ADSRRS-fingerprinting and PCR MP techniques for studies of intraspecies genetic relatedness in Staphylococcus aureus

The main aim of this study was the characterization of antibiotic resistance mechanisms in 82 Staphylococcus aureus strains isolated from humans and animals. Antibiotic susceptibility testing was performed on all S. aureus isolates accordingly, and antibiotic-resistant genes were investigated by genotypic methods. The genetic diversity of S. aureus was studied through spa, multilocus sequence typing (MLST), and agr typing methods. The majority of S. aureus from human sources were resistant to cefoxitin (and harbor the mecA gene) and fluoroquinolones, whereas only four strains of S. aureus from animal sources revealed resistance to ciprofloxacin. In the set of S. aureus isolated from humans, the most frequent spa, MLST, and agr group were t032, ST22, and I, respectively. In strains from animal origin the most common spa, MLST, and agr group found were t2383, ST398, and III/not typable, respectively. S. aureus from humans and animals were identified either in clonal complexes CC5, CC30, and CC398, suggesting that they have the same putative founder in their evolution. Considering the three CCs encompassing strains from human and animal reservoirs with different spa-types, we can hypothesize that this might reflect an adaptation to different phylogenetic lineages in those reservoirs (host species) probably associated to genetic diversification of pre-existing strains.

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Genetic characterization of coagulase-positive staphylococci isolated from healthy pigeons

Polish Journal of Veterinary Sciences ◽

10.1515/pjvs-2015-0081 ◽

2015 ◽

Vol 18 (3) ◽

pp. 627-634 ◽

Cited By ~ 5

Author(s):

M. Kizerwetter-Świda ◽

D. Chrobak-Chmiel ◽

M. Rzewuska ◽

A. Antosiewicz ◽

B. Dolka ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Genetic Relatedness ◽

Genetic Characterization ◽

Restriction Patterns ◽

Feral Pigeons ◽

Group A ◽

Biochemical Identification ◽

Group B ◽

Coagulase Positive Staphylococci

AbstractCoagulase-positive staphylococci (CoPS) are opportunistic veterinary pathogens, of whichStaphylococcus aureus,S. delphiniandS. intermediuscan be isolated from pigeons. The biochemical identification ofS. delphiniandS. intermediusisolates may be incorrect, because of their phenotypic similarity. The purpose of the present study was to isolate and identify CoPS from domestic and feral pigeons and to determine their genetic relatedness by PFGE. A total number of 31 isolates of CoPS were obtained, 15 were identified asS. delphinigroup B, six asS. aureus,four asS. delphinigroup A, three asS. intermediusand three asS. schleiferisubsp.coagulans. The results indicate that S.delphinigroup B is the predominant CoPS species among pigeons studied. PFGE restriction patterns ofS. delphinigroup A andS. delphinigroup B form separate clusters, demonstrating their genetic heterogeneity. Indistinguishable or very similar PFGE patterns observed amongS. delphinigroup B isolates from domestic and feral pigeons confirm the possibility of CoPS transmission between these birds.

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Prevalence and genetic relatedness of community-acquired methicillin-resistant Staphylococcus aureus in Israel

European Journal of Clinical Microbiology & Infectious Diseases ◽

10.1007/s10096-006-0210-3 ◽

2006 ◽

Vol 25 (11) ◽

pp. 719-722 ◽

Cited By ~ 18

Author(s):

G. Regev-Yochay ◽

Y. Carmeli ◽

M. Raz ◽

E. Pinco ◽

J. Etienne ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Methicillin Resistant Staphylococcus Aureus ◽

Genetic Relatedness ◽

Methicillin Resistant

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Massive genome decay and expansion of insertion sequences drive the evolution of a novel host-restricted bacterial pathogen

10.1101/2020.10.13.331058 ◽

2020 ◽

Author(s):

Gonzalo Yebra ◽

Andreas F Haag ◽

Maan M Neamah ◽

Bryan A Wee ◽

Emily J Richardson ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Genetic Relatedness ◽

Bacterial Species ◽

Small Ruminants ◽

Bacterial Pathogen ◽

Insertion Sequences ◽

Evolutionary Trajectory ◽

Intergenic Regions ◽

Genome Decay ◽

Novel Concept

AbstractBackgroundThe emergence of new bacterial pathogens represents a major threat to public and veterinary health. Staphylococcus aureus is a multi-host bacterial species comprising pathogenic clones with distinct tropisms for human and livestock species. A S. aureus microaerophilic subspecies, Staphylococcus aureus subsp. anaerobius, is responsible for outbreaks of a specific lymphadenitis pathology (Morel’s disease) exclusively found in small ruminants. However, the evolutionary history of S. aureus subsp. anaerobius and its genetic relatedness to S. aureus are unknown.ResultsEvolutionary genomic analyses of clinical S. aureus subsp. anaerobius isolates sampled across 3 decades revealed this clone emerged from a S. aureus progenitor about 1000 years ago (95%CI: 716-1184), before differentiating into two distinct lineages representing African (emerged in 1930 [1907-1951)) and European (1777 [1716-1832]) isolates. S. aureus subsp. anaerobius has undergone limited clonal expansion, with a restricted population size, and an evolutionary rate 10-fold slower than S. aureus. The transition to a highly niche-specific pathogen of small ruminant lymph nodes involved acquisition of a pathogenicity island encoding an effector with ruminant host-specificity, large genomic rearrangements, and the accumulation of at least 205 pseudogenes resulting in a highly fastidious metabolism underpinning its restricted ecological niche. Importantly, acquisition and expansion of ~87 insertion sequences located in conserved intergenic regions provided distinct mechanisms for the control of expression of flanking genes, representing a novel concept of transcriptional regulon.ConclusionsOur findings provide a remarkable example of the evolutionary trajectory of a host-restricted bacterial pathogen that resulted from extensive remodelling of the S. aureus genome.

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Clonality, virulence genes, and antibiotic resistance of Staphylococcus aureus isolated from blood in Shandong, China

BMC Microbiology ◽

10.1186/s12866-021-02344-6 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Xuezhi Wang ◽

Dongzi Lin ◽

Zengqi Huang ◽

Jinmei Zhang ◽

Wenyan Xie ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Antibiotic Resistance ◽

Infection Control ◽

Virulence Genes ◽

Genetic Relatedness ◽

Protein A ◽

Epidemiological Data ◽

Control Measures ◽

Staphylococcal Protein A ◽

Infection Control Measures

Abstract Background Bloodstream infection (BSI) caused by Staphylococcus aureus (S. aureus) can be life-threatening and pose a great challenge to infection control and clinical treatment. However, little information exists regarding the characterization of S. aureus in BSI patients in Shandong, China. To identify the clonality, virulence genes, and antibiotic resistance of S. aureus in blood, a total of 101 nonrepetitive blood isolates were collected. The antibiotic resistance phenotypes were determined, and virulence genes were analyzed with polymerase chain reaction (PCR). Finally, the genetic relatedness was investigated with Staphylococcus chromosomal cassette mec (SCCmec) typing for methicillin-resistant S. aureus (MRSA) isolates, Staphylococcal protein A (spa), and multilocus sequence typing (MLST) for all of 101 isolates. Results Of the 101 S. aureus isolates, 24 MRSA isolates and 77 methicillin-susceptible S. aureus (MSSA) isolates were identified. Overall, MRSA isolates had higher resistance rates than MSSA isolates when exposed to any of the 15 antibiotics tested in this study except for trimethoprim/sulfamethoxazole. Among the 17 virulence genes tested in this study, hla, hld, and hlg could be detected in all isolates. MRSA isolates were more likely to carry seb and hlb genes, while MSSA isolates were more likely to carry seg and sei genes. Thirty-five sequence types (STs) and 49 spa types were identified, of which ST59-t437 and ST398-t571 were the most abundant. These two genotypes were also the most abundant ST-spa types in MRSA and MSSA isolates, but their abundances shifted over time, with ST398-t571 being the predominant genotype from 2016 to 2017, and ST59-t437 from 2018 to 2020. Besides, all the ST59-t437 isolates harbored hlgb gene, whereas most (88.9%) ST398-t571 did not. In addition, twenty-four MRSA isolates were subject to SCCmec typing. SCCmec IVa was the most prevalent SCCmec type, and all the ST59-t437 MRSA isolates were SCCmec IVa. We also observed 15 new STs, and some of them were MRSA. Conclusion These findings provide additional observations and epidemiological data for blood S. aureus isolates, which can improve future infection-control measures and aid in potential clinical treatments in hospitals and other clinical settings.

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Prevalence of fosfomycin resistance and gene mutations in clinical isolates of methicillin-resistant Staphylococcus aureus

10.21203/rs.2.23289/v1 ◽

2020 ◽

Author(s):

Yi-Chien Lee ◽

Pao-Yu Chen ◽

Jann-Tay Wang ◽

Shan-Chwen Chang

Keyword(s):

Staphylococcus Aureus ◽

Antimicrobial Agents ◽

Genetic Relatedness ◽

Protein A ◽

Gene Mutations ◽

Resistance Rate ◽

Staphylococcal Protein A ◽

Methicillin Resistant ◽

Fosfomycin Resistance

Abstract Background: Fosfomycin exhibits excellent in vitro activity against multidrug-resistant pathogens, including methicillin-resistant Staphylococcus aureus (MRSA). Increasing fosfomycin resistance among clinical MRSA isolates was reported previously, but little is known about the genetic mechanisms of fosfomycin resistance.Methods: All MRSA isolates, collected in 2002 and 2012 by the Taiwan Surveillance of Antimicrobial Resistance (TSAR) program, were used in this study. Susceptibility to various antimicrobial agents, including fosfomycin, was determined by broth microdilution. Genetic determinants of fosfomycin resistance, including fosB carriage and murA, glpT and uhpT mutations, were investigated using PCR and sequencing of amplicons. Staphylococcal protein A (spa) typing was also performed to determine the genetic relatedness of MRSA isolates.Results: A total of 969 MRSA strains, 495 in the year 2002 and 474 in the year 2012, were analyzed. The overall in vitro susceptibility was 8.2% to erythromycin, 18.0% to clindamycin, 29.0% to tetracycline, 44.6% to ciprofloxacin, 57.5% to trimethoprim/sulfamethoxazole, 86.9% to rifampicin, 92.9% to fosfomycin and 100% to linezolid and vancomycin. A significant increase in the fosfomycin resistance rate was observed from 3.4% in 2002 to 11.0% in 2012. Of 68 fosfomycin-resistant MRSA isolates, 12 harbored the fosB gene, and expression of murA, uhpT, and glpT mutations was noted in 11, 59, and 66 isolates, respectively. Combination of mutations of uhpT and glpT genes (58 isolates) was the most prevalent resistant mechanism. The vast majority of the fosfomycin-resistant MRSA isolates belonged to spa type t002.Conclusions: An increased fosfomycin resistance rate of MRSA isolates was observed in our present study, mostly due to mutations in the glpT and uhpT genes. Clonal spread probably contributed to the increased fosfomycin resistance.

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The Genetic Relatedness and Antimicrobial Resistance Patterns of Mastitis-Causing Staphylococcus aureus Strains Isolated from New Zealand Dairy Cattle

Veterinary Sciences ◽

10.3390/vetsci8110287 ◽

2021 ◽

Vol 8 (11) ◽

pp. 287

Author(s):

Sabrina S. Greening ◽

Ji Zhang ◽

Anne C. Midwinter ◽

David A. Wilkinson ◽

Scott McDougall ◽

...

Keyword(s):

Staphylococcus Aureus ◽

New Zealand ◽

Antimicrobial Resistance ◽

Genetic Relatedness ◽

Bovine Mastitis ◽

Subclinical Mastitis ◽

Antimicrobial Usage ◽

Dry Cow Therapy ◽

Usage Patterns ◽

Resistance Patterns

Staphylococcus aureus is one of the leading causes of bovine mastitis worldwide and is a common indication for use of antimicrobials on dairy farms. This study aims to investigate the association between on-farm antimicrobial usage and the antimicrobial resistance (AMR) profiles of mastitis-causing S. aureus. Whole-genome sequencing was performed on 57 S. aureus isolates derived from cows with either clinical or subclinical mastitis from 17 dairy herds in New Zealand. The genetic relatedness between isolates was examined using the core single nucleotide polymorphism alignment whilst AMR and virulence genes were identified in-silico. The association between gene presence-absence and sequence type (ST), antimicrobial susceptibility and dry cow therapy treatment was investigated using Scoary. Altogether, eight STs were identified with 61.4% (35/57) belonging to ST-1. Furthermore, 14 AMR-associated genes and 76 virulence-associated genes were identified, with little genetic diversity between isolates belonging to the same ST. Several genes including merR1 which is thought to play a role in ciprofloxacin-resistance were found to be significantly overrepresented in isolates sampled from herds using ampicillin/cloxacillin dry cow therapy. Overall, the presence of resistance genes remains low and current antimicrobial usage patterns do not appear to be driving AMR in S. aureus associated with bovine mastitis.

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