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Bacteriophages represent the most extensive group of viruses within the human virome and have a significant impact on general health and well-being by regulating bacterial population dynamics. Staphylococcus aureus , found in the anterior nostrils, throat and skin, is an opportunistic pathobiont that can cause a wide range of diseases, from chronic inflammation to severe and acute infections. In this study, we developed a human cell-based homeostasis model between a clinically isolated strain of S. aureus 141 and active phages for this strain (PYOSa141) isolated from the commercial Pyophage cocktail (PYO). The cocktail is produced by Eliava BioPreparations Ltd. (Tbilisi, Georgia) and is used as an add-on therapy for bacterial infections, mainly in Georgia. The triptych interaction model was evaluated by time-dependent analysis of cell death and inflammatory response of the nasal and bronchial epithelial cells. Inflammatory mediators (IL-8, CCL5/RANTES, IL-6 and IL-1β) in the culture supernatants were measured by enzyme-linked immunosorbent assay and cell viability was determined by crystal violet staining. By measuring trans-epithelial electrical resistance, we assessed the epithelial integrity of nasal cells that had differentiated under air-liquid interface conditions. PYOSa141 was found to have a prophylactic effect on airway epithelial cells exposed to S. aureus 141 by effectively down-regulating bacterial-induced inflammation, cell death and epithelial barrier disruption in a time-dependent manner. Overall, the proposed model represents an advance in the way multi-component biological systems can be simulated in vitro.

Background: Identifying potential predictive factors for the type of bacteremia (Gram-negative vs. Gram-positive) in children with cancer would be crucial for the timely selection of the appropriate empiric antibiotic treatment. Materials and Methods: Demographic, clinical, and laboratory characteristics of children with cancer and a bacterial bloodstream infection (BSI) (February 1, 2011 to February 28, 2018) in a tertiary pediatric oncology department were retrospectively examined and were correlated with the type of isolated bacteria. Results: Among 224 monomicrobial bacterial BSI episodes, Gram-negative and Gram-positive bacteria were isolated in 110 and 114 episodes, respectively. Gram-negative bacteria were isolated significantly more frequently in girls (Gram-negative/Gram-positive ratio 1.7:1) versus boys (Gram-negative/Gram-positive ratio 0.72:1), P=0.002, in patients with previous BSI episodes (1.4:1) versus those without (0.8:1), P=0.042, and in children with hematologic malignancy (1.3:1) versus those who suffered from solid tumors (0.52:1), P=0.003. Gram-negative BSI episodes were more frequently correlated with a lower count of leukocytes, P=0.009, neutrophils, P=0.009 and platelets, P=0.002, but with significantly higher C-reactive protein (CRP) levels, P=0.049. Female sex, hematologic malignancy, and higher CRP levels remained independent risk factors for Gram-negative BSI in the multivariate analysis. Among neutropenic patients, boys with solid tumors and a recent central venous catheter placement appear to be at increased risk for Gram-positive BSI in the multivariate analysis. Conclusions: Although Gram-negative and Gram-positive BSIs are close to balance in children with cancer, Gram-negative bacteria are more likely to be isolated in girls, children with hematologic malignancies and those with higher CRP level at admission. In contrast, neutropenic boys with solid tumors and a recently placed central venous catheter may be at increased risk for Gram-positive BSI indicating probably the need for initially adding antibiotics targeting Gram-positive bacteria.

Background: Staphylococcus aureus is a common pathogen causing hospital acquired infections (HAIs) in neonates. In this study, the epidemiology of methicillin-resistant S. aureus (MRSA) colonization and infections in a 30-bed, level III university-affiliated neonatal intensive care unit (NICU) located in a children’s hospital was retrospectively investigated for the period 2014-2018. Methods: Genes encoding Panton-Valentine Leukocidin (lukS/lukF-PV, PVL), toxic shock syndrome toxin (tst), exfoliative toxins (eta, etb), and the resistance genes mecA, mecC and fusB, were defined in 46 representative strains by PCRs. Relatedness of strains was assessed by MLST. Results: Of 1538 neonates, 77 (5%) had a positive culture for MRSA (23/77 were NICU-acquired and 54/77 imported cases). Four MRSA bacteremias occurred. Most isolates were multi-resistant. One major clone was identified, ST225, among 40 tested neonatal strains (23/40, 58%). Of these, 14/23 were imported from the same maternity hospital (MH). Another clone, ST217, was predominant (4/6) among health care workers (HCWs), found colonized. Four isolates classified as ST80 were PVL-positive. Additional four strains carried tst (10%), belonging to ST30 and ST225 (two strains each), and two etb. The implicated MH was notified for the problem, decolonization treatment was successfully performed in HCWs and neonates. Strengthening of infection control measures with emphasis on hand hygiene was applied. Conclusions: Uncovering reservoirs for on-going MRSA transmission in NICUs has proved challenging. Well known nosocomial MRSA clones are being constantly introduced and transmitted via MHs and HCWs. Effective infection prevention and control requires constant vigilance.

Background Staphylococcus aureus causes various infections, including skin and soft tissue infections (SSTIs). In this study, methicillin-susceptible S. aureus (MSSA) from SSTIs among patients in three tertiary-care hospitals in Greece were studied in terms of antimicrobial resistance, clonal distribution, toxin and adhesin genes carriage. Results During a five-year period (2014–2018), 6145 S. aureus were recovered from 13,244 patients with SSTIs and tested for antimicrobial susceptibility. MSSA were 4806 (78.21 %) including 1484 isolates with mupirocin minimum inhibitory concentration (MIC) > 64 mg/L (30.88 %). Two hundred and sixty representative mupirocin-resistant MSSA were analyzed for genes encoding Panton-Valentine leukocidin (PVL, lukS/lukF-PV), exfoliative toxins (eta, etb), adhesin FnbA (fnbA) and resistance genes mupA (high-level resistance to mupirocin), fusB (fusidic acid), aminoglycosides’ modifying enzymes, ermA, ermC and msrA (macrolides/lincosamides) by PCRs. Strains were classified into clones by PFGE and MLST. All mupirocin-resistant MSSA were penicillin-resistant; 92.7 % expressed resistance to fusidic acid and 88.9 % to tobramycin. All 260 molecularly analyzed isolates were mupA-positive; all fusidic acid-resistant (241/260) carried fusB whereas, the tobramycin-resistant ones (230), ant(4′)-Ia. The majority carried eta (93.85 %), etb (98.08 %) and fnbA (88.85 %). PFGE typing revealed a mostly unvarying population; 260 MSSA were grouped into three types. One major eta/etb-positive clone comprising of 258/260 strains (99.2 %), PFGE type 1, was classified as ST121, including nine strains co-carrying PVL. Another PVL-positive strain was identified as ST1, and one toxins-negative as ST21. Conclusions A mupirocin-resistant MSSA clone, ST121, carrying resistance, exfoliative toxins and adhesin genes, was spread and predominated in SSTIs from patients in Greece during the five-year studied period.

Background Staphylococcus aureus is a common pathogen causing hospital acquired infections (HAIs) in neonates. In this study, the epidemiology of methicillin-resistant S. aureus (MRSA) colonization and infections in a 30-bed, level III university-affiliated neonatal intensive care unit (NICU) located in a children's hospital was retrospectively investigated for the period 2014–2018. Methods Genes encoding Panton-Valentine Leukocidin (lukS/lukF-PV, PVL), toxic shock syndrome toxin (tst), exfoliative toxins (eta, etb), and the resistance genes mecA, mecC and fusB, were defined in 46 representative strains by PCRs. Relatedness of strains was assessed by MLST. Results Of 1538 neonates, 77 (5%) had a positive culture for MRSA (23/77 were NICU-acquired and 54/77 imported cases). Four MRSA bacteremias occurred. Most isolates were multi-resistant. One major clone was identified, ST225, among 40 tested neonatal strains (23/40, 58%). Of these, 14/23 were imported from the same maternity hospital (MH). Another clone, ST217, was predominant (4/6) among health care workers (HCWs), found colonized. Four isolates classified as ST80 were PVL-positive. Additional four strains carried tst (10%), belonging to ST30 and ST225 (two strains each), and two etb. The implicated MH was notified for the problem, decolonization treatment was successfully performed in HCWs and neonates. Strengthening of infection control measures with emphasis on hand hygiene was applied. Conclusions Uncovering reservoirs for on-going MRSA transmission in NICUs has proved challenging. Well known nosocomial MRSA clones are being constantly introduced and transmitted via MHs and HCWs. Effective infection prevention and control requires constant vigilance.

BACKGROUND Identifying potential predictive factors for the type of bacteremia (Gram-negative vs. Gram-positive) in children with cancer would be crucial for the timely selection of the appropriate empiric antibiotic treatment. MATERIALS AND METHODS Demographic, clinical, and laboratory characteristics of children with cancer and a bacterial bloodstream infection (BSI) (February 1, 2011 to February 28, 2018) in a tertiary pediatric oncology department were retrospectively examined and were correlated with the type of isolated bacteria. RESULTS Among 224 monomicrobial bacterial BSI episodes, Gram-negative and Gram-positive bacteria were isolated in 110 and 114 episodes, respectively. Gram-negative bacteria were isolated significantly more frequently in girls (Gram-negative/Gram-positive ratio 1.7:1) versus boys (Gram-negative/Gram-positive ratio 0.72:1), P=0.002, in patients with previous BSI episodes (1.4:1) versus those without (0.8:1), P=0.042, and in children with hematologic malignancy (1.3:1) versus those who suffered from solid tumors (0.52:1), P=0.003. Gram-negative BSI episodes were more frequently correlated with a lower count of leukocytes, P=0.009, neutrophils, P=0.009 and platelets, P=0.002, but with significantly higher C-reactive protein (CRP) levels, P=0.049. Female sex, hematologic malignancy, and higher CRP levels remained independent risk factors for Gram-negative BSI in the multivariate analysis. Among neutropenic patients, boys with solid tumors and a recent central venous catheter placement appear to be at increased risk for Gram-positive BSI in the multivariate analysis. CONCLUSIONS Although Gram-negative and Gram-positive BSIs are close to balance in children with cancer, Gram-negative bacteria are more likely to be isolated in girls, children with hematologic malignancies and those with higher CRP level at admission. In contrast, neutropenic boys with solid tumors and a recently placed central venous catheter may be at increased risk for Gram-positive BSI indicating probably the need for initially adding antibiotics targeting Gram-positive bacteria.

Additional file 1: Supplementary Figure 1: PFGE of S. aureus after DNA digestion with SmaI.

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 SCC mec and agr typing, whereas clonality was determined by pulsed-field 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.

Introduction of treatment and systematic vaccination has significantly reduced diphtheria mortality, however toxigenic strains continue to circulate worldwide. The emergence of an indigenous diphtheria case with fatal outcome in Greece, after 30 years, raised challenges for laboratory confirmation, clinical and public health management. Toxigenic Corynebacterium diphtheriae was isolated from an incompletely vaccinated 8-year-old boy with underlying conditions. The child passed away due to respiratory distress syndrome, before administration of diphtheria antitoxin (DAT). All close contacts in family, school and hospital settings were investigated. Pharyngeal swabs were obtained to determine asymptomatic carriage. Chemoprophylaxis was given for 7 days to all close contacts and a booster dose to those incompletely vaccinated. Testing revealed a classmate, belonging to a subpopulation group (Roma), and incompletely vaccinated, as an asymptomatic carrier with an indistinguishable toxigenic strain (same novel multilocus sequence type, designated ST698). This case highlights the role of asymptomatic carriage, as entry of toxigenic strains into susceptible populations can put individuals and their environment at risk. Maintenance of high-level epidemiological and microbiological surveillance, implementation of systematic vaccination in children and adults with primary and booster doses, availability of a DAT stockpile, allowing timely administration, are the cornerstone to prevent similar incidents in the future. © 2020 Cambridge University Press. All rights reserved.

A sharp increase in staphylococcal scalded skin syndrome (SSSS) cases has been recorded in our settings since 2015, with 31 cases having been documented during the period 2014–2017. The molecular investigation of strains from the above period showed the emergence of a methicillin-susceptible, mupirocin-and fusidic acid-resistant Staphyloccocus aureus clone that belongs to the ST121 complex and carries both epidermolysin (eta/etb) genes. We concluded that the SSSS caused by the newly emerged, highly virulent community-associated-methicillin sensitive S. aureus strains that have been encountered lately is more severe than impetigo. Physicians should be aware of the probability of SSSS epidemics from strains that are resistant to mupirocin and fusidic acid, which have been used irrationally and excessively. © 2019 The Authors.

A sharp increase in staphylococcal scalded skin syndrome (SSSS) cases has been recorded in our settings since 2015, with 31 cases having been documented during the period 2014–2017. The molecular investigation of strains from the above period showed the emergence of a methicillin-susceptible, mupirocin- and fusidic acid-resistant Staphyloccocus aureus clone that belongs to the ST121 complex and carries both epidermolysin (eta/etb) genes. We concluded that the SSSS caused by the newly emerged, highly virulent community-associated-methicillin sensitive S. aureus strains that have been encountered lately is more severe than impetigo. Physicians should be aware of the probability of SSSS epidemics from strains that are resistant to mupirocin and fusidic acid, which have been used irrationally and excessively.

Purpose. To investigate the clinical, phenotypic and genotypic characteristics of Staphylococcus aureus strains causing osteoarticular infections in a large paediatric series. Methodology. Medical records of children who were hospitalized with the diagnosis of community-associated S. aureus (CA-SA) osteomyelitis and/or septic arthritis in the two major tertiary paediatric hospitals of Athens during an 8-year period (2007–2015) were reviewed, and S. aureus isolates were analysed regarding antimicrobial resistance, detection of pathogenicity genes and genotyping using SCCmec, agr typing, PFGE and MLST. Results. During the study period, 123 children with CA-SA osteoarticular infections were identified, and methicillin-resistant S. aureus (MRSA) accounted for 44 of these (35.8 %). Children with MRSA infection had a significantly higher admission rate to the ICU (5.7 vs 0 %, P=0.04) and longer duration of hospitalization (21.6 vs 16.7 days, P=0.04). Sixty-eight isolates [42 (methicillin-sensitive S. aureus) MSSA and 26 MRSA] were available for molecular analysis. All MRSA strains were mecA-positive and most carried the SCCmec IV cassette (23/26, 88 %) and belonged to the PFGE type C (24/26, 92.3 %), agr type 3 (24/26, 92.3 %) and the MLST ST80 clone (24/26, 92.3 %). In contrast, MSSA strains showed polyclonality by PFGE and agr typing. Regarding pathogenicity genes, MRSA vs MSSA isolates showed higher detection rates of PVL (96.2 vs 4.8 %, P

OBJECTIVES: The objective of this study was to evaluate the ability of weighted-incidence syndromic combination antibiograms (WISCAs) to inform the selection of empirical antibiotic regimens for suspected paediatric bloodstream infections (BSIs) by comparing WISCAs derived using data from single hospitals and from a multicentre surveillance dataset. METHODS: WISCAs were developed by estimating the coverage of five empirical antibiotic regimens for childhood BSI using a Bayesian decision tree. The study used microbiological data on ∼2000 bloodstream isolates collected over 2 years from 19 European hospitals. We evaluated the ability of a WISCA to show differences in regimen coverage at two exemplar hospitals. For each, a WISCA was first calculated using only their local data; a second WISCA was calculated using pooled data from all 19 hospitals. RESULTS: The estimated coverage of the five regimens was 72%-86% for Hospital 1 and 79%-94% for Hospital 2, based on their own data. In both cases, the best regimens could not be definitively identified because the differences in coverage were not statistically significant. For Hospital 1, coverage estimates derived using pooled data gave sufficient precision to reveal clinically important differences among regimens, including high coverage provided by a narrow-spectrum antibiotic combination. For Hospital 2, the hospital and pooled data showed signs of heterogeneity and the use of pooled data was judged not to be appropriate. CONCLUSIONS: The Bayesian WISCA provides a useful approach to pooling information from different sources to guide empirical therapy and could increase confidence in the selection of narrow-spectrum regimens.

Purpose. To investigate the clinical, phenotypic and genotypic characteristics of Staphylococcus aureus strains causing osteoarticular infections in a large paediatric series. Methodology. Medical records of children who were hospitalized with the diagnosis of community-associated S. aureus (CASA) osteomyelitis and/or septic arthritis in the two major tertiary paediatric hospitals of Athens during an 8-year period (2007-2015) were reviewed, and S. aureus isolates were analysed regarding antimicrobial resistance, detection of pathogenicity genes and genotyping using SCCmec, agr typing, PFGE and MLST. Results. During the study period, 123 children with CA-SA osteoarticular infections were identified, and methicillin-resistant S. aureus (MRSA) accounted for 44 of these (35.8 %). Children with MRSA infection had a significantly higher admission rate to the ICU (5.7 vs 0 %, P=0.04) and longer duration of hospitalization (21.6 vs 16.7 days, P=0.04). Sixty-eight isolates [42 (methicillin-sensitive S. aureus) MSSA and 26 MRSA] were available for molecular analysis. All MRSA strains were mecApositive and most carried the SCCmec IV cassette (23/26, 88 %) and belonged to the PFGE type C (24/26, 92.3 %), agr type 3 (24/26, 92.3 %) and the MLST ST80 clone (24/26, 92.3 %). In contrast, MSSA strains showed polyclonality by PFGE and agr typing. Regarding pathogenicity genes, MRSA vs MSSA isolates showed higher detection rates of PVL (96.2 vs 4.8 %, P

Σκοπός: Ο Staphylococcus aureus (SA) είναι μείζον βακτηριακό παθογόνο, συχνά ανθεκτικό σε διάφορα αντιμικροβιακά και προκαλεί σημαντική νοσηρότητα αλλά και θνησιμότητα στην κοινότητα και το νοσοκομείο. Οι σταφυλοκοκκικές λοιμώξεις της κοινότητας από ανθεκτικό στη μεθικιλλίνη SA (community-associated methicillin resistant Staphylococcus aureus, CA-MRSA) είναι αρκετά συχνές στα παιδιά στην περιοχή μας. Σκοπός της παρούσας διατριβής είναι η επιδημιολογική, κλινική και μικροβιολογική διερεύνηση των σταφυλοκοκκικών λοιμώξεων της κοινότητας και η μοριακή μελέτη των στελεχών που απομονώθηκαν στο Νοσοκομείο Παίδων «Π. & Α. Κυριακού» κατά την δεκαετία 2007-2016. Αναλυτικά, μελετήθηκαν οι λοιμώξεις της κοινότητας από MRSA (CA-MRSA), οι λοιμώξεις από ανθεκτικό στη μουπιροκίνη - ευαίσθητο στη μεθικιλλίνη SA (2013-2016) και οι περιπτώσεις σταφυλοκοκκικής πνευμονίας της κοινότητας (2007-2014). Υλικό και Μέθοδοι: Καταγράφηκαν αναδρομικά μέχρι το 2012 και προοπτικά στη συνέχεια, όλες οι λοιμώξεις από S. aureus εξωνοσοκομειακών και νοσηλευόμενων ασθενών και κατηγοριοποιήθηκαν σε λοιμώξεις κοινότητας (community-associated, CA) και νοσοκομειακές (health care-associated, HA). H καταγραφή των ασθενών βασίσθηκε στα αρχεία του Μικροβιολογικού Εργαστηρίου του Νοσοκομείου Παίδων «Π. και Α. Κυριακού». Για τη μελέτη της πνευμονίας έγινε ανασκόπηση και των αρχείων του Μικροβιολογικού Εργαστηρίου του Νοσοκ. Παίδων «η Αγία Σοφία» καθώς και ανάλυση των αντιστοίχων στελεχών σταφυλοκόκκου. Οι καλλιέργειες των κλινικών δειγμάτων έγιναν σύμφωνα με τις μεθόδους του Μικροβιολογικού Εργαστηρίου, η ταυτοποίηση του μικροβίου με συμβατικές μεθόδους και ο έλεγχος ευαισθησίας στα αντιμικροβιακά φάρμακα έγινε σύμφωνα με τις οδηγίες του CLSI. Για αμφίβολα αποτελέσματα στην κεφοξιτίνη χρησιμοποιήθηκε το latex PBP2a Slidex MRSA Detection Kit (bioMerieux SA, France), και το D-test για τον προσδιορισμό του τύπου της αντοχής στην κλινδαμυκίνη. Στα διεισδυτικά στελέχη έγινε προσδιορισμός των MICs των αντιμικροβιακών βανκομυκίνη, τεϊκοπλανίνη και λινεζολίδη με ταινίες διαβαθμισμένης συγκέντρωσης. Μοριακή μελέτη με PCRs έγινε σε επιλεγμένα στελέχη για την ανίχνευση γονιδίων αντοχής στη μουπιροκίνη (mupA), το φουσιδικό οξύ (fusB) και την κλινδαμυκίνη (ermA, ermC), αλλά γονιδίων που κωδικοποιούν λοιμογόνους παράγοντες, όπως PVL (lukS/lukF-PV), επιδερμολυσίνες (eta, etb), fibronectin binding protein A (fnbA). Γονοτυπικές μέθοδοι (SCCmec και agr τυποποίηση), ηλεκτροφόρηση σε εναλλασσόμενο πεδίο (PFGE) και πολυτοπική ανάλυση αλληλουχιών (MLST) εφαρμόστηκαν για τον χαρακτηρισμό των κλώνων. Αποτελέσματα: Γενικά. Κατά το χρονικό διάστημα 2007-2016, καταγράφηκαν 5.423 περιστατικά σταφυλοκοκκικκών λοιμώξεων της κοινότητας (CA-SΑ). Η πλειονότητα των περιπτώσεων αφορούσε λοιμώξεις δέρματος και μαλακών μορίων (85.2%). Μεταξύ των 119 περιπτώσεων διεισδυτικής σταφυλοκοκκικής λοίμωξης, συχνότερες ήταν οι οι οστεοαρθρικές (ν=66, 55.5%) λοιμώξεις ακολουθούμενες από τις μικροβιαιμίες (25, 21%) και τις πνευμονίες (22, 18.5%). Ανθεκτικός στη μεθικιλλίνη σταφυλόκοκκος (MRSA) ήταν το αίτιο σε ποσοστό 41,2% του συνόλου των περιπτώσεων διεισδυτικής λοίμωξης και ήταν σημαντικά συχνότερος μεταξύ των περιπτώσεων πνευμονίας (86.4%, p50%), στην ερυθρομυκίνη 20% (9.45 – 34.9) και στην κλινδαμυκίνη 17.8% (8.7 – 33.3). Λοιμώξεις από ανθεκτικά στη μουπιροκίνη στελέχη σταφυλοκόκκου. Συνολικά, καταγράφηκαν 437 περιπτώσεις λοιμώξεων από ανθεκτικό στη μουπιροκίνη SA κατά την χρονική περίοδο 2013-2016. Όλα τα ως άνω στελέχη πλην τριών ήταν ευαίσθητα στη μεθικιλλίνη. Το μολυσματικό κηρίο ήταν η συχνότερη κλινική οντότητα (371, 84.9%), και δεύτερο σε συχνότητα το σταφυλοκοκκικό σύνδρομο δερματικής αποφολίδωσης (staphylococcal scalded skin syndrome, SSSS) (21, 4.8%), ενώ δεν διαπιστώθηκε περιστατικό αποστήματος οφειλόμενου στο στέλεχος αυτό. Οι λοιμώξεις από ανθεκτικό στη μουπιροκίνη SA παρουσίασαν αυξητική τάση κάθε έτος και ήταν συχνότερες κατά τους θερινούς μήνες. Αντοχή υψηλού επιπέδου στη μουπιροκίνη διαπιστώθηκε στο 99% και ιδιοσυστασιακή αντοχή στην κλινδαμυκίνη στο 20.1% των στελεχών. Μοριακή διερεύνηση διενεργήθηκε σε 102 αντιπροσωπευτικά στελέχη και εξ αυτών 100 (98%) ήταν mupA- και 97 (95%) fusB-θετικά, 83 (81.4%) lukS/lukF-θετικά, 95 (93%) eta/etb- θετικά συγχρόνως, και 99 (97%) fnbA-θετικά. 26/27 (96.3%) των ανθεκτικών στην κλινδαμυκίνη ήταν ermC-θετικά Γονοτυπικός έλεγχος των στελεχών με PFGE έδειξε ότι 96/99 (96.7%) στελέχη ανήκαν στον κύριο PFGE τύπο 1, ενώ ο έλεγχος με MLST σε τυχαία επιλεγμένα από κάθε τύπο στελεχη έδειξε ότι όλα ανήκαν στον ST121 κλώνο. Σταφυλοκοκκικές πνευμονίες. Κατά την περίοδο 2007-201 καταγράφηκαν 41 περιπτώσεις CA-SA πνευμονίας σε παιδιά (αγόρια 61%, διάμεσης ηλικίας 4.3 μηνών, IQR 2.8-28 μήνες) που νοσηλεύτηκαν στα δύο Παιδιατρικά Νοσοκομεία «Π. & Α. Κυριακού» και «Η Αγία Σοφία». MRSA απομονώθηκε σε 31 περιπτώσεις (75.6%). Οι συχνότερες επιπλοκές ήταν το εμπύημα (25/41, 61%), οι πνευματοκήλες (7/41, 17%) και το πνευμονικό απόστημα (1/41, 2.5%). Εισαγωγή στη Μονάδα Εντατικής Θεραπείας απαιτήθηκε σε 24 (58.5%) περιπτώσεις, ενώ δύο ασθενείς κατέληξαν (4.9%). Ως οριστική θεραπεία χορηγήθηκε βανκομυκίνη με ή χωρίς την προσθήκη άλλου αντιμικροβιακού (55.9%), κλινδαμυκίνη και λινεζολίδη (26.5% έκαστη). Όλα τα στελέχη ήταν ευαίσθητα στην βανκομυκίνη (MIC90 2mg/l, εύρος 1-2), τεϊκοπλανίνη (MIC90 1.5mg/l, εύρος 0.5-2) και λινεζολίδη (MIC90 1mg/l εύρος 0.25-2), ενώ 26.8% ήταν ανθεκτικά στην κλινδαμυκίνη. Μεταξύ των 25 μοριακά μελετηθέντων στελεχών, 20 ήταν mecA-θετικά και fnbA-θετικά. Από αυτά, 90% ανήκαν στον ST80-IV/agrIII/lukS/lukF-θετικό κλώνο. Τα MSSA στελέχη ήταν πολυκλωνικά, 3/5 ήταν lukS/lukF-θετικά και 3/5 fnbA-θετικά. Συμπεράσματα: Οι CA-MRSA λοιμώξεις μειώθηκαν στα παιδιά κατά την δεκαετία 2007-2016. Η συχνότητα της συνδυασμένης αντοχής στα αντιβιοτικά φουσιδικό οξύ, τετρακυκλίνη και καναμυκίνη που χρησιμοποιείται ως φαινοτυπικός δείκτης του Ευρωπαϊκού-ST-80-IV κλώνου μειώθηκε και αυτή. Οι λοιμώξεις δέρματος και μαλακών μορίων (Skin and soft tissue infections, SSTIs) επικρατούν συντριπτικά στις σταφυλοκοκοκκικές λοιμώξεις. Ωστόσο, από το 2013 και μετά αναδύθηκε ένας νέος κλώνος MSSA (ST121), που φέρει γονίδια αντοχής στα τοπικά αντιμικροβιακά φουσιδικό οξύ και μουπιροκίνη και παράγει επιδερμολυσίνες. O κλώνος αυτός ευθύνεται για την μεγάλη αύξηση κρουσμάτων μολυσματικού κηρίου. Η αντοχή στα πιο πάνω ευρέως χρησιμοποιούμενα αντιμικροβιακά διευκολύνει την μετάδοση του κλώνου αυτού στην κοινότητα. Επιπλέον, υπάρχει και αύξηση των περιπτώσεων SSSS συνεπεία του κλώνου αυτού. Οι παιδίατροι πρέπει να λάβουν το μήνυμα του περιορισμού της αλόγιστης χρήσης δερματικών αντιμικροβιακών σκευασμάτων στα παιδιά. Ο MRSA και ειδικά ο ST80-IV κλώνος επικράτησε ως αίτιο της CA-SA πνευμονίας στα παιδιά. Η χορηγούμενη αντιμικροβιακή ή/και χειρουργική θεραπεία ήταν αποτελεσματική σε όλες πλην δύο περιπτώσεων, παρόλη τη σχετικά υψηλή MIC στη βανκομυκίνη και το υψηλό ποσοστό αντοχής στην κλινδαμυκίνη. Objectives: Staphylococcus aureus (SA) is a well-established multidrug resistant pathogen, whereas community-acquired methicillin-resistant S. aureus (CA-MRSA) infections in children are of major concern. The purpose of this study was to assess the epidemiology, clinical characteristics, antimicrobial resistance patterns and molecular markers of certain S. aureus infections occurred in Greek children with no healthcare risk factors attending a large pediatric hospital in Athens during a ten-year period. CA-MRSA infections (2007-2016), skin and soft tissue infections (SSTIs) caused by mupirocin-resistant-methicillin-susceptible S. aureus strains (2013-2016) and CA-SA pneumonia cases (2007-2014) have been reviewed and studied. Methods: Cases and resistance patterns of all S. aureus isolates recovered from outpatients and inpatients were reviewed using the laboratory (LIS) and WHONET software. Medical files were reviewed where judged necessary and epidemiological categorization of infections as CA or HA was assigned. Cultures were performed according to the procedures of the microbiological laboratory. Identification of S. aureus was done by conventional methods (colony morphology, catalase test, latex agglutination test). Antimicrobial susceptibility testing was performed by disk diffusion method according the CLSI guidelines. For cefoxitin ambiguous results the latex PBP2a Slidex MRSA Detection Kit (bioMerieux SA, France) was used. A disk approximation test (D test) was used to detect inducible clindamycin resistance. Vancomycin, teicoplanin, linezolid MICs for invasive strains were determined by a gradient MIC method. Genes encoding high level (HLR) mupirocin resistance (mupA), fusidic acid resistance (fusB), ermA, ermC, PVL (lukS/lukF-PV), exfoliative toxins (eta, etb), fibronectin binding protein A (fnbA) were investigated in preserved selected strains by PCRs. Genotyping was performed by SCCmec and agr typing, whereas clonality was determined by PFGE and MLST. Results: During 2007-2016, 5423 CA-SA infections were recorded. Of these, 119 were invasive, osteoarticular infections were predominant (66, 55.5%), followed by bacteremia (25, 21%) and pneumonia (22, 18.5%). MRSA were 41.2% of invasive infections, strongly associated with pneumonia cases (86.4%, p50%), for erythromycin was 20% (9.45 – 34.9) and for clindamycin 17.8% (8.7 – 33.3). A total of 437 cases of mupirocin-resistant S. aureus were recorded for 2013-2016. All but 3 isolates were methicillin-susceptible. Impetigo was the predominant clinical entity (371, 84.9%) followed by staphylococcal skin scalded syndrome (21, 4.8%) wheras no abscesses were identified. The number of infections detected annually increased during the study years, especially during the summer months. The percentage of high-level-resistance to mupirocin and constitutive resistance to clindamycin were 99% and 20.1%, respectively. Among 102 representative strains available for molecular investigation, 100 (98%) were mupA- and 97 (95%) fusB-positive, 26/27 (96.3%) clindamycin-resistant strains were ermC-positive, 83 (81.4%) lukS/lukF-positive, 95 (93%) carried both eta/etb genes, 99 (97%) were fnbA-positive. Genotyping of MSSA strains revealed that 96/99 (96.7%) belonged to one main pulsotype 1 classified as ST121. During 2007-2014, 41 cases of CA-SA pneumonia were recorded (boys, 61%); median age 4.3 months from both pediatric hospitals “P. & A. Kyriakou” and “Aghia Sophia”. MRSA accounted for 31 cases (75.6%). Complications included empyema (25/41, 61%), pneumatoceles (7/41, 17%) and lung abscess (1/41, 2.5%). Intensive Care Unit admission was required in 58.5%. Two deaths occurred (4.9%). Definitive therapy was based on vancomycin with or without other antibiotics (55.9%), followed by clindamycin and linezolid (26.5% each). All isolates were susceptible to vancomycin (MIC90 2mg/l, range 1-2), teicoplanin (MIC90 1.5mg/l, range 0.5-2) and linezolid (MIC90 1mg/l range 0.25-2), whereas 26.8% were resistant to clindamycin. Among 25 studied strains, 20 were mecA-positive, carrying also the fnbA gene. Of these, 90% belonged to ST80-IV/agrIII/lukS/lukF - positive clone. MSSA strains showed polyclonality, 3/5 were lukS/lukF positive and 3/5 fnbA-positive. Conclusions: CA-MRSA infections have significantly declined among children over the last decade. Resistance to fusidic acid, kanamycin and tetracycline being a phenotypical marker of European ST80 is high among these strains but declines over time too. The spectrum of CA-MRSA infections in children in our area is largely associated with the spread of ST80 clone and their clinical characteristics are similar to those described in other parts of the world where different MRSA clones predominate.Moreover, a newly emerged MSSA clone (ST121) carrying genes for resistance to topical antimicrobials and epidermolysins, causing mainly impetigo was documented. Resistance and rich toxinogenic profile confers to this clone adaptability for spread in the community. SSSS cases were also on the rise due to the aforementioned clone. Pediatricians must be discouraged overprescribing topical antimicrobials in their practice. MRSA and particularly ST80-IV clone predominated among pediatric CA-SA pneumonia cases. Treatment provided was effective in all but two patients, despite relatively high MIC values of vancomycin and a high resistance rate to clindamycin.

The CMY-type enzymes are the most frequent acquired class C β-lactamases ([1][1]). Spread of the respective genes is mediated mostly by IncI and IncA/C plasmids ([2][2][–][3][4][4]). bla CMY-carrying ColE1 replicons have also been reported ([5][5]). Here, we describe a CMY-4-encoding IncQ plasmid

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.

Staphylococcus aureus is an infrequent cause of community-associated (CA-SA) pneumonia in children. The aim of this study was to evaluate the clinical, epidemiological, microbiological, and molecular characteristics of CA-SA pneumonia among children hospitalized in two large tertiary care referral centers during an 8-year period. Cases of CA-SA pneumonia admitted between 2007 and 2014 were retrospectively examined through medical record review. Molecular investigation was performed for available strains; mecA, Panton–Valentine leukocidin (PVL) (lukS-lukF-PV), and fibronectin binding protein A (fnbA) genes were detected by polymerase chain reaction (PCR). Clones were assigned by agr groups, pulsed-field gel electrophoresis (PFGE), SCCmec, and multilocus sequencing typing (MLST). In total, 41 cases were recorded (boys, 61 %), with a median age of 4.3 months (range, 1–175). Methicillin-resistant S. aureus (MRSA) accounted for 31 cases (75.6 %). Complications included empyema (25/41, 61 %), pneumatoceles (7/41, 17 %), and lung abscess (1/41, 2.5 %). Intensive care unit (ICU) admission was required in 58.5 %. Two deaths occurred (4.9 %). Definitive therapy was based on vancomycin with or without other antibiotics (55.9 %), followed by clindamycin and linezolid (26.5 % each). All isolates were susceptible to vancomycin (MIC90 2 mg/L, range 1–2), teicoplanin, and linezolid, whereas 26.8 % were resistant to clindamycin. Among the 25 studied strains, 20 were mecA-positive (MRSA), carrying also the fnbA gene. Of these, 90 % belonged to the ST80-IV/agr3/PVL-positive clone. Methicillin-susceptible S. aureus (MSSA) strains showed polyclonality, 3/5 were PVL-positive, and 3/5 were fnbA-positive. MRSA and particularly the ST80-IV clone predominated among staphylococcal pneumonia cases in children. Treatment provided was effective in all but two patients, despite the relatively high minimum inhibitory concentration (MIC) of vancomycin and a high resistance to clindamycin. © 2016, Springer-Verlag Berlin Heidelberg.

Objectives: The objective of this study was to evaluate the ability of weighted-incidence syndromic combination antibiograms (WISCAs) to inform the selection of empirical antibiotic regimens for suspected paediatric bloodstream infections (BSIs) by comparing WISCAs derived using data from single hospitals and from a multicentre surveillance dataset. Methods: WISCAs were developed by estimating the coverage of five empirical antibiotic regimens for childhood BSI using a Bayesian decision tree. The study used microbiological data on ~2000 bloodstream isolates collected over 2 years from 19 European hospitals. We evaluated the ability of a WISCA to show differences in regimen coverage at two exemplar hospitals. For each, a WISCA was first calculated using only their local data; a second WISCA was calculated using pooled data from all 19 hospitals. Results: The estimated coverage of the five regimens was 72%-86% for Hospital 1 and 79%-94% for Hospital 2, based on their own data. In both cases, the best regimens could not be definitively identified because the differences in coverage were not statistically significant. For Hospital 1, coverage estimates derived using pooled data gave sufficient precision to reveal clinically important differences among regimens, including high coverage provided by a narrow-spectrum antibiotic combination. For Hospital 2, the hospital and pooled data showed signs of heterogeneity and the use of pooled data was judged not to be appropriate. Conclusions: The Bayesian WISCA provides a useful approach to pooling information from different sources to guide empirical therapy and could increase confidence in the selection of narrow-spectrum regimens. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved.

The tendency of vancomycin, linezolid, and daptomycin MICs was investigated among 6920 staphylococci and enterococci during a 5-year period. Antimicrobial consumption was determined. Decrease of vancomycin MIC was detected associated with reduction in consumption. Linezolid and daptomycin remained active. An upward trend of linezolid MIC for methicillin-resistant staphylococci was observed.

Item does not contain fulltext BACKGROUND: Surveillance of antimicrobial resistance (AMR) is central for defining appropriate strategies to deal with changing AMR levels. It is unclear whether childhood AMR patterns differ from those detected in isolates from adult patients. METHODS: Resistance percentages of nonduplicate Staphylococcus aureus, Streptococcus pneumoniae, Enterococcus faecalis, Enterococcus faecium, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa bloodstream isolates from children less than 18 years of age reported to the Antibiotic Resistance and Prescribing in European Children (ARPEC) project were compared with all-age resistance percentages reported by the European Antimicrobial Resistance Surveillance Network (EARS-Net) for the same pathogen-antibiotic class combinations, period and countries. In addition, resistance percentages were compared between ARPEC isolates from children less than 1 year of age and children greater than or equal to1 year of age. RESULTS: Resistance percentages for many important pathogen-antibiotic class combinations were different for ARPEC isolates compared with EARS-Net. E. coli and K. pneumoniae fluoroquinolone resistance percentages were substantially lower in ARPEC (13.4% and 17.9%) than in EARS-Net (23.0% and 30.7%), whereas the reverse was true for all pathogen-antibiotic class combinations in P. aeruginosa (for example, 27.3% aminoglycoside resistance in ARPEC, 19.3% in EARS-Net, 32.8% carbapenem resistance in ARPEC and 20.5% in EARS-Net), and for S. pneumoniae and macrolide resistance. For many Gram-negative pathogen-antibiotic class combinations, isolates from children greater than or equal to 1 year of age showed higher resistance percentages than isolates from children less than 1 year of age. CONCLUSIONS: Age-stratified presentation of resistance percentage estimates by surveillance programs will allow identification of important variations in resistance patterns between different patient groups for targeted intervention. 01 juli 2015

Methicillin-resistant Staphylococcus aureus (MRSA) is an important cause of both healthcare-associated MRSA (HA-MRSA) and community-associated MRSA (CA-MRSA) infections. Severe MRSA infections have been associated with the virulence factor Panton–Valentine leukocidin (PVL). The aim of this study was to investigate susceptibility patterns, the presence of toxin genes, including that encoding PVL, and clonality among MRSA isolates collected from patients in Greece over a 12-year period. MRSA isolates were collected from January 2001 to December 2012 from six different hospitals. Antibiotic susceptibility was determined with the disk diffusion method and the Etest. The presence of the toxic shock syndrome toxin-1 gene ( tst ), the enterotoxin gene cluster ( egc ) and the PVL gene was tested with PCR. The genotypic characteristics of the strains were analysed by SCC mec and agr typing, and clonality was determined with pulsed-field gel electrophoresis and multilocus sequence typing. An increasing rate of MRSA among S. aureus infections was detected up to 2008. The majority of PVL-positive MRSA isolates belonged to a single clone, sequence type (ST)80-IV, which was disseminated both in the community and in hospitals, especially during the warmest months of the year. Carriage of tst was associated with ST30-IV, whereas egc was distributed in different clones. CA-MRSA isolates were recovered mainly from skin and soft tissue infections, whereas HA-MRSA isolates were associated with surgical and wound infections. During the period 2001–2012, ST80-IV predominated in the community and infiltrated the hospital settings in Greece, successfully replacing other PVL-positive clones. The predominance of ST239-III in HA-MRSA infections was constant, whereas new clones have also emerged. Polyclonality was statistically significantly higher among CA-MRSA isolates and isolates from adult patients.