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Purpose Severe community-acquired pneumonia (SCAP) is still associated with substantial morbidity and mortality. In this point-of-view review paper, a group of experts discuss the main controversies in SCAP: the role of severity scores to guide patient settings of care and empiric antibiotic therapy; the emergence of pathogens outside the core microorganisms of CAP; viral SCAP; the best empirical treatment; septic shock as the most lethal complication; and the need for new antibiotics. Methods For all topics, the authors describe current controversies and evidence and provide recommendations and suggestions for future research. Evidence was based on meta-analyses, most recent RCTs and recent interventional or observational studies. Recommendations were reached by consensus of all the authors. Results and conclusions The IDSA/ATS criteria remain the most pragmatic tool to predict ICU admission. The authors recommend a combination of a beta-lactam/beta-lactamase inhibitor or a third G cephalosporin plus a macrolide in most SCAP patients, and to empirically cover PES ( P. aeruginosa , extended spectrum beta-lactamase producing Enterobacteriaceae, methicillin-resistant S. aureus ) pathogens when at least two specific risk factors are present. In patients with influenza CAP, the authors recommend the use of oseltamivir and avoidance of the use of steroids. Corticosteroids can be used in case of refractory shock and high systemic inflammatory response.

Background. Recent worldwide reports of community-onset skin abscesses, outbreaks of furunculosis, and severe pneumonia associated with methicillin-resistant Staphylococcus aureus (MRSA) carrying Panton-Valentine leukocidin (PVL) genes and the staphylococcal cassette chromosome mec (SCCmec) type IV indicate that MRSA infections are evolving into a community-related problem. The majority of cases reported to date involve skin and soft-tissue infections, with severe pneumonia representing a relatively rare phenomenon. During a 2-month period in the winter of 2003–2004, four healthy adults presented to 1 of 2 Baltimore hospitals with severe necrotizing MRSA pneumonia in the absence of typical risk factors for MRSA infection. Methods. Patients' MRSA isolates were characterized by strain typing with use of pulsed-field gel electrophoresis and SCCmec typing with use of a multiplex polymerase chain reaction (PCR) assay and detection of PVL genes by PCR. Results. All 4 patients' MRSA isolates carried the PVL genes and the SCCmec type IV element and belonged to the USA300 pulsed-field type. These 3 findings are among the typical characteristics of community-onset MRSA strains. In addition, 2 of our patients had concomitant influenza A diagnosed, which likely contributed to the severity of their presentation. Conclusions. To our knowledge, these patients represent the first reported North American adults with severe community-onset MRSA pneumonia caused by strains carrying the PVL genes.

Amaç: Bu çalışmayla mikrobiyoloji laboratuvarına gönderilen çeşitli klinik örneklerden izole edilen metisiline dirençli Staphy- lococcus aureus (MRSA) suşlarında fusidik asidle birlikte diğer β-laktam dışı antibiyotiklerden linezolid, kinupristin/dalfo- pristin, kloramfenikol, rifampisin, levofloksasin ve siprofloksasin duyarlılığının araştırılması amaçlanmıştır. Yöntemler: Ocak 2011-Aralık 2014 arasında çeşitli klinik örneklerden izole edilen 84 MRSA suşu çalışmaya dahil edilmiştir. İzole edilen suşlar konvansiyonel yöntemlerle (Gram boyaması, katalaz ve koagülaz testleri) S. aureus olarak tanımlanmıştır. Suşların metisilin direnci, sefoksitin (10 μg) diski kullanılarak disk difüzyon yöntemiyle belirlenmiştir. European Committee on Antimicrobial Susceptibility Testing (EUCAST) Staphylococcus spp. için vankomisin zon çapı sınır değerleri içermediği için, suşların vankomisine duyarlılığının belirlenmesinde minimal inhibitör konsantrasyon (MİK) değerleri Etest® yöntemiyle araştırılmıştır. Suşların diğer β-laktam dışı antibiyotiklere in vitro duyarlılığını araştırmak için fusidik asid (10 μg), linezolid (10 μg), kinupristin/dalfopristin (15 μg), kloramfenikol (30 μg), rifampisin (5 μg), siprofloksasin (5 μg) ve levofloksasin (5 μg) diskleriyle Kirby-Bauer disk difüzyon yöntemi kullanılmıştır. Etest® yöntemiyle elde edilen vankomisin MİK değerleri ve Kirby-Bauer disk difüzyon yöntemiyle test edilen antibiyotiklerin zon çapları, EUCAST önerileri doğrultusunda yorumlanmıştır. Bulgular: 84 MRSA suşunun %56’sı yara, %32.1’i kan ve %11.9’u idrar örneklerinden izole edilen suşlardı. En fazla MRSA suşu izole edilen servisler sırasıyla Dahiliye (%17.9), Anestezi ve Reanimasyon Yoğun Bakım (%16.6), Beyin Cerrahisi (%14.3), Ortopedi ve Travmatoloji (%11.9) ve Pediyatri Servisi (%11.9) şeklinde idi. Vankomisin için elde edilen MİKmin-max, MİK50 ve MİK90 değerleri sırasıyla 0.75 µg/ml-1.5 µg/ml, 1 µg/ml ve 1.5 µg/ml olarak tespit edildi. Suşların tamamı vankomisin, linezolid ve kinupristin/dalfopristine duyarlı olarak saptandı. Antimikrobiyal duyarlılık oranları kloramfenikol için %96.4 ve fusidik asid için %76.2 olarak tespit edilmişken bu oran rifampisin, levofloksasin ve siprofloksasin için sırasıyla %20.2, %19 ve %16.6 olarak tespit edildi. Sonuçlar: MRSA infeksiyonlarının tedavisinde her ne kadar glikopeptidler ilk seçenek olarak kullanılmaktaysa da direnç gelişiminin önlenmesi amacıyla uygun indikasyonlarda fusidik asidin de antibiyotik duyarlılığı test edilerek tedavide alternatif olarak kullanılabileceği göz önünde bulundurulmalıdır. Klimik Dergisi 2019; 32(1): 52-6.

Amaç: Çalışmada günlük yaşantımızda, kullandığımız kırmızı, mavi, yeşil ve sarı renkte kumaş ve gıda boylarının farklı konsantrasyonlarının Metisilin Dirençli Staphylococcus aureus (MRSA) ve Pseudomonas aeruginosa standart suşlarının üremesi üzerine etkilerini belirlemek amaçlanmıştırYöntemler: Ticari olarak satılmakta olan yeşil, kırmızı, sarı ve mavi renklerde kumaş ve gıda boya maddelerinin steril serum fizyolojik içinde seri dilüsyonları yapıldı. Her bir konsantrasyon için 1ml olarak tüplere dağıtıldı. P. aeruginosa ve MRSA standart suşları üretildi. İki suşun ayrı ayrı 0,5 McFarland sulandırımları hazırlandı. Bu bakteri sulandırımlardan 100’er mikrolitre, dilüsyonları yapılan kumaş ve gıda boyalarının her bir dilüsyonuna eklendi. 37°C’de 18-24 saat inkübasyonu takiben her bir dilüsyondaki üremelerin tespiti için 1 mikrolitrelik steril tek kullanımlık özelerle Müeller Hinton agar besi yerine pasajları yapıldı. Bu besiyerleri 37°C de 18-24 saat inkübe edildikten sonra her bir alandaki koloniler sayıldı.Bulgular: Yeşil, sarı ve kırmızı renk gıda ve kumaş boyasının, MRSA'yı baskıladığı, P. aeruginosa’nın, MRSA’dan belirgin olarak fazla ürediği görüldü. Ancak mavi renkte hem kumaş hem gıda boyasının, her iki bakterinin de üremesini azalttığı koloni sayımları ile belirlendi.Sonuç: Bu çalışma sonucunda gıda ve kumaş boyalarını farklı konsantrasyonlarda, farklı renklerinin bakterilerin üremesi üzerine etkilerinin de değişken olduğu belirlendi.Ayrıca, bakterilerin kolayca bulaşabileceği ortamlarda kullanılan boya renklerinin bakteri kontaminasyonuna engel olunabileceğini gösteren in vitro sonuç da elde edildi.Anahtar kelimeler: Gıda boyası, kumaş boyası, metisilin dirençli Staphylococcus aureus, Pseudomonas aeruginosa Objective: The aim of this study to determine, the antibacterial effects of red, blue, green and yellow fabric and nutrient dyes, which were commonly used in our daily life on Methicillin Resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa with different concentration. Methods: Serial dilutions of commercially available green, red, yellow, and blue fabric and food dyes in sterile saline were prepared. One milliliter from each concentration of dyes was splitted into the tubes. McFarland 0.5 standard were used to adjust the turbidity of bacterial suspensions of P. aeruginosa and S. aureus standard strains. This suspension of each strain dispensed 100 microliters to all food and fabric dyes concentrations and incubated at 37°C. After overnight incubation 1 microliter suspension from each tube is plated on Mueller Hinton agar to determine bactericidal with sterile disposable loop. After incubation of these plates at 37°C for 18 - 24 hours, colonies were counted. Results: Green, yellow and red colors of fabric and food dyes were inhibited MRSA, and they showed significantly less effect against P. aeruginosa. However, blue fabric and food dye antibacterial affects, were greater than other colors against MRSA and also against P. aeruginosa.Conclusion: In this study, we determined that inhibition effect of food and fabric dyes, on bacterial growth can be variable belong to the color and concentration of dye. Our in vitro findings were indicated that colors of dyes can be a factor to inhibit bacterial contamination and true color choice will be helpful for painting especially high risk places for bacterial contamination. J Clin Exp Invest 2015; 6 (3): 274-278

Difficult-to-treat infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are of concern in people living with HIV infection as they are more vulnerable to infection. We aimed to identify molecular characteristics of MRSA colonizing newly diagnosed HIV-infected adults in Tanzania. Individuals newly diagnosed with HIV infection were recruited in Dar es Salaam, Tanzania, from April 2017 to May 2018, as part of the randomized clinical trial CoTrimResist (ClinicalTrials.gov identifier: NCT03087890). Nasal/nasopharyngeal isolates of Staphylococcus aureus were susceptibility tested by disk diffusion method, and cefoxitin-resistant isolates were characterized by short-reads whole genome sequencing. Four percent (22/537) of patients carried MRSA in the nose/nasopharynx. MRSA isolates were frequently resistant towards gentamicin (95%), ciprofloxacin (91%), and erythromycin (82%) but less often towards trimethoprim-sulfamethoxazole (9%). Seventy-three percent had inducible clindamycin resistance. Erythromycin-resistant isolates harbored ermC (15/18) and LmrS (3/18) resistance genes. Ciprofloxacin resistance was mediated by mutations of the quinolone resistance-determining region (QRDR) sequence in the gyrA (S84L) and parC (S80Y) genes. All isolates belonged to the CC8 and ST8-SCCmecIV MRSA clone. Ninety-five percent of the MRSA isolates were spa-type t1476, and one exhibited spa-type t064. All isolates were negative for Panton-Valentine leucocidin (PVL) and arginine catabolic mobile element (ACME) type 1. All ST8-SCCmecIV-spa-t1476 MRSA clones from Tanzania were unrelated to the globally successful USA300 clone. Carriage of ST8 MRSA (non-USA300) was common among newly diagnosed HIV-infected adults in Tanzania. Frequent co-resistance to non-beta lactam antibiotics limits therapeutic options when infection occurs.

Methicillin-Resistant Staphylococcus aureus (MRSA) is a significant threat to human health. Additionally, biofilm forming bacteria becomes more tolerant to antibiotics and act as bacterial reservoir leading to chronic infection. In this study, we characterised the antibiotic susceptibility, biofilm production and sequence types (ST) of 74 randomly selected clinical isolates of S. aureus causing ocular infections. Antibiotic susceptibility revealed 74% of the isolates as resistant against one or two antibiotics, followed by 16% multidrug-resistant isolates (MDR), and 10% sensitive. The isolates were characterized as MRSA (n = 15), Methicillin-sensitive S. aureus (MSSA, n = 48) and oxacillin susceptible mecA positive S. aureus (OS-MRSA, n = 11) based on oxacillin susceptibility, mecA gene PCR and PBP2a agglutination test. All OS-MRSA would have been misclassified as MSSA on the basis of susceptibility test. Therefore, both phenotypic and genotypic tests should be included to prevent strain misrepresentation. In addition, in-depth studies for understanding the emerging OS-MRSA phenotype is required. The role of fem XAB gene family has been earlier reported in OS-MRSA phenotype. Sequence analysis of the fem XAB genes revealed mutations in fem  × (K3R, H11N, N18H and I51V) and fem B (L410F) genes. The fem XAB genes were also found down-regulated in OS-MRSA isolates in comparison to MRSA. In OS-MRSA isolates, biofilm formation is regulated by fibronectin binding proteins A & B. Molecular typing of the isolates revealed genetic diversity. All the isolates produced biofilm, however, MRSA isolates with strong biofilm phenotype represent a worrisome situation and may even result in treatment failure.

This review assessed the molecular characterization of the methicillin-resistant Staphylococcus aureus (MRSA)-ST80 clone with an emphasis on its proportion of total MRSA strains isolated, PVL production, spa-typing, antibiotic resistance, and virulence. A systematic review of the literature was conducted on MRSA-ST80 clone published between 1 January 2000 and 31 August 2019. Citations were chosen for a review of the full text if we found evidence that MRSA-ST80 clone was reported in the study. For each isolate, the country of isolation, the sampling period, the source of isolation (the type of infection, nasal swabs, or extra-human), the total number of MRSA strains isolated, number of MRSA-ST80 strains, antibiotic resistance patterns, PVL production, virulence genes, and spa type were recorded. The data from 103 articles were abstracted into an Excel database. Analysis of the data showed that the overall proportion of MRSA-ST80 has been decreasing in many countries in recent years. The majority of MRSA-ST80 were PVL positive with spa-type t044. Only six reports of MRSA-ST80 in extra-human niches were found. This review summarizes the rise of MRSA-ST80 and the evidence that suggests that it could be in decline in many countries.

Staphylococcus aureus or methicillin-resistant Staphylococcus aureus (MRSA) is an important issue associated with significant morbidity and mortality and well known as a predominant pathogen causing bloodstream infection (BSIs) globally. To estimate the antibiotic resistance and molecular characteristics of S. aureus causing BSIs in Shanghai, 120  S. aureus isolates (20 isolates each year) from the patients with S. aureus BSIs from 2013 to 2018 were randomly selected and enrolled in this study. Fifty-three (44.2%) MRSA isolates were determined, and no isolate was found resistant to vancomycin, daptomycin, synercid, linezolid and ceftaroline. The toxin genes tst , sec , seg and sei were found more frequently among MRSA isolates compared with MSSA isolates (all P  < 0.0001). Twenty-nine sequence types (STs) were identified, and ST5 (23.3%) was the most common ST, followed by ST398 (11.7%) and ST764 (10.0%). SCC mec II (73.6%) was the most frequent SCC mec type among MRSA isolates. The dominant clonal complexes (CCs) were CC5 (ST5, ST764, ST965 and ST3066; 36.7%) and the livestock-associated clone CC398 (ST398, 11.7%). MRSA-CC5 was the predominant CC among MRSA isolates (37/53, 69.8%), and CC5-II MRSA was found in 34 isolates accounting for 91.9% (34/37) among CC5 MRSA isolates. In addition, all 29 tst -positive MRSA isolates were CC5-MRSA as well. Our study provided the properties and genotypes of S. aureus causing BSIs at Ruijin Hospital in Shanghai from 2013 to 2018, and might suggest of value clues for the further study insights into pathogenic mechanisms intrinsically referring to the development of human-adapted S. aureus clones and their diffusions.

Background: The incidence of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections is increasing in the United States, and it is possible that municipal wastewater could be a reservoir of this microorganism. To date, no U.S. studies have evaluated the occurrence of MRSA in wastewater. Objective: We examined the occurrence of MRSA and methicillin-susceptible S. aureus (MSSA) at U.S. wastewater treatment plants. Methods: We collected wastewater samples from two Mid-Atlantic and two Midwest wastewater treatment plants between October 2009 and October 2010. Samples were analyzed for MRSA and MSSA using membrane filtration. Isolates were confirmed using biochemical tests and PCR (polymerase chain reaction). Antimicrobial susceptibility testing was performed by Sensititre® microbroth dilution. Staphylococcal cassette chromosome mec (SCCmec) typing, Panton-Valentine leucocidin (PVL) screening, and pulsed field gel electrophoresis (PFGE) were performed to further characterize the strains. Data were analyzed by two-sample proportion tests and analysis of variance. Results: We detected MRSA (n = 240) and MSSA (n = 119) in 22 of 44 (50%) and 24 of 44 (55%) wastewater samples, respectively. The odds of samples being MRSA-positive decreased as treatment progressed: 10 of 12 (83%) influent samples were MRSA-positive, while only one of 12 (8%) effluent samples was MRSA-positive. Ninety-three percent and 29% of unique MRSA and MSSA isolates, respectively, were multidrug resistant. SCCmec types II and IV, the pvl gene, and USA types 100, 300, and 700 (PFGE strain types commonly found in the United States) were identified among the MRSA isolates. Conclusions: Our findings raise potential public health concerns for wastewater treatment plant workers and individuals exposed to reclaimed wastewater. Because of increasing use of reclaimed wastewater, further study is needed to evaluate the risk of exposure to antibiotic-resistant bacteria in treated wastewater.