Skin and soft tissue infections (SSTIs) caused by mupirocin-resistant Staphylococcus aureus strains have recently increased in number in our settings. We sought to evaluate the characteristics of these cases over a 43-month period. Data for all community-acquired staphylococcal infections caused by mupirocin-resistant strains were retrospectively reviewed. Genes encoding products producing high-level resistance (HLR) to mupirocin (mupA), fusidic acid resistance (fusB), resistance to macrolides and lincosamides (ermC and ermA), Panton-Valentine leukocidin (PVL) (lukS/lukF-PV), exfoliative toxins (eta and etb), and fibronectin binding protein A (fnbA) were investigated by PCRs in 102 selected preserved strains. Genotyping was performed by SCCmec and agr typing, whereas clonality was determined by pulsedfield gel electrophoresis (PFGE) and multilocus sequence typing (MLST). A total of 437 cases among 2,137 staphylococcal infections were recorded in 2013 to 2016; they were all SSTIs with the exception of 1 case of primary bacteremia. Impetigo was the predominant clinical entity (371 cases [84.9%]), followed by staphylococcal scalded skin syndrome (21 cases [4.8%]), and there were no abscesses. The number of infections detected annually increased during the study years. All except 3 isolates were methicillin susceptible. The rates of HLR to mupirocin and constitutive resistance to clindamycin were 99% and 20.1%, respectively. Among the 102 tested strains, 100 (98%) were mupA positive and 97 (95%) were fusB positive, 26/27 clindamycin-resistant strains (96.3%) were ermA positive, 83 strains (81.4%) were lukS/lukF positive, 95 (93%) carried both eta and etb genes, and 99 (97%) were fnbA positive. Genotyping of methicillin-sensitive S. aureus (MSSA) strains revealed that 96/99 (96.7%) belonged to one main pulsotype, pulsotype 1, classified as sequence type 121 (ST121). The emergence of a single MSSA clone (ST121) causing impetigo was documented. Resistance to topical antimicrobials and a rich toxinogenic profile confer to this clone adaptability for spread in the community.

Coagulase-negative staphylococci (CNS), especially Staphylococcus epidermidis and Staphylococcus haemolyticus, have emerged as opportunistic pathogens in immunocompromised patients and those with indwelling medical devices. In this study, CNS recovered from patients with bloodstream infections (BSIs) or prosthetic-device-associated infections (PDAIs) were compared in terms of biofilm formation, antimicrobial resistance, clonal distribution, and carriage of adhesin and toxin genes. A total of 226 CNS isolates (168 S. epidermidis and 58 S. haemolyticus) recovered from hospital inpatients with BSIs (100 isolates) or PDAIs (126 isolates) were tested for biofilm formation, antimicrobial susceptibility, and mecA, ica operon, adhesin (aap, bap, fnbA, atlE, fbe) and toxin (tst, sea, sec) genes. The selected CNS were classified into pulsotypes by PFGE and assigned to sequence types by multilocus sequence typing. In total, 106/226 isolates (46.9 %) produced biofilm, whereas 150 (66.4 %) carried the ica operon. Most isolates carried mecA and were multidrug resistant (90.7 %). CNS recovered from BSIs were significantly more likely to produce biofilm (P50.003), be resistant to antimicrobials and carry mecA (P,0.001), as compared with isolates derived from PDAIs. CNS from PDAIs were more likely to carry the aap and bap genes (P50.006 and P50.045, respectively). No significant differences in the carriage of toxin genes were identified (P.0.05). Although PFGE revealed genetic diversity, especially among S. epidermidis, analysis of representative strains from the main PFGE types by multilocus sequence typing revealed three major clones (ST2, ST5 and ST16). A clonal relationship was found with respect to antimicrobial susceptibility and ica and aap gene carriage, reinforcing the premise of clonal expansion in hospital settings. The results of this 3Present address: Central Veterinary Institute of Wageningen UR, Lelystad, the Netherlands.

This original prospective multicentre study highlights stark differences in European MRSA epidemiology compared with the USA, and that the USA300 CA-MRSA clone is not predominant among community-infected patients in Europe.

No abstract

An atypical pattern of coagulase-negative staphylococcal (CoNS) sepsis, characterized by persistence despite aggressive antibiotic therapy, has been described in neonates cared for in neonatal intensive-care units. Our aim was to analyse the clinical, microbiological and molecular determinants of this persistent CoNS bacteraemia. Neonates with late-onset CoNS bacteraemia were studied for a 2-year period. Demographic, clinical, laboratory, microbiological and molecular data were compared between neonates with persistent (≥3 consecutive positive blood cultures) and non-persistent CoNS bacteraemia. Twenty-nine infants with persistent and 43 with non-persistent bacteraemia were identified, with no significant differences regarding demographic and clinical characteristics between the two groups. Of a total of 170 CoNS isolates, 80 showed biofilm production (54 persistent and 26 non-persistent; p 0.013), whereas 127 were positive for the icaA and icaD genes (74 persistent and 53 non-persistent; p 0.598). Sixty ica-positive isolates did not produce slime, whereas 13 ica-negative isolates showed biofilm production. Endotracheal intubation and the presence of central vascular catheters were significant risk factors for persistent bacteraemia, but, in a logistic regression model, only biofilm production was significantly related to the persistent form of the disease (p 0.005). In this study, persistent CoNS sepsis in neonates requiring intensive care was not related to most of the known clinical risk factors, and it was associated with severe thrombocytopenia. Isolates associated with persistent bacteraemia were more likely to produce biofilm, independently of the presence of the ica operon.

No abstract

Staphylococcus lugdunensis has emerged as a significant human pathogen, with distinct clinical and microbiological characteristics. Our goal was to identify the virulence factors in S. lugdunensis recovered from infected patients of two Greek hospitals during a six-year period (2008-2013). A collection of 38 S. lugdunensis was tested for biofilm formation, antimicrobial susceptibility, clonal distribution, virulence factors (ica operon, fbl, atlL, vwbl, slush) and antibiotic resistance genes (mecA, ermC) carriage. Strains were classified into pulsotypes by pulsed-field gel electrophoresis (PFGE) of SmaI DNA digests. The majority (22) was isolated from skin and soft tissue infections (SSTIs), nine from deep-sited infections (DSIs), including three bacteraemias and seven from prosthetic device-associated infections (PDAIs). All isolates were oxacillin-susceptible, mecA-negative and fbl-positive. The highest resistance rate was detected for ampicillin (50%), followed by erythromycin and clindamycin (18.4%). Fourteen isolates (36.8%) produced biofilm, whereas 26/38 (68.4%) carried the ica operon. Biofilm formation was more frequent in isolates from PDAIs. Thirty-six strains (94.7%) carried atlL and 31 (81.6%) carried vwbl, whereas slush was detected in 15 (39.5%). PFGE revealed a low level of genetic diversity: strains were classified into seven pulsotypes, with two major clones (C: 22 and D: nine strains). Type C strains recovered from all infection sites prevailed in biofilm formation and ermC carriage, whereas type D strains associated with SSTIs and DSIs carried more frequently vwbl, slush or both genes. Despite susceptibility to antimicrobials, the clonal expansion and carriage of virulence factors, combined with biofilm-producing ability, render this species an important pathogen that should not be ignored.

This study investigated genetic relatedness among Staphylococcus aureus from livestock, their carcass’ surfaces after slaughter, personnel, and equipment of a Greek abattoir. Genotyping was performed using PFGE, MLST, spa, and SCCmec. Antimicrobial susceptibility was determined according to EUCAST guidelines. Genes encoding staphylococcal enterotoxins (SEs) and Panton‐Valentine leukocidin (PVL) were detected by PCRs. From 392 samples, 46 S. aureus were recovered, 10 from workers, 6 from animals, 10 from carcass’, and 20 from equipment’s surfaces. Resistance to tetracycline was 80.4%, whereas, 58.7% of isolates were multi‐drug resistant. Eleven isolates (23.9%) were MRSA, 8 mecA‐ and 3 mecC‐positive. Fifteen PFGE and 13 spa types were identified, classified in 10 sequence types (STs). ST80 predominated among MSSA, and ST88‐IV clone among MRSA. Fifteen strains (32.6%) carried enterotoxin genes 7 of them possessed also the PVL genes. The abattoir seems to play important role in the transmission of S. aureus between animals and humans. Practical applications Antibiotic susceptibility, clonality, and toxin profiles among Staphylococcus aureus recovered from humans, animals, resulting carcasses and environmental surfaces of an abattoir were assessed. Our results showed spread of multi‐resistant toxigenic strains belonging to human and animals’ origin clones, indicating that the abattoir might be the reservoir for their transmission with potential negative impact on consumers’ health. The establishment and implementation of strict hygiene rules in the farms and during the slaughtering process in the abattoirs could control spread of virulent S. aureus strains.