylococcus chromogenes. High genetic diversity was observed among the strains by pulsed field gel electrophoresis. Antimicrobial resistance was assessed by disk diffusion and more than 50% of the strains were resistant to ampicillin and penicillin G, with multi-resistance profiles (13.6%) also being observed. Most strains (65.9%) formed biofilms when cultivated in BHI supplemented with 1% glucose. Most strains (72.7%) carried the intercellular adhesion gene (icaA), while less than half (36.3%) carried the biofilm-associated protein gene (bap). Concentrations of up to 10xMIC of erythromycin and tetracycline were not sufficient to suppress cell viability in preformed biofilms. Our results revealed that a genetically diverse group of biofilm-forming Staphylococcus species can be involved in subclinical mastitis. Since high antimicrobial concentrations cannot eradicate biofilm cells in vitro, their use in dairy animals may be ineffective in controlling infections, while supporting selection of resistant microorganisms. These data reinforce the need for alternative therapies aiming at disrupting biofilms for effective disease control.

scholarly journals NDM-1-Positive K. pneumoniae at a Teaching Hospital in Southwestern China: Clinical Characteristics, Antimicrobial Resistance, Molecular Characterization, Biofilm Assay, and Virulence

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Kai Yang ◽  
Shumin Liu ◽  
Huanqin Li ◽  
Na Du ◽  
Jing Yao ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
Antimicrobial Resistance ◽  
Biofilm Formation ◽  
Neonatal Intensive Care ◽  
Clinical Characteristics ◽  
Statistical Difference ◽  
Virulence Genes ◽  
Control Group ◽  
Carrier Rate ◽  
Detection Rates

Background. The emergence of the NDM-1-positive Klebsiella pneumoniae (K. pneumoniae) strains has led to limited therapeutic options for clinical treatment. Understanding the clinical characteristics, antimicrobial resistance, biofilm assay, and the virulence genes of these isolated strains is of great significance. Methods. The polymerase chain reaction (PCR) was used to screen isolated NDM-1-positive K. pneumoniae. The clinical information of the patients was collected from medical records. The NDM-1-positive K. pneumoniae isolates were subjected to antimicrobial susceptibility testing and multilocus sequence typing. Sixty strains of NDM-1-negative K. pneumoniae isolated during the same period were collected as the control group for the virulence analysis. The virulence phenotype of the strains was preliminarily evaluated by the string test and crystal violet semiquantitative biofilm formation experiment. PCR combined with gene sequencing was used to detect common high toxicity capsule genes (K1, K2, K5, K20, K54, and K57) and common virulence-related genes (entB, ybtS, ureA, ycf, WabG, FimH, uge, iutA, KfuB, aerobactin, rmpA, magA, Alls, IrnN, and VatD). Results. In the 30 nonduplicated NDM-1-positive K. pneumoniae isolates, 43.33% (13/30) of the patients had a history of a stay in the neonatal intensive care unit (NICU). All of the isolates exhibited multidrug resistance. Nine STs were identified, 77% (10/13) strains from the NICU were ST11. The NDM-1-positive K. pneumoniae string tests were all negative, and 35% (21/60) NDM-1-negative K. pneumoniae were positive. The ratios of NDM-1-positive K. pneumoniae isolates biofilm formation ability according to strong, medium, and weak classification were 67%, 23%, and 10%, respectively. NDM-1-negative K. pneumoniae isolates were 60%, 25%, and 15%, respectively. There was no statistical difference between the two groups (t = 0.61, P=0.2723). The virulence-associated genes with more than 80% of detection rates among the 30 NDM-1-positive K. pneumoniae isolates included entB (100%, 30/30), ybtS (93.33%, 28/30), ureA (90%, 27/30), ycf (83.33%, 25/30), and wabG (90%, 27/30). KfuB and iutA were detected at prevalence of 3.33% and 13.33%. vatD, allS, iroN, aerobactin, and rmpA were not detected. In the NDM-1-negative K. pneumoniae, all other 14 virulence genes except VatD were detected. After statistical analysis, FimH, WabG, ycf, iutA, kfuB, aerobactin, rmpA, and Alls virulence genes, P<0.005, there was a statistical difference. Conclusion. NDM-1-positive K. pneumoniae exhibited multidrug resistance, MLST typing is mainly ST11, there is small clonal dissemination in the NICU in the hospital, and the NDM-1-positive K. pneumoniae virulence genes carrier rate is lower than the NDM-1-negative K. pneumoniae virulence genes carrier rate.

scholarly journals atpD gene sequencing, multidrug resistance traits, virulence-determinants, and antimicrobial resistance genes of emerging XDR and MDR-Proteus mirabilis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abdelazeem M. Algammal ◽  
Hany R. Hashem ◽  
Khyreyah J. Alfifi ◽  
Helal F. Hetta ◽  
Norhan S. Sheraba ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Proteus Mirabilis ◽  
Biofilm Formation ◽  
Gene Sequencing ◽  
Opportunistic Pathogen ◽  
Severe Illness ◽  
Virulence Determinants ◽  
Antimicrobial Resistance Genes ◽  
Port Said

AbstractProteus mirabilis is a common opportunistic pathogen causing severe illness in humans and animals. To determine the prevalence, antibiogram, biofilm-formation, screening of virulence, and antimicrobial resistance genes in P. mirabilis isolates from ducks; 240 samples were obtained from apparently healthy and diseased ducks from private farms in Port-Said Province, Egypt. The collected samples were examined bacteriologically, and then the recovered isolates were tested for atpD gene sequencing, antimicrobial susceptibility, biofilm-formation, PCR detection of virulence, and antimicrobial resistance genes. The prevalence of P. mirabilis in the examined samples was 14.6% (35/240). The identification of the recovered isolates was confirmed by the atpD gene sequencing, where the tested isolates shared a common ancestor. Besides, 94.3% of P. mirabilis isolates were biofilm producers. The recovered isolates were resistant to penicillins, sulfonamides, β-Lactam-β-lactamase-inhibitor-combinations, tetracyclines, cephalosporins, macrolides, and quinolones. Using PCR, the retrieved strains harbored atpD, ureC, rsbA, and zapA virulence genes with a prevalence of 100%, 100%, 94.3%, and 91.4%, respectively. Moreover, 31.4% (11/35) of the recovered strains were XDR to 8 antimicrobial classes that harbored blaTEM, blaOXA-1, blaCTX-M, tetA, and sul1 genes. Besides, 22.8% (8/35) of the tested strains were MDR to 3 antimicrobial classes and possessed blaTEM, tetA, and sul1genes. Furthermore, 17.1% (6/35) of the tested strains were MDR to 7 antimicrobial classes and harbored blaTEM, blaOXA-1, blaCTX-M, tetA, and sul1 genes. Alarmingly, three strains were carbapenem-resistant that exhibited PDR to all the tested 10 antimicrobial classes and shared blaTEM, blaOXA-1, blaCTX-M, tetA, and sul1 genes. Of them, two strains harbored the blaNDM-1 gene, and one strain carried the blaKPC gene. In brief, to the best of our knowledge, this is the first study demonstrating the emergence of XDR and MDR-P.mirabilis in ducks. Norfloxacin exhibited promising antibacterial activity against the recovered XDR and MDR-P. mirabilis. The emergence of PDR, XDR, and MDR-strains constitutes a threat alarm that indicates the complicated treatment of the infections caused by these superbugs.

scholarly journals Antimicrobial Resistance and Virulence Determinants in European Salmonella Genomic Island 1-Positive Salmonella enterica Isolates from Different Origins

2011 ◽  
Vol 77 (16) ◽  
pp. 5655-5664 ◽  
Author(s):  
Janine Beutlich ◽  
Silke Jahn ◽  
Burkhard Malorny ◽  
Elisabeth Hauser ◽  
Stephan Hühn ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
Antimicrobial Resistance ◽  
Salmonella Enterica ◽  
Genomic Island ◽  
Variable Number Tandem Repeat ◽  
Tetracycline Resistance ◽  
Variable Number ◽  
Virulence Determinants ◽  
Content Type ◽  
Strain Collection

ABSTRACTSalmonellagenomic island 1 (SGI1) contains a multidrug resistance region conferring the ampicillin-chloramphenicol-streptomycin-sulfamethoxazole-tetracycline resistance phenotype encoded byblaPSE-1,floR,aadA2,sul1, andtet(G). Its increasing spread via interbacterial transfer and the emergence of new variants are important public health concerns. We investigated the molecular properties of SGI1-carryingSalmonella entericaserovars selected from a European strain collection. A total of 38 strains belonging toS. entericaserovar Agona,S. entericaserovar Albany,S. entericaserovar Derby,S. entericaserovar Kentucky,S. entericaserovar Newport,S. entericaserovar Paratyphi B dT+, andS. entericaserovar Typhimurium, isolated between 2002 and 2006 in eight European countries from humans, animals, and food, were subjected to antimicrobial susceptibility testing, molecular typing methods (XbaI pulsed-field gel electrophoresis [PFGE], plasmid analysis, and multilocus variable-number tandem-repeat analysis [MLVA]), as well as detection of resistance and virulence determinants (PCR/sequencing and DNA microarray analysis). Typing experiments revealed wide heterogeneity inside the strain collection and even within serovars. PFGE analysis distinguished a total of 26 different patterns. In contrast, the characterization of the phenotypic and genotypic antimicrobial resistance revealed serovar-specific features. Apart from the classical SGI1 organization found in 61% of the strains, seven different variants were identified with antimicrobial resistance properties associated with SGI1-A (S. Derby), SGI1-C (S. Derby), SGI1-F (S. Albany), SGI1-L (S. Newport), SGI1-K (S. Kentucky), SGI1-M (S.Typhimurium), and, eventually, a novel variant similar to SGI1-C with additional gentamicin resistance encoded byaadB. Only minor serovar-specific differences among virulence patterns were detected. In conclusion, the SGI1 carriers exhibited pathogenetic backgrounds comparable to the ones published for susceptible isolates. However, because of their multidrug resistance, they may be more relevant in clinical settings.

scholarly journals Temporal Trends in Antimicrobial Resistance and Virulence-Associated Traits within the Escherichia coli Sequence Type 131 Clonal Group and ItsH30 andH30-Rx Subclones, 1968 to 2012

2014 ◽  
Vol 58 (11) ◽  
pp. 6886-6895 ◽  
Author(s):  
Bente Olesen ◽  
Jakob Frimodt-Møller ◽  
Rikke Fleron Leihof ◽  
Carsten Struve ◽  
Brian Johnston ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Multidrug Resistance ◽  
Antimicrobial Resistance ◽  
Virulence Genes ◽  
Temporal Trends ◽  
Sequence Type ◽  
Esbl Production ◽  
Content Type ◽  
E Coli ◽  
Biofilm Production

ABSTRACTTo identify possible explanations for the recent global emergence ofEscherichia colisequence type (ST) 131 (ST131), we analyzed temporal trends within ST131 O25 for antimicrobial resistance, virulence genes, biofilm formation, and theH30 andH30-Rx subclones. For this, we surveyed the WHOE. coliandKlebsiellaCentre'sE. colicollection (1957 to 2011) for ST131 isolates, characterized them extensively, and assessed them for temporal trends. Overall, antimicrobial resistance increased temporally in prevalence and extent, due mainly to the recent appearance of theH30 (1997) andH30-Rx (2005) ST131 subclones. In contrast, neither the total virulence gene content nor the prevalence of biofilm production increased temporally, although non-H30 isolates increasingly qualified as extraintestinal pathogenicE. coli(ExPEC). Whereas virotype D occurred from 1968 forward, virotypes A and C occurred only after 2000 and 2002, respectively, in association with theH30andH30-Rx subclones, which were characterized by multidrug resistance (including extended-spectrum-beta-lactamase [ESBL] production:H30-Rx) and absence of biofilm production. Capsular antigen K100 occurred exclusively amongH30-Rx isolates (55% prevalence). Pulsotypes corresponded broadly with subclones and virotypes. Thus, ST131 should be regarded not as a unitary entity but as a group of distinctive subclones, with its increasing antimicrobial resistance having a strong clonal basis, i.e., the emergence of theH30 andH30-Rx ST131 subclones, rather than representing acquisition of resistance by diverse ST131 strains. Distinctive characteristics of theH30-Rx subclone—including specific virulence genes (iutA,afaanddra,kpsII), the K100 capsule, multidrug resistance, and ESBL production—possibly contributed to epidemiologic success, and some (e.g., K100) might serve as vaccine targets.

scholarly journals Enterococci populations of a metropolitan river after an extreme flood event: prevalence, persistence and virulence determinants

2017 ◽  
Vol 15 (5) ◽  
pp. 684-694
Author(s):  
Nicole M. Masters ◽  
Aaron Wiegand ◽  
Jasmin M. Thompson ◽  
Tara L. Vollmerhausen ◽  
Eva Hatje ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Virulence Genes ◽  
Species Level ◽  
Flood Event ◽  
Recreational Water ◽  
Virulence Determinants ◽  
Extreme Flood ◽  
High Prevalence ◽  
Biochemical Fingerprinting ◽  
Multiple Antibiotics

We investigated the prevalence, persistence and virulence determinants of enterococci populations in water samples collected over three rounds following an extreme flood event in a metropolitan river. Enterococci (n = 482) were typed using the high resolution biochemical fingerprinting method (PhP typing) and grouped into common (C) or single (S) biochemical phenotypes (BPTs). In all, 23 C-BPTs (72.6% of isolates) were found across the sites. A representative isolate of each C-BPT was identified to the species level and tested for the presence of seven virulence genes (VGs), biofilm formation and resistance to 14 antibiotics. The enterococci concentrations in samples collected during the first two rounds were above national recreational water guidelines. By round three, enterococci concentrations decreased significantly (P &lt; 0.05). However, 11 C-BPTs (55.5% of isolates) persisted across all sampling rounds. E. casseliflavus and E. mundtii were the most common enterococci populations comprising of &gt;57% of all isolates. Ten of the 11 most dominant C-BPTs were resistant to multiple antibiotics and harboured one or more VGs. The high prevalence of antibiotic resistance and VGs among enterococci isolates in this catchment not only provides them with niche advantages but also poses a risk to public health.

scholarly journals Antimicrobial Resistance in Pseudomonas aeruginosa Biofilms

2021 ◽  
Author(s):  
Dhara Patel ◽  
Palash Sen ◽  
Yin Hlaing ◽  
Michael Boadu ◽  
Bassam Saadeh ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Multidrug Resistance ◽  
Antimicrobial Resistance ◽  
Growth Inhibition ◽  
Biofilm Formation ◽  
Broth Microdilution ◽  
Planktonic Cells ◽  
Biofilm Growth ◽  
Minimal Inhibitory Concentrations ◽  
Dose Dependent

Pseudomonas aeruginosa (PA) is part of a group of common nosocomial pathogens that exhibit multidrug resistance, thus proving to be a significant threat to healthcare. This study analyzes the ability of four commonly used antibiotics to observe eradication of the PA biofilm growth. Ceftazidime (CAZ), Tobramycin (TOB), Ofloxacin (OFLX), Meropenem (MEM), were tested against overnight cultures of PA strain PA01. The minimal inhibitory concentrations (MIC) of planktonic cells for all the four antibiotics were determined using broth microdilution while the minimal bactericidal concentrations (MBCs) were determined by colony count after antibiotic treatment and regrowth. Biofilm growth inhibition was performed by treating cells with antibiotic at the time of inoculation while eradication was determined by adding antibiotics 24 hours after inoculation, allowing mature biofilm formation, followed by the measurement of absorbance. PA planktonic cells exhibited the highest susceptibility to MEM compared to overnight grown PA biofilm which demonstrated resistance to CAZ, complete sensitivity to ofloxacin, and minimal sensitivity to TOB and MEM. PA biofilm displayed dose-dependent sensitivity to TOB, MEM and OFLX, and a significant level of resistance to CAZ during the inhibition phase. However, in the eradication phase, PA showed significant resistance to TOB followed by CAZ while PA biofilm showed sensitivity at higher concentrations of MEM. Our study exhibits that PA strain PA01 is resistant to ceftazidime in both planktonic and biofilm phases. While ofloxacin proved to be the most effective even at lower concentrations when compared with other antibiotics, tobramycin was most effective at higher concentrations for eradicating and inhibiting PA biofilms.

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