scholarly journals Antimicrobial resistance and molecular characterization of Streptococcus agalactiae from pregnant women in southern China

2019 ◽  
Vol 13 (09) ◽  
pp. 802-809
Author(s):  
Huiwu Guo ◽  
Maozhang Fu ◽  
Qing Peng ◽  
Zhuoran Chen ◽  
Jun Liu ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Pregnant Women ◽  
Streptococcus Agalactiae ◽  
Southern China ◽  
Variable Number Tandem Repeat ◽  
Virulence Gene ◽  
Variable Number ◽  
Considerable Proportion ◽  
Bacterial Strains ◽  
Clonal Relationship

Introduction: This study aimed to characterize antimicrobial resistance (AMR), molecular determinants of AMR and virulence, as well as clonal relationship of Streptococcus agalactiae isolates from women at 35-37 weeks of gestation in the Chaoshan metropolitan area of southern China. Methodology: Bacterial strains isolated from vaginal swabs were identified and antimicrobial susceptibility tests were performed by using a Vitek 2 Compact system (BioMérieux, France). Resistance and virulence genes were detected by polymerase chain reaction (PCR) and the clonal relationship was analysed by multiple locus variable number tandem repeat analysis (MLVA). Statistical analysis was carried out by using SPSS software, version 19.0. Results: All GBS were susceptible to benzylpenicillin, ampicillin, quinupristin/dalfopristin, tigecycline, linezolid and vancomycin, but a considerable proportion was resistant to clindamycin (29.67%), erythromycin (46.15%)， azithromycin (63.74%), tetracycline (84.62%) and quinolones (25.27%). The carrier rates of ermB (69.04%) and mefA/E (64.28%) were detected in these GBS strains resistant to erythromycin. In terms of MLVA detection, 91 GBS strains were categorized into 43 genotypes and 6 clusters. All GBS harboured hylB and cylE genes, most of which carried a combination of PI-1 and PI-2a genes as a common virulence gene profile. Conclusions: The high level of resistance conferred by some corresponding resistance genes to macrolides, lincosamides and quinolones of GBS isolates from pregnant women in southern China, has reinforced the necessity for monitoring GBS strain resistance to the above agents. Comparative genetic studies of GBS isolates, especially efforts to understand the relationship between pilus islands and genotype, were essential for conducting infection control and epidemiological comparisons between countries.

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.

PCR characterization and typing of Klebsiella pneumoniae using capsular type-specific, variable number tandem repeat and virulence gene targets

2010 ◽  
Vol 59 (5) ◽  
pp. 541-547 ◽  
Author(s):  
Jane F. Turton ◽  
Claire Perry ◽  
Suzanne Elgohari ◽  
Catherine V. Hampton
Keyword(s):  
Klebsiella Pneumoniae ◽  
Nosocomial Infection ◽  
Tandem Repeat ◽  
Internal Transcribed Spacer ◽  
Variable Number Tandem Repeat ◽  
Virulence Gene ◽  
Invasive Disease ◽  
Variable Number ◽  
Capsular Type ◽  
Liver Abscesses

A multiplex PCR is described which detects capsular types K1, K2, K5, K54 and K57, which are those most associated with invasive disease or pathogenicity, a further capsular type (K20), two putative virulence factors (rmpA and wcaG) and the 16S–23S internal transcribed spacer unit of Klebsiella pneumoniae, facilitating identification of this organism. wcaG encodes capsular fucose production and was associated with capsular types K1 and K54, but was also found in strains of other capsular types; 18 of the 543 isolates screened were PCR-positive for this gene. An eight-locus variable number tandem repeat (VNTR) scheme was designed, which provided discrimination at a level similar to that afforded by PFGE among a panel of 36 isolates representing 29 PFGE types. All isolates tested of the virulent K1 clone of CC23, associated with pyogenic liver abscesses, shared the same VNTR profile, which may be helpful in identifying this clone; such isolates were also PCR-positive for allS. These methods provide a rapid means of characterizing and typing isolates of this important agent of community-acquired and nosocomial infection.

scholarly journals Molecular typing and antimicrobial resistance profiling of 33 mastitis-related Staphylococcus aureus isolates from cows in the Comarca Lagunera region of Mexico

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Y. Mora-Hernández ◽  
E. Vera Murguía ◽  
J. Stinenbosch ◽  
P. Hernández Jauregui ◽  
Jan Maarten van Dijl ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Susceptibility Testing ◽  
Protein A ◽  
Variable Number Tandem Repeat ◽  
Variable Number ◽  
Economic Losses ◽  
Small Plasmid ◽  
High Prevalence ◽  
The Masses

AbstractMastitis in cows is a major cause of economic losses and it is commonly associated with Staphylococcus aureus. Little is known about the S. aureus lineages causing mastitis in Mexican cattle. The aim of this study was to type S. aureus isolates causing mastitis in cows from the Comarca Lagunera region in Mexico in 2015–2016. Multi-locus variable number tandem repeat fingerprinting (MLVF) of 33 S. aureus isolates obtained from 210 milk samples revealed the MLVF clusters A (n = 1), B (n = 26), C (n = 5) and D (n = 1). Spa-typing showed that clusters A and B represent the spa-type t224, cluster C includes spa-types t3196 and t416, and cluster D represents spa-type t114. The different spa-types were mirrored by the masses of protein A bands as detected by Western blotting. Antimicrobial susceptibility testing showed that one isolate was susceptible to all antimicrobials tested, whereas all other strains were resistant only to benzylpenicillin. These findings show that only four S. aureus lineages, susceptible to most antimicrobials, were responsible for causing mastitis at the time of sampling. Lastly, many isolates carried the same small plasmid, designated pSAM1. The high prevalence of pSAM1 amongst the antimicrobial-susceptible isolates suggests an association with bovine colonization or mastitis rather than antimicrobial resistance.

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