Emergence of Ciprofloxacin-Nonsusceptible
            <i>Streptococcus pyogenes</i>
            Isolates from Healthy Children and Pediatric Patients in Portugal

Pires, Renato; Ardanuy, Carmen; Rolo, Dora; Morais, Ana Jessyca Alves; Brito-Avô, António; Gonçalo-Marques, José; Liñares, Josefina; Sanches, Ilda Santos

doi:10.1128/aac.01536-09

Cited by 17 publications

(8 citation statements)

References 26 publications

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“…We argue that the presence of G. vaginalis in healthy individuals does not constitute a basis for disregarding this bacterium in the causes and complications of BV. Just as “healthy” people can be asymptomatic carriers of such pathogens as Streptococcus pneumoniae [98], Group A Streptococcus [99], [100], Haemophilus influenzae [98] or Clostridium difficile [101], carrier states may also exist for G. vaginalis. Indeed, recent genomic and phenotypic studies support the hypothesis that variations in bacterial strain virulence, titers, and/or windows of host susceptibility may bring a colonization state to a state of pathogenesis [38], [88], [91], [102], [103].…”

Section: Discussionmentioning

confidence: 99%

Clinical Features of Bacterial Vaginosis in a Murine Model of Vaginal Infection with Gardnerella vaginalis

2013

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Bacterial vaginosis (BV) is a dysbiosis of the vaginal flora characterized by a shift from a Lactobacillus-dominant environment to a polymicrobial mixture including Actinobacteria and Gram-negative bacilli. BV is a common vaginal condition in women and is associated with increased risk of sexually transmitted infection and adverse pregnancy outcomes such as preterm birth. Gardnerella vaginalis is one of the most frequently isolated bacterial species in BV. However, there has been much debate in the literature concerning the contribution of G. vaginalis to the etiology of BV, since it is also present in a significant proportion of healthy women. Here we present a new murine vaginal infection model with a clinical isolate of G. vaginalis. Our data demonstrate that this model displays key features used clinically to diagnose BV, including the presence of sialidase activity and exfoliated epithelial cells with adherent bacteria (reminiscent of clue cells). G. vaginalis was capable of ascending uterine infection, which correlated with the degree of vaginal infection and level of vaginal sialidase activity. The host response to G. vaginalis infection was characterized by robust vaginal epithelial cell exfoliation in the absence of histological inflammation. Our analyses of clinical specimens from women with BV revealed a measureable epithelial exfoliation response compared to women with normal flora, a phenotype that, to our knowledge, is measured here for the first time. The results of this study demonstrate that G. vaginalis is sufficient to cause BV phenotypes and suggest that this organism may contribute to BV etiology and associated complications. This is the first time vaginal infection by a BV associated bacterium in an animal has been shown to parallel the human disease with regard to clinical diagnostic features. Future studies with this model should facilitate investigation of important questions regarding BV etiology, pathogenesis and associated complications.

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Section: Discussionmentioning

confidence: 99%

Clinical Features of Bacterial Vaginosis in a Murine Model of Vaginal Infection with Gardnerella vaginalis

2013

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“…Drug-resistant isolates of bacteria were detected even in remote mountainous areas of Amazon where antibiotics have never been used [ 4 ]. Presence of drug-resistant isolates in children might be attributed to their increased contact with adults and playmates in families, daycare, or school settings [ 21 , 22 ]. Among the environmental factors, food supply chain may be the major source of antibiotic resistance in “naïve” humans as an indirect consequence of overuse of antibiotics for curative and preventative purpose in stock farming and agricultural products.…”

Section: Discussionmentioning

confidence: 99%

Comparative Analysis of Quinolone Resistance in Clinical Isolates ofKlebsiella pneumoniaeandEscherichia colifrom Chinese Children and Adults

Huang

Ogutu

et al. 2015

BioMed Research International

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The objective of this study was to compare quinolone resistance and gyrA mutations in clinical isolates of Klebsiella pneumoniae and Escherichia coli from Chinese adults who used quinolone in the preceding month and children without any known history of quinolone administration. The antimicrobial susceptibilities of 61 isolates from children and 79 isolates from adults were determined. The mutations in the quinolone resistance-determining regions in gyrA gene were detected by PCR and DNA sequencing. Fluoroquinolone resistance and types of gyrA mutations in isolates from children and adults were compared and statistically analyzed. No significant differences were detected in the resistance rates of ciprofloxacin and levofloxacin between children and adults among isolates of the two species (all P > 0.05). The double mutation Ser83→Leu + Asp87→Asn in the ciprofloxacin-resistant isolates occurred in 73.7% isolates from the children and 67.9% from the adults, respectively (P = 0.5444). Children with no known history of quinolone administration were found to carry fluoroquinolone-resistant Enterobacteriaceae isolates. The occurrence of ciprofloxacin resistance and the major types of gyrA mutations in the isolates from the children were similar to those from adults. The results indicate that precautions should be taken on environmental issues resulting from widespread transmission of quinolone resistance.

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“…Fluoroquinolone resistance has recently emerged among S. pyogenes , due to mutations in the parC and/or gyrA locus. A highly prevalent, nonsusceptible emm6 /ST382 clone was identified in numerous studies in many parts of the world, although most isolates appear to have low‐level resistance (Alonso et al ., 2005; Orscheln et al ., 2005; Powis et al ., 2005; Yan et al ., 2008; Malhotra‐Kumar et al ., 2009; Smeesters et al ., 2009; Montes et al ., 2010; Pires et al ., 2010). Other emm types associated with fluoroquinolone resistance include emm1, emm5, emm28, emm75 and emm89 .…”

Section: Phylogeography Of Antibiotic‐resistant S Pyogenes Clonesmentioning

confidence: 99%

Population biology of Gram-positive pathogens: high-risk clones for dissemination of antibiotic resistance

et al. 2011

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Infections caused by multi-resistant Gram positive bacteria represent a major health burden in the community as well as in hospitalized patients. Staphylococcus aureus, Enterococcus faecalis and Enterococcus faecium are well-known pathogens of hospitalized patients, frequently linked with resistance against multiple antibiotics, compromising effective therapy. Streptococcus pneumoniae and Streptococcus pyogenes are important pathogens in the community and S. aureus has recently emerged as an important community-acquired pathogen. Population genetic studies reveal that recombination prevails as a driving force of genetic diversity in E. faecium, E. faecalis, S. pneumoniae, and S. pyogenes and thus, these species are weakly clonal. Although recombination has a relatively modest role driving the genetic variation of the core genome of S. aureus, the horizontal acquistion of resistance and virulence genes plays a key role in the emergence of new clinically relevant clones in this species. In this review we discuss the population genetics of E. faecium, E. faecalis, S. pneumoniae, S. pyogenes, and S. aureus. Knowledge of the population structure of these pathogens is not only highly relevant for (molecular) epidemiological research but also for identifying the genetic variation that underlies changes in clinical behaviour, to improve our understanding of the pathogenic behaviour of particular clones and to identify novel targets for vaccines or immunotherapy.

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Emergence of Ciprofloxacin-Nonsusceptible Streptococcus pyogenes Isolates from Healthy Children and Pediatric Patients in Portugal

Cited by 17 publications

References 26 publications

Clinical Features of Bacterial Vaginosis in a Murine Model of Vaginal Infection with Gardnerella vaginalis

Clinical Features of Bacterial Vaginosis in a Murine Model of Vaginal Infection with Gardnerella vaginalis

Comparative Analysis of Quinolone Resistance in Clinical Isolates ofKlebsiella pneumoniaeandEscherichia colifrom Chinese Children and Adults

Population biology of Gram-positive pathogens: high-risk clones for dissemination of antibiotic resistance

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