Decrease in antibiotic resistance of Streptococcus pneumoniae between 2003 and 2009 in France and changes in serotype distribution: Ongoing survey of the French Pneumococcus Surveillance Network

Background: The French regional pneumococcal observatories (ORP) network was created in 1995, it participates to the close monitoring of the trends in antimicrobial resistance and serotype distribution with the National Reference Centre for Pneumococci (NRCP) and the Institut de Veille Sanitaire (InVS). The aim of this survey was to assess the antibiotic resistance and the distribution of vaccine and non-vaccine serotypes in invasive pneumococcal disease (IPD) in adults and children as well in otitis in children in France in 2009. Methods: Antimicrobial susceptibility testing was performed on 5,194 isolates of S. pneumoniae recovered from cerebrospinal fluid (CSF), blood, middle ear fluid (MEF) and pleural fluid during the year 2009 by the 23 ORP. MICs of penicillin (P), amoxicillin (AMX) and cefotaxime (CTX) were determined by the agar dilution method and interpreted according to the Antibiotics Comity of the French Society of Microbiology breakpoints. Serotyping was performed at the NRCP with serotype-specific antisera, by latex agglutination test. Results: Results of susceptibility between 2003 and 2009 to P are presented in Table 1. The pneumococci with decreased susceptibility to penicillin G (PDSP) decreased significantly in all types of samples except for MEF’s isolates in children between 2007 and 2009. In the global population, the percentage of I+R (2003 vs 2009) decreased significantly for AMX (30.3% versus 9.6%) and for CTX (18.2% versus 10.5%). Strains highly resistant (MIC > 2 mg/L) remained rare: 0.4%, 1.1% and 0.2% for P, AMX and CTX respectively. The most frequent capsular types in CSF were 3, 7F, 19A, 6C, 23B for adults and 7F, 19A, 3, 33F and 15B for children. Serotypes included in the PCV-7 and PCV-13 vaccine accounted in children for 4% and 51% respectively and in adults for 12% and 48% respectively. By contrast, the serotype 19A remained highly predominant (80%) among MEF isolates. Conclusions: We observed a significant decrease of PDSP between 2003 and 2009 (50.2 to 33.0%). The decrease coincided with the introduction of PCV7 and with a general reduction in levels of antibiotic consumption in France. This continuous survey is necessary to underline modification in serotype distribution in France after PVC13 introduction (June 2010)

Diminution de la résistance aux antibiotiques des souches de Streptococcus pneumoniae isolées d’infections invasives en France entre 2005 et 2011 : résultats des Observatoires Régionaux du Pneumocoque (ORP)

National audienc

Staphylococcal Panton-Valentine Leucocidin as a Major Virulence Factor Associated to Furuncles

Panton-Valentine Leucocidin (PVL), one of the β-barrel pore-forming staphylococcal leucotoxins, is known to be associated to furuncles and some severe community pneumonia. However, it is still uncertain how many other virulence factors are also associated to furuncles and what the risk factors of furuncles are in immuno-compromised status of patients, especially the HIV (+) patients. In this paper, we use antigen immunoprecipitation and multiplex PCR approach to determine the presence of 19 toxins, 8 adhesion factors and the PFGE profiles associated to furuncles in three independent patient study groups of S. aureus (SA) isolates collected from the Cayenne General Hospital (French Guiana). The patient groups were made of: 16 isolates from HIV (−) patients, 9 from HIV (+) patients suffering from furuncles, and 30 control isolates from patients with diverse secondary infected dermatitis. Our data reveals that the majority (96%) of SA strains isolated from HIV patient-derived furuncles significantly produced PVL (p<10−7), whereas only 10% of SA strains produced this toxin in secondary infected dermatosis. A high prevalence of LukE-LukD-producing isolates (56 to 78%) was recorded in patient groups. Genes encoding clumping factor B, collagen- and laminin-binding proteins (clfB, cna, lbp, respectively) were markedly frequent (30 to 55%), without being associated to a specific group. Pulse field gel electrophoresis evidenced 24 overall pulsotypes, whereas the 25 PVL-producing isolates were distributed into 15 non clonal fingerprints. These pulsotypes were not specific PVL-producing isolates. PVL appears to be the major virulence factor associated to furuncles in Europe and in South America regardless of the immune status of the HIV patients

Association of Panton Valentine Leukocidin (PVL) genes with methicillin resistant Staphylococcus aureus (MRSA) in Western Nepal: a matter of concern for community infections (a hospital based prospective study)

BACKGROUND: Methicillin resistant Staphylococcus aureus (MRSA) is a major human pathogen associated with nosocomial and community infections. Panton Valentine leukocidin (PVL) is considered one of the important virulence factors of S. aureus responsible for destruction of white blood cells, necrosis and apoptosis and as a marker of community acquired MRSA. This study was aimed to determine the prevalence of PVL genes among MRSA isolates and to check the reliability of PVL as marker of community acquired MRSA isolates from Western Nepal. METHODS: A total of 400 strains of S. aureus were collected from clinical specimens and various units (Operation Theater, Intensive Care Units) of the hospital and 139 of these had been confirmed as MRSA by previous study. Multiplex PCR was used to detect mecA and PVL genes. Clinical data as well as antimicrobial susceptibility data was analyzed and compared among PVL positive and negative MRSA isolates. RESULTS: Out of 139 MRSA isolates, 79 (56.8 %) were PVL positive. The majority of the community acquired MRSA (90.4 %) were PVL positive (Positive predictive value: 94.9 % and negative predictive value: 86.6 %), while PVL was detected only in 4 (7.1 %) hospital associated MRSA strains. None of the MRSA isolates from hospital environment was found positive for the PVL genes. The majority of the PVL positive strains (75.5 %) were isolated from pus samples. Antibiotic resistance among PVL negative MRSA isolates was found higher as compared to PVL positive MRSA. CONCLUSION: Our study showed high prevalence of PVL among community acquired MRSA isolates. Absence of PVL among MRSA isolates from hospital environment indicates its poor association with hospital acquired MRSA and therefore, PVL may be used a marker for community acquired MRSA. This is first study from Nepal, to test PVL among MRSA isolates from hospital environment. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12879-016-1531-1) contains supplementary material, which is available to authorized users

Intestinal carriage of Staphylococcus aureus: How does its frequency compare with that of nasal carriage and what is its clinical impact?

The bacterial species Staphylococcus aureus, including its methicillin-resistant variant (MRSA), finds its primary ecological niche in the human nose, but is also able to colonize the intestines and the perineal region. Intestinal carriage has not been widely investigated despite its potential clinical impact. This review summarizes literature on the topic and sketches the current state of affairs from a microbiological and infectious diseases' perspective. Major findings are that the average reported detection rate of intestinal carriage in healthy individuals and patients is 20% for S. aureus and 9% for MRSA, which is approximately half of that for nasal carriage. Nasal carriage seems to predispose to intestinal carriage, but sole intestinal carriage occurs relatively frequently and is observed in 1 out of 3 intestinal carriers, which provides a rationale to include intestinal screening for surveillance or in outbreak settings. Colonization of the intestinal tract with S. aureus at a young age occurs at a high frequency and may affect the host's immune system. The frequency of intestinal carriage is generally underestimated and may significantly contribute to bacterial dissemination and subsequent risk of infections. Whether intestinal rather than nasal S. aureus carriage is a primary predictor for infections is still ill-defined