Prevalence of methicillin-resistant Staphylococcus aureus and ...

African Journals Online (AJOL)

Wound colonization by microorganisms is most frequently polymicrobial and incidences of high level resistance among bacterial isolates from wounds have been reported. Methicillin-resistant Staphylococcus aureus (MRSA) and extendedspectrum beta-lactamase (ESBL) producing Gram-negative bacteria both constitute ...

Methicillin-resistant Staphylococcus aureus isolates from Iranian ...

African Journals Online (AJOL)

Methicillin-resistant Staphylococcus aureus isolates from Iranian restaurant food samples: Panton-Valentine Leukocidin, SCCmec phenotypes and antimicrobial resistance. ... TetK (80.72 %), linA (67.46 %), aadA1 (62.65 %), and msrA (55.42 %) were the most frequently identified resistance genes. SCCmec V (57.83%) ...

Molecular mechanisms of methicillin resistance in Staphylococcus aureus.

Science.gov (United States)

Domínguez, M A; Liñares, J; Martín, R

1997-09-01

Methicillin-resistant Staphylococcus aureus (MRSA) strains are among the most common nosocomial pathogens. The most significant mechanism of resistance to methicillin in this-species is the acquisition of a genetic determinant (mecA gene). However, resistance seems to have a more complex molecular basis, since additional chromosomal material is involved in such resistance. Besides, overproduction of penicillinase and/or alterations in the PBPs can contribute to the formation of resistance phenotypes. Genetic and environmental factors leading to MRSA are reviewed.

Oxacillin sensitization of methicillin-resistant Staphylococcus aureus and methicillin-resistant Staphylococcus pseudintermedius by antisense peptide nucleic acids in vitro.

Science.gov (United States)

Goh, Shan; Loeffler, Anette; Lloyd, David H; Nair, Sean P; Good, Liam

2015-11-11

Antibiotic resistance genes can be targeted by antisense agents, which can reduce their expression and thus restore cellular susceptibility to existing antibiotics. Antisense inhibitors can be gene and pathogen specific, or designed to inhibit a group of bacteria having conserved sequences within resistance genes. Here, we aimed to develop antisense peptide nucleic acids (PNAs) that could be used to effectively restore susceptibility to β-lactams in methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus pseudintermedius (MRSP). Antisense PNAs specific for conserved regions of the mobilisable gene mecA, and the growth essential gene, ftsZ, were designed. Clinical MRSA and MRSP strains of high oxacillin resistance were treated with PNAs and assayed for reduction in colony forming units on oxacillin plates, reduction in target gene mRNA levels, and cell size. Anti-mecA PNA at 7.5 and 2.5 μM reduced mecA mRNA in MRSA and MRSP (p resistance in staphylococci. Further studies are warranted as clinical treatment alternatives are needed.

Methicillin-resistant Staphylococcus sp. colonizing health care workers of a cancer hospital

Science.gov (United States)

Costa, Dayane de Melo; Kipnis, André; Leão-Vasconcelos, Lara Stefânia Netto de Oliveira; Rocha-Vilefort, Larissa Oliveira; Telles, Sheila Araújo; André, Maria Cláudia Dantas Porfírio Borges; Tipple, Anaclara Ferreira Veiga; Lima, Ana Beatriz Mori; Ribeiro, Nádia Ferreira Gonçalves; Pereira, Mayara Regina; Prado-Palos, Marinésia Aparecida

2014-01-01

The aim of the study was to analyze epidemiological and microbiological aspects of oral colonization by methicillin-resistant Staphylococcus of health care workers in a cancer hospital. Interview and saliva sampling were performed with 149 health care workers. Antimicrobial resistance was determined by disk diffusion and minimum inhibitory concentration. Polymerase Chain Reaction, Internal Transcribed Spacer-Polymerase Chain Reaction and Pulsed Field Gel Electrophoresis were performed for genotypic characterization of methicillin-resistant Staphylococcus. Risk factors were determined by logistic regression. Methicillin-resistant Staphylococcus colonization prevalence was 19.5%, denture wearing (p = 0.03), habit of nail biting (p = 0.04) and preparation and administration of antimicrobial (p = 0.04) were risk factors identified. All methicillin-resistant Staphylococcus were S. epidermidis, 94.4% of them had mecA gene. Closely related and indistinguishable methicillin-resistant S. epidermidis were detected. These results highlight that HCWs which have contact with patient at high risk for developing infections were identified as colonized by MRSE in the oral cavity, reinforcing this cavity as a reservoir of these bacteria and the risk to themselves and patients safety, because these microorganisms may be spread by coughing and talking. PMID:25477910

Survey of Staphylococcus isolates among hospital personnel, environment and their antibiogram with special emphasis on methicillin resistance

Directory of Open Access Journals (Sweden)

Shobha K

2005-01-01

Full Text Available The objective of this study was to find the prevalence of Staphylococcus spp. carriage among hospital personnel and hospital environment and their antibiogram with special emphasis on methicillin resistance. A total of 205 samples from hospital personnel and environment were collected from casualty, oncology and multidisciplinary cardiac unit ward of Kasturba Medical College Hospital, Manipal. Samples were collected using sterile cotton wool swabs and inoculated into brain heart infusion broth. Subcultures were done onto blood agar and MacConkey′s agar. Isolates were identified by standard methods up to species level. Antimicrobial susceptibility test was performed according to standardized disc diffusion Kirby-Bauer method. Each of the isolates was screened for methicillin resistance using oxacillin disc on Mueller Hinton agar plate followed by MIC for methicillin and cefoxitin susceptibility test by disc diffusion method. Sixty five out of 205 strains (31.7% were Staphylococcus spp. and all of them were coagulase negative. Most of the strains belonged to S.epidermidis 49.23%(32/65 followed by S. saprophyticus 26.15%(17/65. Maximum isolates of S.epidermidis were from anterior nares 28.12%(9/32 strains of S.epidermidis . Highest number of methicillin resistant coagulase negative strains (3/9, 33.33% were isolated from stethoscope of multidisciplinary cardiac unit ward followed by carriers in the anterior nares (2/9, 22.22%. Methicillin resistant coagulase negative staphylococci are prevalent in anterior nares of hospital personnel and in the hospital environment thereby providing a definite source for hospital acquired infection. All isolates were sensitive to vancomycin, ciprofloxacin and amikacin.

Antibiotic susceptibility pattern of staphylococcus aureus and methicillin-resistant staphylococcus aureus in a tertiary care hospital

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CP Bhatt

2014-04-01

Full Text Available Background: Methicillin resistant Staphylococcus aureushas emerged as one of the most important nosocomial pathogens. It invokes a tremendous financial burden and enhanced morbidity and mortality due to difficult to treat systemic infections.Aim of this study was to determine antibiotic susceptibility pattern of Staphylococcus aureus and Methicillin resistant Staphylococcus aureus. Materials and Methods: Different clinical specimens were collected and processed for routine culture and antibiotic sensitivity test by standard microbiology techniques. Results: Out of 1173 samples received for microbiological examination, 100 were found to be S. aureus with 19% cases were Methicillin resistant Staphylococcus aureus (MRSA. Fourteen MRSA were found from inpatient and 5 were from outpatient. MRSA was found higher in female than male and maximum number (31.5% was found in age group 0-10 years. Staphylococcus aureus was 100% sensitive to Vancomycin followed by Amikacin (90%, Gentamycin (83%, and tetracycline (81%. On urine isolates Nitrofurantoin(91.6% was drug of choice. All the isolates were resistant to Penicillin G. In case of Methicillin resistant Staphylococcus aureus showed 100% sensitive to Vancomycin followed by Amikacin (84.2%, Tetracycline (63.1%, Ciprofloxacin (42% and Gentamycin (36.8%. Among urine isolates Nitrofutantoin showed 87.5% sensitive followed by Norfloxacin (75%. Conclusion: Methicillin resistant Staphylococcus aureus was found 19% of Staphylococcus aureus isolates. It was most common in females, hospitalized patients and young age group. Vancomycin seems to be drug of choice followed by Amikacin. It would be helpful to formulating and monitoring the antibiotic policy and ensure proper empiric treatment. DOI: http://dx.doi.org/10.3126/jpn.v4i7.10297 Journal of Pathology of Nepal (2014 Vol. 4, 548-551   

A Research of nasal methicillin resistant/sensitive Staphylococcus ...

African Journals Online (AJOL)

A Research of nasal methicillin resistant/sensitive Staphylococcus aureus and pharyngeal beta-haemolytic Streptococcus carriage in midwifery students in Kahramanmaras, Eastern Mediterranean Region of Turkey.

Prevalence and risk factors for methicillin resistant Staphylococcus ...

African Journals Online (AJOL)

Prevalence and risk factors for methicillin resistant Staphylococcus aureus carriage among emergency department workers and bacterial contamination on touch surfaces in Erciyes University Hospital, Kayseri, Turkey.

Molecular epidemiology of Staphylococcus spp. contamination in the ward environment: study on mecA and femA genes in methicillin-resistant strains.

Science.gov (United States)

Ashimoto, A; Hamada, T; Adachi, A; Tanigawa, T; Tanaka, Y

1995-01-01

Staphylococcus spp. were isolated from the ward environment and antibiotic susceptibility tests were performed. Twenty-nine strains out of 274 isolates were S. aureus, and 41.4% of the S. aureus strains were methicillin resistant (MRSA). All 12 strains of MRSA were also resistant to oxacillin, ceftizoxime, ampicillin and clindamycin. Among the coagulase-negative staphylococci (CNS), methicillin-resistant (MR) strains of S. epidermidis, S. capitis, S. warneri, S. haemolyticus, S. hominis, S. auricularis, S. saprophyticus and S. cohnii were isolated. Eight of the 10 S. Haemolyticus strains were methicillin resistant. The femA gene was detected in S. aureus (MSSA and MRSA), but not in CNS by polymerase chain reaction (PCR) analysis and Southern blot analysis. The mecA gene was found in all the MRSA and MR-S. epidermidis strains tested, and one of the two MR-S. hominis strains, but not in MSSA, MS-S. epidermidis, MS-S. hominis, or MS-S. haemolyticus. DNA from one strain of MR-S. hominis and 2 strains of MR-S. haemolyticus was not amplified by PCR using the mecA gene primer, or hybridized by Southern blotting. The ambiguity that mecA was detected in some MR-CNS strains, but not in others is discussed.

Isolation and Identification of Methicillin-resistant Staphylococcus ...

African Journals Online (AJOL)

cHyE sHaN

2012-06-21

Jun 21, 2012 ... Accepted 23 March, 2012. Methicillin-resistant Staphylococcus aureus (MRSA) is a nosocomial pathogen of increasing risk on community. ... become more prevalent as nosocomial pathogens causing severe infections ... prevention of transmission among hospitalized patients. Unrecognized MRSA carriers ...

In vitro phagocytosis of methicillin resistant and methicillin sensitive staphylococcus aureus by human polymorphonuclear leucocytes

International Nuclear Information System (INIS)

Javed, N.; Tahir, R.; Abbas, A.

2009-01-01

Staphylococcus aureus is a gram positive bacterium that causes a number of diseases such as abscesses, infective endocarditis, septic arthritis, etc. It is acquiring resistance against many antibiotics like methicillin; therefore its control is becoming increasingly difficult. Peripheral blood phagocytes particularly polymorphonuclear leucocytes play an important role in the protective mechanisms against these organisms. Phagocytes interact with bacteria and phagocytose these microorganisms to kill them. Phenotypically different isolates of Staphylococcus aureus including methicillin resistant Staphylococcus aureus (MRSA) and methicillin sensitive Staphylococcus aureus (MSSA) were collected from various hospitals of Lahore, Pakistan. Fresh polymorphonuclaer leucocytes were obtained from healthy individuals by centrifugation using Ficol-Hypaque gradient combined with dextran sedimentation. Microbiological method was used for the determination of phagocytic index of phenotypic variants of Staphylococcus aureus. A significant difference was observed between the phagocytic index of both bacterial groups. MSSA group showed the Mean+-SD of 79.46%+-3.9 while MRSA group showed 72.35%+-2.5. Significant difference in phagocytic index indicates that it can be one of the mechanisms of MRSA to evade host immune system as compare to MSSA. (author)

Methicillin-resistant Staphylococcus aureus prevention strategies in the ICU: a clinical decision analysis*.

Science.gov (United States)

Ziakas, Panayiotis D; Zacharioudakis, Ioannis M; Zervou, Fainareti N; Mylonakis, Eleftherios

2015-02-01

ICUs are a major reservoir of methicillin-resistant Staphylococcus aureus. Our aim was to estimate costs and effectiveness of methicillin-resistant Staphylococcus aureus prevention policies. We evaluated three up-to-date methicillin-resistant Staphylococcus aureus prevention policies, namely, 1) nasal screening and contact precautions of methicillin-resistant Staphylococcus aureus-positive patients; 2) nasal screening, contact precautions, and decolonization (targeted decolonization) of methicillin-resistant Staphylococcus aureus carriers; and 3) universal decolonization without screening. We implemented a decision-analytic model with deterministic and probabilistic analyses. Methicillin-resistant Staphylococcus aureus infections averted, quality-adjusted life years gained, and incremental cost-effectiveness ratios were calculated. Cost-effectiveness planes and acceptability curves were plotted for various willingness-to-pay thresholds to address uncertainty. At base-case scenario, universal decolonization was the dominant strategy; it averted 1.31% and 1.59% of methicillin-resistant Staphylococcus aureus infections over targeted decolonization and screening and contact precautions, respectively, and saved $16,203/quality-adjusted life year over targeted decolonization and 14,562/quality-adjusted life year over screening and contact precautions. Results were robust in sensitivity analysis for a wide range of input variables. In probabilistic analysis, universal decolonization increased quality-adjusted life years by 1.06% (95% CI, 1.02-1.09) over targeted decolonization and by 1.29% (95% CI, 1.24-1.33) over screening and contact precautions; universal decolonization resulted in average savings of $172 (95% CI, $168-$175) and $189 (95% CI, $185-$193) over targeted decolonization and screening and contact precautions, respectively. With willingness-to-pay threshold per quality-adjusted life year gained ranging from $0 to $50,000, universal decolonization was dominant

Carriage of methicillin-resistant Staphylococcus pseudintermedius in small animal veterinarians

DEFF Research Database (Denmark)

Paul, Narayan Chandra; Moodley, Arshnee; Ghibaudo, G.

2011-01-01

Methicillin-resistant Staphylococcus pseudintermedius (MRSP) is increasingly reported in small animals and cases of human infections have already been described despite its recent emergence in veterinary practice. We investigated the prevalence of MRSP and methicillin-resistant Staphylococcus...... aureus (MRSA) among small animal dermatologists attending a national veterinary conference in Italy. Nasal swabs were obtained from 128 veterinarians, seven of which harboured MRSP (n = 5; 3.9%) or MRSA (n = 2; 1.6%). A follow-up study of two carriers revealed that MRSP persisted for at least 1 month...... by spa typing. Methicillin-resistant isolates were further typed by antimicrobial susceptibility testing, SCCmec and multi-locus sequence typing. Two lineages previously associated with pets were identified among the five MRSP isolates; the European epidemic clone ST71-SCCmec II-III and ST106-SCCmec IV...

Prevalence of Methicillin and Vancomycin resistant Staphylococcus aureus colonization in nasopharynx; Amir-Alam hospital, 2005

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Hasibi M

2007-07-01

Full Text Available Background: Staphylococcus aureus is one of the most common causes of nosocomial infections with high morbidity and mortality rate. Traditionally, methicillin resistant staphylococcus aureus has been considered a major nosocomial pathogen in healthcare facilities, but in the past decade, it has been observed emerging in the community as well. Informations regarding hospital microbial colonization could be an important step for prevention of nosocomial infections. Our objective was clarifying the prevalence of methicillin resistant and vancomycin resistant staphylococcus aureus colonization in nasopharynx. Methods: A descriptive cross sectional study was carried on 106 patients and nursing staff of surgery and hemodialysis wards in Amir-Alam hospital from April 2005 to July 2005. The samples were collected from nasal region of cases using cotton swab by two experienced technician and were sent to laboratory for culture and antibiogram. Results: Twenty six (29.5% out of 106 cases were nasopharyngeal carriers of staphylococcus aureus. Eight cases (7.5% had methicillin resistant staphylococcus aureus. The most frequent colonization rate was seen in hemodialysis nursing staff and in all of them methicillin resistant staphylococcus aureus was reported. Carrier rates in hemodialysis patients were twice compared to surgery ward patients. The interesting point was that no sample of vancomycin resistant staphylococcus aureus was isolated. Conclusion: Prevalence of methicillin resistant staphylococcus aureus colonization seems to be increased; therefore proper management for controlling this problem is mandatory. The results of the present study suggest that the prevalence of methicillin resistant staphylococcus aureus infections is higher than was expected in Iran and vigorous preventive strategies should therefore be taken to stop the growth of this major health problem.

Subinhibitory concentrations of imipenem induce increased resistance to methicillin and imipenem in vitro in methicillin-resistant Staphylococcus aureus.

OpenAIRE

Forbes, B A; McClatchey, K D; Schaberg, D R

1984-01-01

Methicillin-resistant (MR) Staphylococcus aureus that was susceptible to less than 0.75 micrograms of imipenem per ml demonstrated inducible resistance. MR S. aureus preincubated with 0.05 microgram of imipenem per ml grew in medium with an imipenem concentration of 32 micrograms/ml, and methicillin MICs increased 20-fold. Non-MR S. aureus exhibited no induction. Preincubation with methicillin produced no effect. Induction appeared to be a unique interaction of imipenem with MR S. aureus.

Characterization of staphylococci in urban wastewater treatment plants in Spain, with detection of methicillin resistant Staphylococcus aureus ST398.

Science.gov (United States)

Gómez, Paula; Lozano, Carmen; Benito, Daniel; Estepa, Vanesa; Tenorio, Carmen; Zarazaga, Myriam; Torres, Carmen

2016-05-01

The objective of this study was to determine the prevalence of Staphylococcus in urban wastewater treatment plants (UWTP) of La Rioja (Spain), and to characterize de obtained isolates. 16 wastewater samples (8 influent, 8 effluent) of six UWTPs were seeded on mannitol-salt-agar and oxacillin-resistance-screening-agar-base for staphylococci and methicillin-resistant Staphylococcus aureus recovery. Antimicrobial susceptibility profile was determined for 16 antibiotics and the presence of 35 antimicrobial resistance genes and 14 virulence genes by PCR. S. aureus was typed by spa, agr, and multilocus-sequence-typing, and the presence of immune-evasion-genes cluster was analyzed. Staphylococcus spp. were detected in 13 of 16 tested wastewater samples (81%), although the number of CFU/mL decreased after treatment. 40 staphylococci were recovered (1-5/sample), and 8 of them were identified as S. aureus being typed as (number of strains): spa-t011/agr-II/ST398 (1), spa-t002/agr-II/ST5 (2), spa-t3262/agr-II/ST5 (1), spa-t605/agr-II/ST126 (3), and spa-t878/agr-III/ST2849 (1). S. aureus ST398 strain was methicillin-resistant and showed a multidrug resistance phenotype. Virulence genes tst, etd, sea, sec, seg, sei, sem, sen, seo, and seu, were detected among S. aureus and only ST5 strains showed genes of immune evasion cluster. Thirty-two coagulase-negative Staphylococcus of 12 different species were recovered (number of strains): Staphylococcus equorum (7), Staphylococcus vitulinus (4), Staphylococcus lentus (4), Staphylococcus sciuri (4), Staphylococcus fleurettii (2), Staphylococcus haemolyticus (2), Staphylococcus hominis (2), Staphylococcus saprophyticus (2), Staphylococcus succinus (2), Staphylococcus capitis (1), Staphylococcus cohnii (1), and Staphylococcus epidermidis (1). Five presented a multidrug resistance phenotype. The following resistance and virulence genes were found: mecA, lnu(A), vga(A), tet(K), erm(C), msr(A)/(B), mph(C), tst, and sem. We found that

Prevalence and Pattern of Methicillin Resistant Staphylococcus ...

African Journals Online (AJOL)

This trend is on the increase consequently there is prolong hospital stay, increased hospital bills, and increased morbidity and mortality. The widespread use of antimicrobial agents such as the â- lactam antibiotics has contributed to the emergence of Methicillin Resistant Staphylococcus aureus(MRSA); which has become ...

Staphylococcus aureus: methicillin-susceptible S. aureus to methicillin-resistant S. aureus and vancomycin-resistant S. aureus.

Science.gov (United States)

Rehm, Susan J; Tice, Alan

2010-09-15

The evolution of methicillin-resistant and vancomycin-resistant Staphylococcus aureus has demanded serious review of antimicrobial use and development of new agents and revised approaches to prevent and overcome drug resistance. Depending on local conditions and patient risk factors, empirical therapy of suspected S. aureus infection may require coverage of drug-resistant organisms with newer agents and novel antibiotic combinations. The question of treatment with inappropriate antibiotics raises grave concerns with regard to methicillin-resistant S. aureus selection, overgrowth, and increased virulence. Several strategies to reduce the nosocomial burden of resistance are suggested, including shortened hospital stays and outpatient parenteral antimicrobial therapy of the most serious infections.

Prevalence of methicillin-resistant Staphylococcus aureus (MRSA ...

African Journals Online (AJOL)

One of each duplicate swab sample was inoculated directly onto chocolate agar, incubated for 24 hours at 37oc while the other swab was used to make a smear for Gram staining. All isolates were identified using standard microbiological methods. Staphylococcus aureus isolates were screened for methicillin resistance ...

Nasal Carriage Rate of Methicillin Resistant Staphylococcus aureus among Health Care Workers at a Tertiary Care Hospital in Kathmandu, Nepal.

Science.gov (United States)

Khatri, S; Pant, N D; Bhandari, R; Shrestha, K L; Shrestha, C D; Adhikari, N; Poudel, A

2017-01-01

Methicillin-resistant Staphylococcus aureus is one of the most common causes of nosocomial infections. Due to its multidrug resistant nature; infections due to Methicillin-resistant Staphylococcus aureus are often very difficult to treat. Colonized health care workers are the important sources of Methicillin-resistant Staphylococcus aureus. The objectives of this study were to determine the nasal carriage rate of Methicillin-resistant Staphylococcus aureus among health care workers at Kathmandu Medical College and Teaching Hospital, Nepal and to assess their antimicrobial susceptibility patterns. A cross sectional study was conducted among 252 health care workers from July to November 2013. Mannitol salt agar was used to culture the nasal swabs. Antimicrobial susceptibility testing was performed by Kirby-Bauer disc diffusion technique following Clinical and Laboratory Standards Institute guidelines. Methicillin-resistant Staphylococcus aureus strains were confirmed by using cefoxitin disc and by determining the minimum inhibitory concentration of oxacillin by agar dilution method. Of 252 healthcare workers, 46(18.3%) were positive for Staphylococcus aureus among which 19(41.3%) were Methicillin-resistant Staphylococcus aureus carriers. Overall rate of nasal carriage of Methicillin-resistant Staphylococcus aureus was 7.5% (19/252).The higher percentages of lab personnel were nasal carriers of S. aureus (31.6%) and Methicillin-resistant Staphylococcus aureus (10.5%).The percentages of nasal carriage of S. aureus (35.7%) and Methicillin-resistant Staphylococcus aureus (14.3%) were highest in the health care workers from post operative department. Higher percentage of Methicillin-resistant Staphylococcus aureus were susceptible toward amikacin (100%) and vancomycin (100%) followed by cotrimoxazole (84.2%). High rates of nasal carriage of S. aureus and Methicillin-resistant Staphylococcus aureus were observed among the healthcare workers, which indicate the need of

Short communication: Prevalence of methicillin resistance in coagulase-negative staphylococci and Staphylococcus aureus isolated from bulk milk on organic and conventional dairy farms in the United States.

Science.gov (United States)

Cicconi-Hogan, K M; Belomestnykh, N; Gamroth, M; Ruegg, P L; Tikofsky, L; Schukken, Y H

2014-05-01

The objective of this study was to evaluate the presence of methicillin-resistant Staphylococcus aureus and coagulase-negative Staphylococcus spp. in bulk tank milk samples from 288 organic and conventional dairy farms located in New York, Wisconsin, and Oregon from March 2009 to May 2011. Due to recent publications reporting the presence mecC (a mecA homolog not detected by traditional mecA-based PCR methods), a combination of genotypic and phenotypic approaches was used to enhance the recovery of methicillin-resistant organisms from bulk tank milk. In total, 13 isolates were identified as methicillin resistant: Staph. aureus (n=1), Staphylococcus sciuri (n=5), Staphylococcus chromogenes (n=2), Staphylococcus saprophyticus (n=3), Staphylococcus agnetis (n=1), and Macrococcus caseolyticus (n=1). The single methicillin-resistant Staph. aureus isolate was identified from an organic farm in New York, for an observed 0.3% prevalence at the farm level. The methicillin-resistant coagulase-negative staphylococci prevalence was 2% in the organic population and 5% in the conventional population. We did not identify mecC in any of the isolates from our population. Of interest was the relatively high number of methicillin-resistant Staph. sciuri recovered, as the number of isolates from our study was considerably higher than those recovered from other recent studies that also assessed milk samples. Our research suggests that the presence of a potential methicillin-resistant Staphylococcus reservoir in milk, and likely the dairy farm population in the United States, is independent of the organic or conventional production system. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Evaluation of the synergistic potential of vancomycin combined with other antimicrobial agents against methicillin-resistant Staphylococcus aureus and coagulase-negative Staphylococcus spp strains

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Lívia Viganor da Silva

2011-02-01

Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA and coagulase-negative Staphylococcus spp (CNS are the most common pathogens that cause serious long term infections in patients. Despite the existence of new antimicrobial agents, such as linezolid, vancomycin (VAN remains the standard therapy for the treatment of infections caused by these multidrug-resistant strains. However, the use of VAN has been associated with a high frequency of therapeutic failures in some clinical scenarios, mainly with decreasing concentration of VAN. This work aims to evaluate the synergic potential of VAN plus sulfamethoxazole/trimethoprim (SXT, VAN plus rifampin (RIF and VAN plus imipenem (IPM in sub-minimum inhibitory concentrations against 22 clinical strains of MRSA and CNS. The checkerboard method showed synergism of VAN/RIF and VAN/SXT against two and three of the 22 strains, respectively. The combination of VAN with IPM showed synergistic effects against 21 out of 22 strains by the E-test method. Four strains were analyzed by the time-kill curve method and synergistic activity was observed with VAN/SXT, VAN/RIF and especially VAN/IPM in sub-inhibitory concentrations. It would be interesting to determine if synergy occurs in vivo. Evidence of in vivo synergy could lead to a reduction of the standard VAN dosage or treatment time.

Methicillin-resistant Staphylococcus aureus: Prevalence, incidence, risk factors, and effects on survival of patients in a specialist palliative care unit: A prospective observational study.

Science.gov (United States)

Gleeson, Aoife; Larkin, Philip; Walsh, Cathal; O'Sullivan, Niamh

2016-04-01

Little is known about the impact of methicillin-resistant Staphylococcus aureus in palliative care settings. To date, the clinical impact of methicillin-resistant Staphylococcus aureus in palliative care is unknown. To determine prevalence and incidence of methicillin-resistant Staphylococcus aureus colonisation in a specialist palliative care setting, to identify risk factors for methicillin-resistant Staphylococcus aureus colonisation, to determine the eradication success rate and to determine the impact of methicillin-resistant Staphylococcus aureus on survival. Prospective cohort study. Data were collected for consecutive admissions to an inpatient palliative care service. Patients were screened for methicillin-resistant Staphylococcus aureus colonisation on admission and 1 week post admission. Methicillin-resistant Staphylococcus aureus eradication was attempted in methicillin-resistant Staphylococcus aureus positive patients. Data were collected from 609 admissions for 466 individual patients. Admission screening data were available in 95.5%. Prevalence of methicillin-resistant Staphylococcus aureus colonisation was 11.59% (54 patients). One week incidence of methicillin-resistant Staphylococcus aureus colonisation was 1.2%. Risk factors for methicillin-resistant Staphylococcus aureus colonisation were determined using Chi-Squared test and included high Waterlow score (p resistant Staphylococcus aureus status prior to admission (p resistant Staphylococcus aureus was eradicated in 8.1% of admissions, while 46 patients commenced on the protocol (62.2%) died before completing it. Methicillin-resistant Staphylococcus aureus did not significantly impact survival but was significantly associated with having infection episodes and longer length of stay. This study identified risk factors for methicillin-resistant Staphylococcus aureus colonisation in palliative care patients. Methicillin-resistant Staphylococcus aureus was eradicated in 8.1% of patients. Hence

Origins and Evolution of Methicillin-Resistant Staphylococcus aureus Clonal Lineages

DEFF Research Database (Denmark)

Gomes, AR; Westh, Henrik; Lancastre, H de

2006-01-01

Most methicillin-resistant Staphylococcus aureus (MRSA) isolates identified among blood isolates collected in Denmark between 1957 and 1970 belonged to either phage group III or the closely related 83A complex and had a PSTM antibiotype (resistance to penicillin [P], streptomycin [S], tetracycline...... [T], and methicillin [M]). Recently, some of these isolates were shown to have the same genetic backgrounds as contemporary epidemic MRSA isolates, and Danish methicillin-susceptible S. aureus (MSSA) isolates from the 1960s with a PST antibiotype were proposed to have been the recipients of the mec...

Characterization of staphylococci in urban wastewater treatment plants in Spain, with detection of methicillin resistant Staphylococcus aureus ST398

International Nuclear Information System (INIS)

Gómez, Paula; Lozano, Carmen; Benito, Daniel; Estepa, Vanesa; Tenorio, Carmen; Zarazaga, Myriam; Torres, Carmen

2016-01-01

The objective of this study was to determine the prevalence of Staphylococcus in urban wastewater treatment plants (UWTP) of La Rioja (Spain), and to characterize de obtained isolates. 16 wastewater samples (8 influent, 8 effluent) of six UWTPs were seeded on mannitol-salt-agar and oxacillin-resistance-screening-agar-base for staphylococci and methicillin-resistant Staphylococcus aureus recovery. Antimicrobial susceptibility profile was determined for 16 antibiotics and the presence of 35 antimicrobial resistance genes and 14 virulence genes by PCR. S. aureus was typed by spa, agr, and multilocus-sequence-typing, and the presence of immune-evasion-genes cluster was analyzed. Staphylococcus spp. were detected in 13 of 16 tested wastewater samples (81%), although the number of CFU/mL decreased after treatment. 40 staphylococci were recovered (1–5/sample), and 8 of them were identified as S. aureus being typed as (number of strains): spa-t011/agr-II/ST398 (1), spa-t002/agr-II/ST5 (2), spa-t3262/agr-II/ST5 (1), spa-t605/agr-II/ST126 (3), and spa-t878/agr-III/ST2849 (1). S. aureus ST398 strain was methicillin-resistant and showed a multidrug resistance phenotype. Virulence genes tst, etd, sea, sec, seg, sei, sem, sen, seo, and seu, were detected among S. aureus and only ST5 strains showed genes of immune evasion cluster. Thirty-two coagulase-negative Staphylococcus of 12 different species were recovered (number of strains): Staphylococcus equorum (7), Staphylococcus vitulinus (4), Staphylococcus lentus (4), Staphylococcus sciuri (4), Staphylococcus fleurettii (2), Staphylococcus haemolyticus (2), Staphylococcus hominis (2), Staphylococcus saprophyticus (2), Staphylococcus succinus (2), Staphylococcus capitis (1), Staphylococcus cohnii (1), and Staphylococcus epidermidis (1). Five presented a multidrug resistance phenotype. The following resistance and virulence genes were found: mecA, lnu(A), vga(A), tet(K), erm(C), msr(A)/(B), mph(C), tst, and sem. We found that

Spontaneous methicillin-resistant Staphylococcus aureus (MRSA) meningitis.

Science.gov (United States)

Longhurst, William D; Sheele, Johnathan M

2018-05-01

Spontaneous methicillin-resistant Staphylococcus aureus (MRSA) meningitis is extremely rare and has a high mortality rate. We report a case of MRSA meningitis in an otherwise healthy young adult female with no recent trauma or neurosurgical interventions. Despite antibiotics she suffered a vasculitis-induced cerebral vascular ischemic event. Copyright © 2018 Elsevier Inc. All rights reserved.

Marinopyrrole Derivatives as Potential Antibiotic Agents against Methicillin-Resistant Staphylococcus aureus (II

Directory of Open Access Journals (Sweden)

Rongshi Li

2013-08-01

Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA continues to be a major problem, causing severe and intractable infections worldwide. MRSA is resistant to all beta-lactam antibiotics, and alternative treatments are limited. A very limited number of new antibiotics have been discovered over the last half-century, novel agents for the treatment of MRSA infections are urgently needed. Marinopyrrole A was reported to show antibiotic activity against MRSA in 2008. After we reported the first total synthesis of (±-marinopyrrole A, we designed and synthesized a series of marinopyrrole derivatives. Our structure activity relationship (SAR studies of these novel derivatives against a panel of Gram-positive pathogens in antibacterial assays have revealed that a para-trifluoromethyl analog (33 of marinopyrrole A is ≥63-, 8-, and 4-fold more potent than vancomycin against methicillin-resistant Staphylococcus epidermidis (MRSE, methicillin-susceptible Staphylococcus aureus (MSSA and MRSA, respectively. The results provide valuable information in the search for new-generation antibiotics.

Community-associated methicillin-resistant Staphylococcus aureus causing chronic pneumonia.

Science.gov (United States)

Enayet, Iram; Nazeri, Ali; Johnson, Leonard B; Riederer, Kathleen; Pawlak, Joan; Saravolatz, Louis D

2006-04-01

A young woman presented with pneumonia of a 3-month duration with predominantly nodular pulmonary infiltrates. Methicillin-resistant Staphylococcus aureus was identified in multiple cultures of sputum specimens. According to findings of pulsed-field gel electrophoresis, the isolate was identical to USA 300 and carried a type IV Staphylococcus cassette chromosome mec type IV gene and the genes for Panton-Valentine leukocidin.

Methicillin-resistant Staphylococcus aureus transmission

DEFF Research Database (Denmark)

Andersen, Leif Percival; Nielsen, Xiaohui

2015-01-01

INTRODUCTION: Even though methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of nosocomial infections, it may often be difficult to evaluate the exact route of transmission. METHODS: In this study, we describe four cases of nosocomial transmission of MRSA in a hospital with a low...... increase the risk of contaminating hands, arms and the front of the uniform. Hand hygiene is therefore essential, but the use of protection gowns with long sleeves is also important in order to prevent transmission of MRSA. After culture of MRSA and implementation of specific precautions to prevent...

Antibiotic resistant pattern of methicillin resistant and sensitive Staphylococcus aureus isolated from patients durining 2009-2010, Ahvaz, Iran.

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N Parhizgari

2013-12-01

Full Text Available Abstract Background & aim: Staphylococcus aureus is one of the most important nosocomial infecting agents resistant to commonly used antibiotics. Nowadays, methicillin-resistant S. aureus (MRSA is considered one of the main causes of nosocomial infections. The aim of this study was to identify the antibiotic resistance pattern of methicicllin- resistant and susceptible strains in Ahwaz, Iran. Methods: In the present cross - sectional study, a number of 255 clinically suspected cases of Staphylococcus aureus were collected during a 19 month period. The bacteria were investigated using standard biochemical tests such as catalase, mannitol fermentation, coagulase and Dnase. Sensitive strains were confirmed by disk diffusion method compared to commonly used antibiotics. The collected data were analyzed using descriptive statistical tests. Results: of 255 suspected cases, 180 were confirmed as S.aureus, a total of 59 strains of S. aureus (2/37 percent were resistant to methicillin. Resistance to S. aureus strains resistant to methicillin included: chloramphenicol (3.38%, rifampin (45.76%, norfloxacin (89.83%, gentamicin (89.83%, ciprofloxacin, (91.52%, azithromycin, (88.13%, cotrimoxazole (86.44% and all isolates strains were sensitive to vancomycin and nitrofurantoin. A total of 10 different patterns of antibiotic resistance in methicillin-resistant Staphylococcus aureus strains were identified. Conclusion: Expression of new resistance factor in nosocomial infection is one of the major challenges in treating these infections. This study showed a high prevalence of resistance against some class of antibiotics in MRSA isolated from Imam Khomeini and Golestan hospital of Ahwaz, Iran. Key words: Nosocomial infection, Methicillin Resistant Staphylococcus aureus (MRSA, Antibiotic Resistant Pattern

Methicillin-resistant Staphylococcus aureus in Pig Farming

OpenAIRE

Voss, Andreas; Loeffen, Frans; Bakker, Judith; Klaassen, Corne; Wulf, Mireille

2005-01-01

We conducted a study among a group of 26 regional pig farmers to determine the methicillin-resistant Staphylococcus aureus prevalence rate and found it was >760 times greater than the rate of patients admitted to Dutch hospitals. While spa-type t108 is apparently a more widespread clone among pig farmers and their environment, we did find other spa-types.

[Prevalence and predisposing factors of methicillin-resistant Staphylococcus aureus in long-term care facilities. An international view].

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Szabó, Rita

2016-07-03

Methicillin-resistant Staphylococcus aureus is one of the most important pathogens of healthcare and long-term care-associated infections over the world, resulting high morbidity, mortality and extra costs in these settings. The authors analyze the prevalence and predisposing factors of methicillin-resistant Staphylococcus aureus in long-term care facilities. Systematic review using PubMed, ScienceDirect and Cochrane Library CENTRAL databases between January 1, 2006 and December 31, 2015 was performed. In the past ten years methicillin-resistant Staphylococcus aureus prevalence in European long-term care facilities (12.6%) was lower than in North America (33.9%). The most frequent predisposing factor was previous antimicrobial therapy, hospital admission and infection/colonisation, chronic wounds, and high care need. Based on the results, the prevention and control of methicillin-resistant Staphylococcus aureus is an important public health priority in the European and Hungarian long-term care facilities.

Transmission of methicillin-resistant Staphylococcus aureus to household contacts

NARCIS (Netherlands)

F.P.N. Mollema (Femke); J.H. Richardus (Jan Hendrik); M.D. Behrendt (Myra); N. Vaessen (Norbert); W. Lodder; W. Hendriks; H.A. Verbrugh (Henri); A. Voss (Andreas)

2010-01-01

textabstractThe frequency of and risk factors for methicillin-resistant Staphylococcus aureus (MRSA) transmission from a MRSA index person to household contacts were assessed in this prospective study. Between January 2005 and December 2007, 62 newly diagnosed MRSA index persons (46 patients and 16

In-vitro antioxidant and antibacterial activities of Xanthium strumarium L. extracts on methicillin-susceptible and methicillin-resistant Staphylococcus aureus

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Javad Sharifi Rad

2013-01-01

Results and Conclusions: The IC 50 values of the extract were 0.02 mg/mL and 0.09 mg/mL for the antioxidant and DPPH-scavenging capacity, respectively. X. strumarium extract affected both methicillin-sensitive Staphylococcus aureus and MRSA, though antibacterial activity was more effective on methicillin-susceptible S. aureus spp. The antibacterial and antioxidant activities exhibited by the methanol extract may justify the traditional use of this plant as a folk remedy worldwide.

Evolutionary dynamics of methicillin-resistant Staphylococcus aureus within a healthcare system

NARCIS (Netherlands)

Hsu, Li-Yang; Harris, Simon R.; Chlebowicz, Monika A.; Lindsay, Jodi A.; Koh, Tse-Hsien; Krishnan, Prabha; Tan, Thean-Yen; Hon, Pei-Yun; Grubb, Warren B.; Bentley, Stephen D.; Parkhill, Julian; Peacock, Sharon J.; Holden, Matthew T. G.

2015-01-01

Background: In the past decade, several countries have seen gradual replacement of endemic multi-resistant healthcare-associated methicillin-resistant Staphylococcus aureus (MRSA) with clones that are more susceptible to antibiotic treatment. One example is Singapore, where MRSA ST239, the dominant

Methicillin resistance in Staphylococcus aureus : a review of the ...

African Journals Online (AJOL)

Methicillin resistance in Staphylococcus aureus : a review of the molecular epidemiology, clinical significance and laboratory detection methods. ... Added to this burden is the emergence of more virulent strains of community-associated MRSA (CAMRSA) which at the turn of the century, has been increasingly reported to ...

In vitro transfer of methicillin resistance determinants mecA from methicillin resistant Staphylococcus aureus (MRSA) to methicillin susceptible Staphylococcus aureus (MSSA).

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Bitrus, Asinamai Athliamai; Zunita, Zakaria; Bejo, Siti Khairani; Othman, Sarah; Nadzir, Nur Adilah Ahmad

2017-04-04

Staphylococcus aureus more than any other human pathogen is a better model for the study of the adaptive evolution of bacterial resistance to antibiotics, as it has demonstrated a remarkable ability in its response to new antibiotics. This study was designed to investigate the in vitro transfer of mecA gene from methicillin resistant S. aureus to methicillin susceptible S. aureus. The recipient transconjugants were resistant to erythromycin, cefpodoxime and were mecA positive. PCR amplification of mecA after mix culture plating on Luria Bertani agar containing 100 μg/mL showed that 75% of the donor and 58.3% of the recipient transconjugants were mecA positive. Additionally, 61.5% of both the donor cells and recipient transconjugants were mecA positive, while 46.2% and 41.75% of both donor and recipient transconjugants were mecA positive on LB agar containing 50 μg/mL and 30 μg/mL respectively. In this study, the direction of transfer of phenotypic resistance as well as mecA was observed to have occurred from the donor to the recipient strains. This study affirmed the importance of horizontal transfer events in the dissemination of antibiotics resistance among different strains of MRSA.

Staphylococcus species and their Methicillin-Resistance in 7424 Blood Cultures for Suspected Bloodstream Infections

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Ariana ALMAŞ

2011-06-01

Full Text Available Objectives: The aim of this study was to evaluate the distribution of Staphylococcus species in bloodstream infections and to assess their susceptibility to methicillin. Material and Methods: Between January 1st 2008 - December 31st 2010, 7424 blood culture sets were submitted to the Laboratory Department of the Hospital for Clinical Infectious Diseases in Cluj-Napoca, Romania. The blood cultures were performed using BacT/Alert until January 2010 and BacT/Alert 3D automated system (bioMérieux after that date. The blood culture bottles were incubated at 37°C in a continuously monitoring system for up to 7 days. The strain identifications were performed by conventional methods, ApiStaph galleries and Vitek 2 Compact system. Susceptibility to methicillin was determined by disk diffusion method with cefoxitin disk and by using Vitek 2 Compact system. Results: From the total number of performed blood cultures, 568 were positive with Staphylococcus species. From 168 bacteriemic episodes 103 were with Staphylococcus aureus. Among 65 coagulase-negative staphylococci isolates, Staphylococcus epidermidis was the most frequently isolated species (34, followed by Staphylococcus hominis (15, Staphylococcus haemolyticus (8, Staphylococcus saprophyticus (3, Staphylococcus cohnii (1, Staphylococcus auricularis (1, and 3 strains that were not identified at species level. Methicillin resistance was encountered in 53.40% of Staphylococcus aureus strains and in 80% of coagulase-negative staphylococci. Conclusions: An important percentage of blood cultures were contaminated with Staphylococcus species. The main species identified in true bacteriemia cases were Staphylococcus aureus and Staphylococcus epidermidis. The percentage of methicillin-resistance, proved to be high not only for coagulase-negative staphylococci but also for Staphylococcus aureus.

TOC-39, a novel parenteral broad-spectrum cephalosporin with excellent activity against methicillin-resistant Staphylococcus aureus.

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Hanaki, H; Akagi, H; Masaru, Y; Otani, T; Hyodo, A; Hiramatsu, K

1995-01-01

TOC-39, a new parenteral cephalosporin, is a hydroxyimino-type cephem antibiotic with vinylthio-pyridyl moiety at the 3 position. TOC-39 was evaluated for antibacterial activity against various clinically isolated strains. TOC-39 had excellent activity, stronger than that of methicillin, oxacillin, the cephalosporins tested, imipenem, gentamicin, minocycline, tobramycin, ofloxacin, and ciprofloxacin against methicillin-resistant Staphylococcus aureus (MRSA) and had an MIC comparable to that of vancomycin (the MICs of TOC-39 and vancomycin for 90% of the strains tested were 3.13 and 1.56 micrograms/ml, respectively). Against Enterococcus faecalis strains, which are resistant to cephalosporins, TOC-39 was twice as active as ampicillin. Against methicillin-susceptible S. aureus, coagulase-negative Staphylococcus spp., and Streptococcus pneumoniae, TOC-39 was twice as active as or more active than cefotiam, ceftazidime, flomoxef, and cefpirome. Against Streptococcus pyogenes, TOC-39 was superior to cefotiam, ceftazidime, and flomoxef and was similar to cefpirome. In addition, the activity of TOC-39 was equal to or greater than that of cefotiam, ceftazidime, flomoxef, and cefpirome against Haemophilus influenzae, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, and Morganella morganii. In terms of bactericidal effect against MRSA, TOC-39 was superior to vancomycin. No mutant resistant to TOC-39 or vancomycin was obtained from susceptible MRSA strains. In murine systemic infection models, TOC-39 showed potent activity against S. aureus and E. coli. Against highly MRSA, the activity of TOC-39 was comparable to that of vancomycin. PMID:7625799

In Vitro Antibacterial and Antibiotic Resistance Modifying Effect of Bioactive Plant Extracts on Methicillin-Resistant Staphylococcus epidermidis

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Romana Chovanová

2013-01-01

Full Text Available The crude extracts of plants from Asteraceae and Lamiaceae family and essential oils from Salvia officinalis and Salvia sclarea were studied for their antibacterial as well as antibiotic resistance modifying activity. Using disc diffusion and broth microdilution assays we determined higher antibacterial effect of three Salvia spp. and by evaluating the leakage of 260 nm absorbing material we detected effect of extracts and, namely, of essential oils on the disruption of cytoplasmic membrane. The evaluation of in vitro interactions between plant extracts and oxacillin described in terms of fractional inhibitory concentration (FIC indices revealed synergistic or additive effects of plant extracts and clearly synergistic effects of essential oil from Salvia officinalis with oxacillin in methicillin-resistant Staphylococcus epidermidis.

Rapid control of a methicillin resistant Staphylococcus aureus (MRSA) outbreak in a medical surgical intensive care unit (ICU).

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Khan, Anjum; Lampitoc, Marianita; Salaripour, Maryam; McKernan, Patricia; Devlin, Roslyn; Muller, Matthew P

2009-01-01

Outbreaks of methicillin resistant Staphylococcus aureus in the intensive care unit setting can be prolonged and difficult to control. This report describes the rapid control of an outbreak of methicillin resistant Staphylococcus aureus in a 24-bed open-concept medical surgical intensive care unit with a baseline methicillin resistant Staphylococcus aureus acquisition rate of 1.5 cases per 1000 patient days. This institution's infection control policy mandates an outbreak investigation if two cases of hospital-acquired methicillin resistant Staphylococcus aureus colonization or infection are identified in an intensive care unit within a four-week period. In July 2007, methicillin resistant Staphylococcus aureus was identified in the sputum of two patients within a one-week period. Screening of all patients in the intensive care unit identified one additional case and a fourth case was identified from a clinical specimen before control measures were implemented. Initial control measures included healthcare worker education, enhanced surveillance, patient cohorting, and enhanced environmental cleaning. Despite these measures, three more cases occurred. All patients were then placed in contact isolation, healthcare workers were screened, and the nursing staff was cohorted. After two weeks without a case, two additional cases were identified. Decolonization of all positive patients was initiated. No further cases occurred over a five-week period and the outbreak was declared over. The outbreak resulted in nine cases of methicillin resistant Staphylococcus aureus colonization (n = 8) or infection (n = 1) over an 11-week period. Only one of 175 healthcare workers was colonized and it was not the outbreak strain. Early detection and the stepwise addition of infection control measures resulted in the rapid control of an outbreak of methicillin resistant Staphylococcus aureus in a medical surgical intensive care unit without unit closure. A low threshold of suspicion and

Reversal of methicillin resistance in Staphylococcus aureus by thioridazine

DEFF Research Database (Denmark)

Klitgaard, Janne K; Skov, Marianne N; Kallipolitis, Birgitte H

2008-01-01

of thioridazine in the presence of a fixed amount of oxacillin. Furthermore, the protein level of PBP2a was reduced when bacteria were treated with the combination of oxacillin and thioridazine. The two drugs also affected the mRNA level of the beta-lactamase gene, blaZ. Conclusions The present study indicates......Objectives Thioridazine has been shown to reverse oxacillin resistance in methicillin-resistant Staphylococcus aureus (MRSA) in vitro. The aim of this study was to investigate whether thioridazine alone or in combination with oxacillin affects the transcription of the methicillin resistance gene...... blotting in the presence of thioridazine and oxacillin. Results We observed an increased susceptibility of MRSA towards oxacillin in the presence of thioridazine compared with bacteria grown with oxacillin or thioridazine alone. Transcription of mecA was reduced with increasing concentrations...

Toxic shock syndrome due to community-acquired methicillin-resistant Staphylococcus aureus infection: Two case reports and a literature review in Japan.

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Sada, Ryuichi; Fukuda, Saori; Ishimaru, Hiroyasu

2017-01-01

Community-acquired methicillin-resistant Staphylococcus aureus has been spreading worldwide, including in Japan. However, few cases of toxic shock syndrome caused by Community-acquired methicillin-resistant Staphylococcus aureus have been reported in Japan. We report 2 cases, in middle-aged women, of toxic shock syndrome due to Community-acquired methicillin-resistant Staphylococcus aureus via a vaginal portal of entry. The first patient had used a tampon and the second patient had vaginitis due to a cleft narrowing associated with vulvar lichen sclerosus. Both patients were admitted to our hospital with septic shock and severe acute kidney injury and subsequently recovered with appropriate antibiotic treatment. In our review of the literature, 8 cases of toxic shock syndrome caused by Community-acquired methicillin-resistant Staphylococcus aureus were reported in Japan. In these 8 cases, the main portals of entry were the skin and respiratory tract; however, the portal of entry of Community-acquired methicillin-resistant Staphylococcus aureus from a vaginal lesion has not been reported in Japan previously.

Toxic shock syndrome due to community-acquired methicillin-resistant Staphylococcus aureus infection: Two case reports and a literature review in Japan

OpenAIRE

Sada, Ryuichi; Fukuda, Saori; Ishimaru, Hiroyasu

2017-01-01

Community-acquired methicillin-resistant Staphylococcus aureus has been spreading worldwide, including in Japan. However, few cases of toxic shock syndrome caused by Community-acquired methicillin-resistant Staphylococcus aureus have been reported in Japan. We report 2 cases, in middle-aged women, of toxic shock syndrome due to Community-acquired methicillin-resistant Staphylococcus aureus via a vaginal portal of entry. The first patient had used a tampon and the second patient had vaginitis ...

Prevalence of Methicillin Resistant Staphylococcus aureus in pyogenic community and hospital acquired skin and soft tissues infections

International Nuclear Information System (INIS)

Ahmad, M. K.; Asrar, A.

2014-01-01

Objective: To determine the percentage and frequency of Methicillin Resistant Staphylococcus aureus in community and hospital-acquired pyogenic skin and soft tissue infections. Methods: The descriptive cross-sectional study was conducted at the Dermatology Department of Combined Military Hospital, Abbottabad, from June 2009 to March 2010, and comprised 144 community-acquired and 54 hospital-acquired skin and soft tissue infections. Pus swabs from the infected lesions one from each individual were sent to laboratory for culture and sensitivity tests. Methicillin resistance was detected by 1 (mu) g oxacillin disk. Organisms were labelled methicillin-resistant once the inhibition zone for oxocillin was less than 10 mm. Data analysis was done by using SPSS 20. Results: Of the 198 patients in the study, 98(49.5%) were males and 100(50.5%) were females, with an overall mean age of 33.7+-14.8144 years. There were 144(72.72%) community-acquired infections and 54(27.27%) had hospital-acquired infections. Community-acquired Methicillin Resistant Staphylococcus aureus numbered 40(27.8%) and hospital-acquired ones numbered 26(48.1%). Conclusion: Prevalence of Methicillin Resistant Staphylococcus aureus in community and hospital-acquired pyogenic skin and soft tissue infections was high. (author)

The Epidemiology of Methicillin-Resistant Staphylococcus aureus (MRSA) in Germany

NARCIS (Netherlands)

Koeck, Robin; Mellmann, Alexander; Schaumburg, Frieder; Friedrich, Alexander W.; Kipp, Frank; Becker, Karsten

2011-01-01

Background: For decades, methicillin-resistant Staphylococcus aureus (MRSA) has been a major cause of infection in hospitals and nursing homes (health care-associated MRSA, HA-MRSA). Beginning in the late 1990s, many countries have also experienced a rising incidence of MRSA infection outside of the

Unraveling the dynamics of community-associated methicillin-resistant Staphylococcus aureus

NARCIS (Netherlands)

Bootsma, M.C.; Bonten, M.J.M.

2013-01-01

Since the first description of the community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) strain USA300 [1] in the 1990s, this pathogen has emerged worldwide [2]. Within a decade, USA300 has become the most prevalent cause of community-acquired S. aureus infections in many

Treatment of methicillin-resistant Staphylococcus aureus in Latin America

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Carlos M Luna

Full Text Available The global spread of methicillin-resistant Staphylococcus aureus (MRSA means it is now a pathogen of worldwide public health concern. Within Latin America, MRSA is highly prevalent, with the proportion of S. aureus isolates that are methicillin-resistant on the rise, yet resources for managing the infection are limited. While several guidelines exist for the treatment of MRSA infections, many are written for the North American or European setting and need adaptation for use in Latin America. In this article, we aim to emphasize the importance of appropriate treatment of MRSA in the healthcare and community settings of Latin America. We present a summary of the available guidelines and antibiotics, and discuss particular considerations for clinicians treating MRSA in Latin America

Zinc resistance within swine associated methicillin resistant Staphylococcus aureus (MRSA) isolates in the USA is associated with MLST lineage

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Zinc resistance in livestock-associated methicillin resistant Staphylococcus aureus (LA-MRSA) is mediated by the czrC gene co-located with the mecA gene, encoding methicillin resistance, on the type V SCCmec element. Since the czrC gene and the mecA gene are co-located on the SCCmec element, it has ...

Identification and characterization of methicillin-resistant Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus haemolyticus and Staphylococcus pettenkoferi from a small animal clinic.

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Weiss, Sonja; Kadlec, Kristina; Fessler, Andrea T; Schwarz, Stefan

2013-12-27

The aim of this study was to isolate and characterize methicillin-resistant staphylococci (MRS) in a small animal clinic and to investigate their distribution and possible transmission. Swabs (n=72) were taken from hospitalized pets, the environment and employees of a small animal clinic and screened for the presence of MRS. The staphylococcal species was confirmed biochemically or by 16S rDNA sequencing. Susceptibility to antimicrobial agents was tested by broth dilution. The presence of mecA and other resistance genes was confirmed by PCR. Molecular typing of the isolates followed standard procedures. In total, 34 MRS belonging to the four species Staphylococcus aureus (n=5), Staphylococcus epidermidis (n=21), Staphylococcus haemolyticus (n=6) or Staphylococcus pettenkoferi (n=2) were isolated. All isolates were multidrug-resistant with resistance to at least three classes of antimicrobial agents. Among the five methicillin-resistant S. aureus (MRSA) isolates, four belonged to the clonal complex CC398; two of them were isolated from cats, the remaining two from pet cages. Overall, the MRS isolates differed in their characteristics, except for one S. epidermidis clone (n=9) isolated from hospitalized cats without clinical staphylococcal infections, pet cages, the clinic environment as well as from a healthy employee. This MRSE clone was resistant to 10 classes of antimicrobial agents, including aminocyclitols, β-lactams, fluoroquinolones, lincosamides, macrolides, phenicols, pleuromutilins, sulfonamides, tetracyclines and trimethoprim. These findings suggest a possible transmission of specific MRS isolates between animal patients, employees and the clinic environment. Copyright © 2013 Elsevier B.V. All rights reserved.

Prevalence and antibiogram of methicillin resistant Staphylococcus aureus isolated from medical device-related infections; a retrospective study in Lahore, Pakistan

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Muhammad Sohail

Full Text Available Abstract INTRODUCTION: With the advancement of medicine and surgery, various types of medical devices have become part of treatment strategies. METHODS: Identification and antimicrobial sensitivity testing were done according to CLSI guidelines following standard microbiological practices. RESULTS: Urinary catheter infections (31% were most frequent followed by central venous catheter (18% and orthopedic implants (15%. Methicillin resistant Staphylococcus aureus (MRSA was a major cause of device-related infection after Escherichia coli (21%; other pathogens were Klebsiella pneumoniae (14%, Pseudomonas spp. (10%, Acinetobacter spp. (8% and Candida species (7%. None of MRSA was resistant to vancomycin (MIC ≥16µg/mL. Resistance rates were 98% and 97% for ofloxacin and ciprofloxacin, respectively. CONCLUSIONS Escherichia coli and MRSA are major pathogens of medical device-related infections.

Methicillin-resistant Staphylococcus aureus emerged long before the introduction of methicillin into clinical practice.

Science.gov (United States)

Harkins, Catriona P; Pichon, Bruno; Doumith, Michel; Parkhill, Julian; Westh, Henrik; Tomasz, Alexander; de Lencastre, Herminia; Bentley, Stephen D; Kearns, Angela M; Holden, Matthew T G

2017-07-20

The spread of drug-resistant bacterial pathogens poses a major threat to global health. It is widely recognised that the widespread use of antibiotics has generated selective pressures that have driven the emergence of resistant strains. Methicillin-resistant Staphylococcus aureus (MRSA) was first observed in 1960, less than one year after the introduction of this second generation beta-lactam antibiotic into clinical practice. Epidemiological evidence has always suggested that resistance arose around this period, when the mecA gene encoding methicillin resistance carried on an SCCmec element, was horizontally transferred to an intrinsically sensitive strain of S. aureus. Whole genome sequencing a collection of the first MRSA isolates allows us to reconstruct the evolutionary history of the archetypal MRSA. We apply Bayesian phylogenetic reconstruction to infer the time point at which this early MRSA lineage arose and when SCCmec was acquired. MRSA emerged in the mid-1940s, following the acquisition of an ancestral type I SCCmec element, some 14 years before the first therapeutic use of methicillin. Methicillin use was not the original driving factor in the evolution of MRSA as previously thought. Rather it was the widespread use of first generation beta-lactams such as penicillin in the years prior to the introduction of methicillin, which selected for S. aureus strains carrying the mecA determinant. Crucially this highlights how new drugs, introduced to circumvent known resistance mechanisms, can be rendered ineffective by unrecognised adaptations in the bacterial population due to the historic selective landscape created by the widespread use of other antibiotics.

Epidemic Increase in Methicillin-resistant Staphylococcus aureus in Copenhagen

DEFF Research Database (Denmark)

Westh, Henrik; Boye, Kit; Bartels, Mette Damkjær

2006-01-01

INTRODUCTION: We have found an epidemic increase in methicillin-resistant Staphylococcus aureus (MRSA) in Copenhagen. The increase has a complex background and involves hospitals, nursing homes and persons nursed in their own home. MATERIAL AND METHODS: We found 33 MRSA patients in 2003 and 121...... in 2004. All isolates have been spa-typed and epidemiologic information collected. RESULTS: The number of MRSA cases has a doubling time of about six months. The epidemic has been caused by many different MRSA types and 31 staphylococcus protein A genotypes (spa types). MRSA has caused several hospital...

Characterization of methicillin-resistant Staphylococcus aureus Sequence Type 398

DEFF Research Database (Denmark)

Christiansen, Mette Theilgaard

Staphylococcus aureus is an opportunistic pathogen that colonizes the nares and skin surfaces of several animal species, including man. S. aureus can cause a wide variety of infections ranging from superficial soft tissue and skin infections to severe and deadly systemic infections. Traditionally S....... aureus and methicillin-resistant Staphylococcus aureus (MRSA) have been associated with hospitals, but during the past decades MRSA has emerged in the community and now a new branch of MRSA has been found in association with livestock (LA-MRSA). A specific lineage (multilocus sequence type 398 (ST398...

Molecular Characterization of Methicillin-Resistant Staphylococcus aureus Causing Fatal Purulent Pericarditis.

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Kumar, Vasudevan Anil; Nair, Nisha; Thachathodiyl, Rajesh; Nandakumar, Aswathy; Dinesh, Kavitha R; Thatcher, Eileen; Karim, Shamsul; Biswas, Raja

2013-07-01

Though pericardial disease is common in patients with renal disease, purulent pericarditis is very rare. We report a fatal case of purulent pericarditis and sepsis due to methicillin-resistant Staphylococcus aureus in a 78-year-old male with systemic hypertension and renal disease along with the molecular characterization of its resistant mechanism.

Novel Multiplex PCR Assay for Detection of Chlorhexidine-Quaternary Ammonium, Mupirocin, and Methicillin Resistance Genes, with Simultaneous Discrimination of Staphylococcus aureus from Coagulase-Negative Staphylococci.

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McClure, Jo-Ann; Zaal DeLongchamp, Johanna; Conly, John M; Zhang, Kunyan

2017-06-01

Methicillin-resistant Staphylococcus aureus (MRSA) is a clinically significant pathogen that is resistant to a wide variety of antibiotics and responsible for a large number of nosocomial infections worldwide. The Agency for Healthcare Research and Quality and the Centers for Disease Control and Prevention recently recommended the adoption of universal mupirocin-chlorhexidine decolonization of all admitted intensive care unit patients rather than MRSA screening with targeted treatments, which raises a serious concern about the selection of resistance to mupirocin and chlorhexidine in strains of staphylococci. Thus, a simple, rapid, and reliable approach is paramount in monitoring the prevalence of resistance to these agents. We developed a simple multiplex PCR assay capable of screening Staphylococcus isolates for the presence of antiseptic resistance genes for chlorhexidine and quaternary ammonium compounds, as well as mupirocin and methicillin resistance genes, while simultaneously discriminating S. aureus from coagulase-negative staphylococci (CoNS). The assay incorporates 7 PCR targets, including the Staphylococcus 16S rRNA gene (specifically detecting Staphylococcus spp.), nuc (distinguishing S. aureus from CoNS), mecA (distinguishing MRSA from methicillin-susceptible S. aureus ), mupA and mupB (identifying high-level mupirocin resistance), and qac and smr (identifying chlorhexidine and quaternary ammonium resistance). Our assay demonstrated 100% sensitivity, specificity, and accuracy in a total of 23 variant antiseptic- and/or antibiotic-resistant control strains. Further validation of our assay using 378 randomly selected and previously well-characterized local clinical isolates confirmed its feasibility and practicality. This may prove to be a useful tool for multidrug-resistant Staphylococcus monitoring in clinical laboratories, particularly in the wake of increased chlorhexidine and mupirocin treatments. Copyright © 2017 American Society for Microbiology.

DAYA HAMBAT SARI TANAMAN OBAT TERHADAP PERTUMBUHAN BAKTERI STRAIN Methicillin Resistant Staphylococcus aureus (MRSA

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Dwi Hilda Putri

2016-09-01

Full Text Available Staphylococcus aureus infection can be treated with Methicilin, β lactam class of antibiotics that have drug targets in the cell wall. Bacteria S. aureus that is resistant to methicillin called methicillin-resistant Staphylococcus aureus (MRSA. One alternative that can be used in strains of antibiotic-resistant bacteria that have this is to use medicinal plants. This study aimed to know the ability of medicinal plant extracts inhibit the growth of bacterial strains of MRSA. This kind of research is experimental research. Medicinal plants tested were Garlic, Turmeric, Aloe Vera, Daun Salam, Curcuma, Ginger, Betel Leaf and Alpinia galanga. As a control, which is used Amphicillin, β lactam antibiotic class. The method used to determine the diameter of inhibition area of medicinal plant extracts is paper diffusion method. The results showed that all medicinal plants can inhibit bacterial growth of MRSA strains characterized by the inhibition zone formed on each treatment. The ability of garlic and turmeric extract better than Amphicillin and other medicinal plants to inhibit bacterial growth of MRSA strains. Kata kunci: inhibit,  growth, bacteria, methicillin resistant staphylococcus aureus (MRSA

Presence of Methicillin Resistant Staphylococcus aureus (MRSA) in sewage treatment plant.

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Boopathy, Raj

2017-09-01

The presence of antibiotic resistant bacteria and antibiotic resistance genes in rural sewage treatment plants are not well reported in the literature. The aim of the present study was to study the frequency occurrence of Methicillin Resistant Staphylococcus aureus (MRSA) in a rural sewage treatment plant. This study was conducted using raw sewage as well as treated sewage from a small town sewage treatment plant in rural southeast Louisiana of USA. Results showed the presence of MRSA consistently in both raw and treated sewage. The presence of mecA gene responsible for methicillin resistance was confirmed in the raw and treated sewage water samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

Antimicrobial blue light inactivation of Methicillin-resistant Staphylococcus aureus

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Wang, Yucheng; Dai, Tianhong; Gu, Ying

2016-10-01

Background: With the increasing emergence of multidrug-resistant (MDR) bacterial strains, there is a pressing need for the development of alternative treatment for infections. Antimicrobial blue light (aBL) has provided a simple and effective approach. Methods: We first investigated the effectiveness of aBL (415 nm) inactivation of USA300 LAClux (a communityacquired Methicillin-resistant Staphylococcus aureus strain) both in the planktonic and biofilm forms. The survival of the bacteria in suspensions was determined by serial dilution and that of the biofilm-embedded bacteria was determined by bioluminescence quantification. Using a mouse model of thermal burn infected with USA300 LAClux, we further assessed the effectiveness of aBL for treating localized infections. Bioluminescence imaging was performed to monitor in real time bacterial viability in vivo. Results: In vitro study showed that, for the planktonic counterpart of the bacteria or the 24-h-old biofilms, an irradiance of 55 mW/cm2 for 60 min resulted in a 4.61 log10 or 2.56 log10 inactivation, respectively. In vivo study using infected mouse burns demonstrated that a 2.56-log10 inactivation was achieved after 100-mW/cm2 irradiation for 62 min. Conclusions: aBL is a potential alternative approach for treating Methicillin-resistant Staphylococcus aureus infections.

Preventing Community-Associated Methicillin-Resistant "Staphylococcus aureus" among Student Athletes

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Many, Patricia S.

2008-01-01

Methicillin-resistant "Staphylococcus aureus" (MRSA) was once thought to be a bacterium causing infections in only hospitalized patients. However, a new strain of MRSA has emerged among healthy individuals who have not had any recent exposure to a hospital or to medical procedures. This new strain is known as "community-associated…

Next-Generation Sequence Analysis Reveals Transfer of Methicillin Resistance to a Methicillin-Susceptible Staphylococcus aureus Strain That Subsequently Caused a Methicillin-Resistant Staphylococcus aureus Outbreak: a Descriptive Study.

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Weterings, Veronica; Bosch, Thijs; Witteveen, Sandra; Landman, Fabian; Schouls, Leo; Kluytmans, Jan

2017-09-01

Resistance to methicillin in Staphylococcus aureus is caused primarily by the mecA gene, which is carried on a mobile genetic element, the staphylococcal cassette chromosome mec (SCC mec ). Horizontal transfer of this element is supposed to be an important factor in the emergence of new clones of methicillin-resistant Staphylococcus aureus (MRSA) but has been rarely observed in real time. In 2012, an outbreak occurred involving a health care worker (HCW) and three patients, all carrying a fusidic acid-resistant MRSA strain. The husband of the HCW was screened for MRSA carriage, but only a methicillin-susceptible S. aureus (MSSA) strain, which was also resistant to fusidic acid, was detected. Multiple-locus variable-number tandem-repeat analysis (MLVA) typing showed that both the MSSA and MRSA isolates were MT4053-MC0005. This finding led to the hypothesis that the MSSA strain acquired the SCC mec and subsequently caused an outbreak. To support this hypothesis, next-generation sequencing of the MSSA and MRSA isolates was performed. This study showed that the MSSA isolate clustered closely with the outbreak isolates based on whole-genome multilocus sequence typing and single-nucleotide polymorphism (SNP) analysis, with a genetic distance of 17 genes and 44 SNPs, respectively. Remarkably, there were relatively large differences in the mobile genetic elements in strains within and between individuals. The limited genetic distance between the MSSA and MRSA isolates in combination with a clear epidemiologic link supports the hypothesis that the MSSA isolate acquired a SCC mec and that the resulting MRSA strain caused an outbreak. Copyright © 2017 American Society for Microbiology.

Shortened Time to Identify Staphylococcus Species from Blood Cultures and Methicillin Resistance Testing Using CHROMAgar

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Shingo Chihara

2009-01-01

Full Text Available The ability to rapidly differentiate coagulase-negative staphylococcus (CoNS from Staphylococcus aureus and to determine methicillin resistance is important as it affects the decision to treat empiric antibiotic selection. The objective of this study was to evaluate CHROMagar S. aureus and CHROMagar MRSA (Becton Dickinson for rapid identification of Staphylococcus spp. directly from blood cultures. Consecutive blood culture bottles (BacT Alert 3D SA and SN, bioMérieux growing gram-positive cocci in clusters were evaluated. An aliquot was plated onto CHROMagar MRSA (C-MRSA and CHROMagar S. aureus (C-SA plates, which were read at 12 to 16 hours. C-SA correctly identified 147/147 S. aureus (100% sensitivity; 2 CoNS were misidentified as S. aureus (98% specificity. C-MRSA correctly identified 74/77 MRSA (96% sensitivity. None of the MSSA isolates grew on C-MRSA (100% specificity. In conclusion, CHROMagar is a rapid and sensitive method to distinguish MRSA, MSSA, and coagulase-negative Staphylococcus and may decrease time of reporting positive results.

Methicillin-resistant Staphylococcus aureus colonization and infection risks from companion animals: current perspectives

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Petinaki E

2015-11-01

Full Text Available Efthimia Petinaki,1 Iris Spiliopoulou21Department of Microbiology, School of Medicine, University of Thessalia, Larissa, 2Department of Microbiology, School of Medicine, University of Patras, Patras, GreeceAbstract: Methicillin-resistant Staphylococcus aureus (MRSA remains one of the most virulent human pathogens and has also recently been recognized as such in the veterinary settings. Companion animals, including dogs, cats, horses, small exotic animals, wildlife animals, and livestock, may constitute a reservoir for MRSA transmission to humans and vice versa. The evolution, emergence, and risk factors for MRSA transmission among colonized or infected animals are reviewed in the present paper, and infection control practices are discussed.Keywords: methicillin-resistant Staphylococcus aureus, companion animals, close contacts

Methicillin-Resistant Staphylococcus aureus Infections: A Comprehensive Review and a Plastic Surgeon's Approach to the Occult Sites.

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Hunter, Cedric; Rosenfield, Lorne; Silverstein, Elena; Petrou-Zeniou, Panayiota

2016-08-01

Up to 20 percent of the general population is persistently colonized with Staphylococcus aureus, and 1 to 3 percent of the population is colonized with community-acquired methicillin-resistant S. aureus. Currently, the knowledge of methicillin-resistant Staphylococcus aureus carriage sites other than the nose, and their effect on surgical site infections in cosmetic surgery, is lacking. A comprehensive literature review using the PubMed database to analyze prevalence, anatomical carrier sites, current screening and decontamination protocols and guidelines, and methicillin-resistant S. aureus in cosmetic surgery was performed. The senior author's (L.R.) methicillin-resistant S. aureus infection experience and prevention protocols were also reviewed. Nasal swabs detect only 50.5 percent of methicillin-resistant S. aureus colonization, and broad screening has noted the presence of methicillin-resistant S. aureus in the ear canal and umbilicus. Decolonization protocols within the orthopedic and cardiothoracic surgery literature have reduced rates of methicillin-resistant S. aureus surgical-site infections. There are no decolonization guidelines for plastic surgeons. Since instituting their decolonization protocol, the authors have had no cases of methicillin-resistant S. aureus infection in nearly 1000 cosmetic surgery procedures. There are very limited, if any, Level I or II data regarding methicillin-resistant S. aureus screening and decolonization. As the sequelae of a surgical-site infection can be disastrous, expert opinions recommend that plastic surgeons vigorously address methicillin-resistant S. aureus colonization and infection. The authors have developed and recommend a simple decolonization protocol that includes treatment of the umbilicus, ear canal, and nares to limit surgical-site infection and improve surgical outcomes.

Low methicillin-resistant Staphylococcus aureus carriage rate among Italian dental students

NARCIS (Netherlands)

Petti, S.; Kakisina, N.; Volgenant, C.M.C.; Messano, G.A.; Barbato, E.; Passariello, C.; de Soet, J.J.

2015-01-01

We assessed methicillin-resistant Staphylococcus aureus (MRSA) carriage rate among dental students from an Italian university. A total of 157 subjects participated (67 preclinical students and 90 clinical students); samples were collected from the nose, mouth, and skin. Five preclinical students and

Use of a primary isolation medium for recovery of methicillin-resistant Staphylococcus aureus.

OpenAIRE

Van Enk, R A; Thompson, K D

1992-01-01

Clinical specimens frequently contain methicillin-resistant Staphylococcus aureus (MRSA) isolates in low numbers or mixed with methicillin-susceptible staphylococci, which can obscure MRSA on nonselective media. By using an oxacillin-containing mannitol-salt-based selective and differential medium on 936 respiratory specimens, we recovered 45% more MRSA isolates (29 versus 20) than on nonselective media alone.

Characterization of methicillin-resistant Staphylococcus aureus isolates from pig carcasses in Hong Kong

DEFF Research Database (Denmark)

Ho, J.; O'Donoghue, M.; Guardabassi, Luca

2012-01-01

This study describes the isolation and characterization of methicillin-resistant Staphylococcus aureus (MRSA) from slaughtered pigs sampled from local markets in Hong Kong. The nares of 400 slaughtered pigs were cultured and MRSA isolates characterized for the presence of antibiotic-resistance de......This study describes the isolation and characterization of methicillin-resistant Staphylococcus aureus (MRSA) from slaughtered pigs sampled from local markets in Hong Kong. The nares of 400 slaughtered pigs were cultured and MRSA isolates characterized for the presence of antibiotic...... tet(M). Resistance to erythromycin (89%) and chloramphenicol (71%) was associated with the presence of erm(C), and fex(A), respectively. No strains carried cfr and there was no resistance to linezolid, although minimum inhibitory concentration (MICs) were close to the resistance break point...

Risk Factors for Nosocomial Bacterremia Due to Methicillin-Resistant Staphylococcus Aureus

NARCIS (Netherlands)

M. Pujol (Miquel); C. Pena; R. Pallares (Roman); J. Ayats (Josefina); J. Ariza (Javier); F. Gudiol (Francesc)

1994-01-01

textabstractIn a prospective surveillance study (February 1990–December 1991) performed at a 1000-bed teaching hospital to identify risk factors for nosocomial methicillin-resistantStaphylococcus aureus (MRSA) bacteremia, 309 patients were found to be colonized (n=103; 33 %) or infected (n=206; 67

SDS-PAGE and gel IEF – tool for differentiation of methicillin-resistant and methicillin-sensitive strains of Staphylococcus aureus

Czech Academy of Sciences Publication Activity Database

Tesařová, Marie; Horká, Marie; Moravcová, Dana; Svojanovská, Lenka; Mlynariková, K.; Růžička, F.

2016-01-01

Roč. 72, č. 3 (2016), s. 315-320 ISSN 0343-8651 R&D Projects: GA MV VG20112015021 Institutional support: RVO:68081715 Keywords : methicillin-resistant and methicillin-sensitive Staphylococcus aureus * sodium dodecylsulphate polyacrylamide gel electrophoresis * gel isoelectric focusing * precipitated proteins Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 1.322, year: 2016 http://hdl.handle.net/11104/0251069

Effectiveness of simple control measures on methicillin-resistant Staphylococcus aureus infection status and characteristics with susceptibility patterns in a teaching hospital in Peshawar.

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Rafiq, Muhammad Salman; Rafiq, Muhammad Imran; Khan, Taimur; Rafiq, Maria; Khan, Mah Muneer

2015-09-01

To determine the effectiveness of simple control measures on the infection status and characteristics of methicillin-resistant Staphylococcus aureus including susceptibility patterns among health professionals and patients in a teaching hospital. The cross-sectional study was conducted from September 2013 to January 2014, and comprised samples collected from healthcare personnel and patients in the various units of Khyber Teaching Hospital, Peshawar. The specimens were collected before and one month after the implementation of simple control measures for outbreak prevention of methicillin-resistant Staphylococcus aureus. These were tested for culture and antimicrobial susceptibility. Data about methicillin-sensitive and methicillin-resistant Staphylococcus aureus infection, wound characteristics and susceptibility patterns was collected and effectiveness of simple control measures was determined. SPSS 20 was used for statistical analysis. Of the total 390 isolates, 180(46.2%) were Staphylococcus aureus; 77(19.7%) from healthcare personnel and 103(26.4%) from patients. Of these, 164(42.1%) were methicillin-sensitive and 16(4.1%) were methicillin-resistant. Among the patients, 38(15.1%) methicillin-sensitive and 8(3.2%) methicillin-resistant isolates were recovered from wounds or skin and soft tissues. Pus with 33(13.1%) and 4(1.6%) cases respectively was the second most common source. Among methicillin-resistant isolates, resistance to Linezolid was 0%, all were resistant to Oxacillin, Cefoxitin, Amoxicillin, Cefotaxime and Cephradine, and resistance to both Co-Amoxiclav and Ciprofloxacin was 87.5%. After one month of implementation of simple control measures, the number of methicillin-resistant cases among healthcare professionals and patients dropped from 4(2.9%) and 7(10.8%) to 1(0.7%) and 5(2.7%), respectively. Methicillin-resistant and methicillin-sensitive Staphylococcus aureus differed in their anti-microbial susceptibility profiles. Selection of antibiotics

Fitness and competitive growth comparison of methicillin resistant and methicillin susceptible Staphylococcus aureus colonies.

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Durhan, Emine; Korcan, Safiye Elif; Altindis, Mustafa; Konuk, Muhsin

2017-05-01

Exponential developments of both Methicillin resistant Staphylococcus aureus (MRSA) 3R ve 36R and methicillin susceptible Staphylococcus aureus (MSSA) 27S were evaluated in the presence and absence of oxacillin. The strains were isolated from the specimens collected in microbiology department. It was also determined the transfer of mecA gene from 3R to 27S strain by using the replica plate technique. It was observed that the presence of antibiotics in the preliminary culture had a positive impact on the growth of the secondary culture of MRSA isolates. Comparison results of Rt bacteria in three different mixed cultures, assessed with Tukey's HSD test, showed a significant statistical difference among the groups. The values were as following; on the first day; Df: 2, F: 60.90, P: 0.0001, second day; Df:2, F:90.56, P: 0.0000, and third day; Df:2, F:4.86, P:0.0557. As a result of the study, we can suggest that the gene expression levels of the transferred antibiotic resistance genes could help us in both controlling hospital originated sickness and developing new strategies to prevent the spread of resistant bacteria. Copyright © 2016 Elsevier Ltd. All rights reserved.

Heavy metal and disinfectant resistance genes among livestock-associated methicillin-resistant Staphylococcus aureus isolates

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Argudin, Maria Angeles; Lauzat, Birgit; Kraushaar, Britta

2016-01-01

Livestock associated methicillin-resistant Staphylococcus aureus (LA-MRSA) has emerged in animal production worldwide. Most LA-MRSA in Europe belong to the clonal complex (CC)398. The reason for the LA-MRSA emergence is not fully understood. Besides antimicrobial agents used for therapy, other su...

Methicillin-resistant Staphylococcus aureus screening as a patient safety initiative: using patients' experiences to improve the quality of screening practices.

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Currie, Kay; Knussen, Christina; Price, Lesley; Reilly, Jacqui

2014-01-01

To explore the patient experience and acceptability of methicillin-resistant Staphylococcus aureus screening of inpatient admissions to acute hospital settings. Prevention of healthcare-associated infections such as methicillin-resistant Staphylococcus aureus is a major patient safety concern internationally. Screening of patients for methicillin-resistant Staphylococcus aureus colonisation is becoming a routine aspect of hospital admission; however, evidence of the patient experience and acceptability of methicillin-resistant Staphylococcus aureus screening is limited. A mixed-methods study set in six acute care hospitals in three Scottish regions. Data collection involved postdischarge self-report survey of patients who had been screened (n = 54) and qualitative patient interviews (n = 10). Theoretical constructs derived from the Health Belief Model and Theory of Planned Behaviour used in analysis. Findings indicated that methicillin-resistant Staphylococcus aureus screening was broadly acceptable to patients. The experience of screening did not appear to be problematic; responses demonstrate that screening provided reassurance and generated confidence that health organisations were tackling healthcare-associated infections. Patients were less positive regarding the provision of information, the possibility of refusing a screen and the consequences of a positive test result. Furthermore, there were indications that patients wanted to be told the results of the screen and strong support for screening of hospital staff. Analysis of constructs from our theoretical frameworks provides evidence that attitudes were largely positive; responses indicate a belief in the beneficial impact of methicillin-resistant Staphylococcus aureus screening for patients and the wider community. However, it is important that health professionals continually assess the patient experience of 'routine' aspects of health care such as MRSA screening. The findings from this study suggest that

Nasal and hand carriage rate of methicillin resistant Staphylococcus aureus (MRSA) among health care workers in Mekelle Hospital, North Ethiopia.

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Gebreyesus, Araya; Gebre-Selassie, Solomon; Mihert, Adane

2013-01-01

Methicillin resistant Staphylococcus aureus (MRSA) is significant major pathogen responsible for hospital and community based infections. The aim of this study was to assess the nasal and hand carriage of methicillin resistant Staphylococcus aureus in health care workers of Mekelle Hospital The study was carried out during November 2010 to January 2011. Swab samples from both anterior nares and hands were taken. The samples were cultured on mannitol salt agar and incubated aerobically at 37 degrees C for 48 hours. Staphylococcus aureus was identified as nmannitol fermenter and coagulase test positive. Antimicrobial susceptibility test for MRSA was done by disk diffusion method using oxacillin disks. Data were analysed using SPSS version 16 software. Out of the 177 health care workers screened, 36 (20.3%) of them were methicillin resistant Staphylococcus aureus carriers in their hand and anterior nares. More females, 25(14.1%) were colonized by methicillin resistant Staphylococcus aureus than males 11 (6.2%) (P = 0.044). Nasal carriage of MRSA of 25 (14.1%) was higher than hand carriage 11 (6.2%) (p resistant Staphylococcus aureus carriage rates of 26 (13.6%) and 4 (2.3%), respectively. The isolated MRSA were resistant to multiple antibiotics. The highest resistance was observed for ampicillin (88.9%) and tetracycline (86.1%). Two (5.6%) of the nasal isolates were vancomycin resistant. Methicillin resistant Staphylococcus aureus carriage among health care workers in this study was high. The carriage rate was higher among nurses and doctors. The MRSA isolates were multi drug resistant to other antibiotics. So, the result of this study emphasizes the need of regular surveillance of health care workers. It also calls a need for an effective infection prevention and control program.

Heterogeneity among methicillin-resistant Staphylococcus aureus from Italian pig finishing holdings

DEFF Research Database (Denmark)

Battisti, A.; Franco, A.; Merialdi, G.

2010-01-01

A survey for methicillin-resistant Staphylococcus aureus (MRSA) in finishing pig holdings was carried out in Italy in 2008. MRSA isolates were characterised by spa-. SCCmec- and antimicrobial susceptibility typing. A prevalence of 38% (45/118, 95% CI 29.4-46.9%) positive holdings was observed...

Emergence of methicillin-resistant Staphylococcus aureus (MRSA) in different animal species

NARCIS (Netherlands)

Cuny, Christiane; Friedrich, Alexander; Kozytska, Svetlana; Layer, Franziska; Nübel, Ulrich; Ohlsen, Knut; Strommenger, Birgit; Walther, Birgit; Wieler, Lothar; Witte, Wolfgang

The emergence of methicillin-resistant Staphylococcus aureus (MRSA) in animals such as horses, pet animals and productive livestock has raised questions of a probable human origin and in more general of host specificity of S. aureus. Particular clonal lineages are obviously specific for humans (e.g.

Dissemination of antibiotic resistance in methicillin-resistant Staphylococcus aureus and vancomycin-resistant S aureus strains isolated from hospital effluents.

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Mandal, Santi M; Ghosh, Ananta K; Pati, Bikas R

2015-12-01

Vancomycin-resistant Staphylococcus aureus (VRSA) and methicillin-resistant S aureus (MRSA) strains were examined in hospital effluents. Most S aureus strains are resistant to methicillin (MRSA), followed by tetracycline. Approximately 15% of MRSA strains are also resistant to vancomycin (VRSA). All VRSA strains developed a VanR/VanS-regulated 2-component system of VanA-type resistance in their genome. Results indicate that there is a possibility of developing resistance to aminoglycosides by VRSA strains in the near future. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Co-infection of methicillin-resistant Staphylococcus epidermidis, methicillin-resistant Staphylococcus aureus and extended spectrum β-lactamase producing Escherichia coli in bovine mastitis--three cases reported from India.

Science.gov (United States)

Bandyopadhyay, Samiran; Samanta, Indranil; Bhattacharyya, Debaraj; Nanda, Pramod Kumar; Kar, Debasish; Chowdhury, Jayanta; Dandapat, Premanshu; Das, Arun Kumar; Batul, Nayan; Mondal, Bimalendu; Dutta, Tapan Kumar; Das, Gunjan; Das, Bikash Chandra; Naskar, Syamal; Bandyopadhyay, Uttam Kumar; Das, Suresh Chandra; Bandyopadhyay, Subhasish

2015-03-01

Emergence of antimicrobial resistance among bovine mastitis pathogens is the major cause of frequent therapeutic failure and a cause of concern for veterinary practitioners. This study describes intra-mammary infection of methicillin-resistant Staphylococcus epidermidis (MRSE), methicillin-resistant Staphylococcus aureus (MRSA) and extended spectrum β-lactamase (ESBL) producing Escherichia coli in two Holstein Friesian crossbred cows with subclinical mastitis and one non-descript cow with clinical mastitis in two different districts of West Bengal, India. In total, three MRSE, one MRSA and three ESBL producing E. coli were isolated from these cases. Both the crossbreds were detected with MRSE (HFSE1 and HFSE2) and ESBL producing E. coli (HFEC1 and HFEC2), whereas, simultaneous infection of three pathogens viz. MRSA (NDSA1), MRSE (NDSE1) and ESBL producing E. coli (NDEC1) was found in the non-descript cow. The methicillin-resistant isolates possessed mecA gene and exhibited resistance to various antibiotics such as amikacin, tetracycline and glycopeptides. The ESBL producers were positive for blaCTX-M and blaTEM genes; in addition, HFEC1 and HFEC2 were positive for blaSHV and possessed the genes for class I integron (int1), sulphonamide resistance (sul1), quinolone resistance (qnrS) and other virulence factors (papC, iucD and ESTA1). All the ESBL producers exhibited resistance to a variety of antibiotics tested including third- and fourth-generation cephalosporins and were also intermediately resistant to carbapenems. This is the first ever report on simultaneous occurrence of MRSE, MRSA and ESBL producing E. coli in bovine mastitis indicating a major concern for dairy industry and public health as well.

Characterization and lytic activity of methicillin-resistant Staphylococcus aureus(MRSA phages isolated from NICU

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Golnar Rahimzadeh

2016-06-01

Full Text Available Background Methicillin-resistant Staphylococcus aureus (MRSA is a well-known pathogen that causes serious diseases in humans. As part of the efforts to control this pathogen, an isolated bacteriophage, Siphoviridae, which specifically targets Methicillin-resistant Staphylococcus aureus (MRSA, was characterized. Aims The objective of this study was to characterize of a virulent bacteriophage (Siphoviridae isolated from a NICU bathroom sink. Methods The MRSA strain was isolated from patient blood. The isolated strain was confirmed as MRSA using conventional methods. Phages were isolated from a NICU bathroom sink and activity was lytic as determined by spot test. Titer phage lysate was measured by the Double Layer Agar (DLA technique. The morphology was found with electron microscopy. The single-step growth curve was plotted. Results Electron microscopy showed the phage as a member of the family Siphoviridae, serogroup A and F. The isolated phage was capable of lytic activity against methicillin-resistant Staphylococcus aureus (MRSA strain as shown by spot test. By DLA, the titre of the phages was determined to be 10×108PFU/ml. The single-step growth curve showed that the latent period of the isolated bacteriophage was 30 min and the total number of viable progeny per infected host, burst size, was 2600 PFU/infected host. Conclusion In this study, two phages were isolated and characterized from a NICU bathroom sink, from the Siphoviridae family, which specifically targetsmethicillin-resistant Staphylococcus aureus (MRSA.

Methicillin-resistant Staphylococcus aureus prevalence: Current susceptibility patterns in Trinidad

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Land Michael

2006-05-01

Full Text Available Abstract Background Methicillin-resistant Staphylococcus aureus (MRSA has become one of the most widespread causes of nosocomial infections worldwide. Recently, reports have emerged that S. aureus strains recovered from community-acquired infections are also methicillin-resistant. This study was undertaken to analyze the prevalence of methicillin resistance among isolates at a regional hospital in Trinidad, and document the current resistance profile of MRSA and methicillin-sensitive Staphylococcus aureus (MSSA to the commonly used anti-staphylococcal agents. Methods Over a 6-year period we analyzed 2430 isolates of S. aureus strains recovered from various clinical sources, from hospital and community practices. Antimicrobial susceptibility testing was done according to guideline recommendations of the National Committee for Clinical Laboratory Standards. Results The prevalence of MRSA from surgical/burn wounds, urine and pus/abscess were 60.1%, 15.5% and 6.6%, respectively. The major sources of MSSA were surgical/burn wounds, pus/abscess and upper respiratory tract specimens with rates of 32.9%, 17.1% and 14.3%, respectively. The greatest prevalence of resistance of MRSA was seen for erythromycin (86.7%, and clindamycin (75.3%. Resistance rates among MSSA were highest for ampicillin (70%. Resistance rates for tetracycline were similar among both MRSA (78.7% and MSSA (73.5%. The MRSA recovery rates from nosocomial sources (20.8% was significantly higher than that of previous years (12.5% (p Conclusion The prevalence of MRSA in the hospital increased from 12.5% in 1999 to 20.8% in 2004. Most isolates were associated with infected surgical/burn wounds which may have become infected via the hands of HCPs during dressing exercises. Infection control measures aimed at the proper hand hygiene procedures may interrupt the spread of MRSA. HCPs may also be carriers of MRSA in their anterior nares. Surveillance cultures of both patients and HCPs may help

Frequency and Treatment of Methicillin Resistant Staphylococcus aureus in Obstetric and Gynaecological Sepsis

International Nuclear Information System (INIS)

Butt, I.J.; Khan, S.; Bhutta, S.; Butt, S.

2013-01-01

Objective: To perform culture and sensitivity for pathogens causing puerperal and postoperative wound sepsis and determine the frequency of Methicillin Resistant Staphylococcus aureus (MRSA) in such infections. Study Design: Observational study. Place and Duration of Study: Obstetrics and Gynaecology Ward, Jinnah Postgraduate Medical Centre, Karachi, from December 2008 to May 2010. Methodology: All patients presenting with puerperal sepsis or postoperative wound infection were enrolled. Pus was collected for culture and sensitivity using standard technique. Two samples were taken from each patient; one before starting the treatment and one at the end of treatment. Ames transport medium was used. Empirical treatment with triple regimen (Ampicillin, Metronidazole and Gentamicin) was started immediately to cover Gram positive as well as negative bacteria in addition to anaerobic infection. After receiving the sensitivity report, antimicrobial agent were changed accordingly. Samples from ward and theater staff and environment were also taken to look for possible mode of transmission. Data was recorded on a proforma. Discrete variables are expressed as percentages. Results: Staphylococcus aureus was the most frequent organism isolated in 34.6% cases. Methicillin sensitive Staphylococcus aureus was seen in 20% cases and methicillin resistant Staphylococcus aureus was seen in 14.6%. Out of these 14.6% MRSA, (17) 77% was associated with puerperal sepsis and rest (5) 23% was associated with postoperative wound infection. It showed best sensitivity to vancomycin. Conclusion: Staphylococcus aureus and E. coli were common causative agent of postoperative infections and puerperal sepsis. (author)

Response of Methicillin-Resistant Staphylococcus aureus to Amicoumacin A

OpenAIRE

Lama, Amrita; Pané-Farré, Jan; Chon, Tai; Wiersma, Anna M.; Sit, Clarissa S.; Vederas, John C.; Hecker, Michael; Nakano, Michiko M.

2012-01-01

Amicoumacin A exhibits strong antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA), hence we sought to uncover its mechanism of action. Genome-wide transcriptome analysis of S. aureus COL in response to amicoumacin A showed alteration in transcription of genes specifying several cellular processes including cell envelope turnover, cross-membrane transport, virulence, metabolism, and general stress response. The most highly induced gene was lrgA, encoding an antiho...

Comparative molecular analysis substantiates zoonotic potential of equine methicillin-resistant Staphylococcus aureus

NARCIS (Netherlands)

Walther, Birgit; Monecke, Stefan; Ruscher, Claudia; Friedrich, Alexander W; Ehricht, Ralf; Slickers, Peter; Soba, Alexandra; Wleklinski, Claus-G; Wieler, Lothar H; Lübke-Becker, Antina

Despite the increasing importance of methicillin-resistant Staphylococcus aureus (MRSA) in veterinary medicine, knowledge about the epidemiology of the pathogen in horses is still poor. The phylogenetic relationship of strains of human and equine origins has been addressed before, usually by

Nosocomial transmission of community-associated methicillin-resistant Staphylococcus aureus in Danish Hospitals

NARCIS (Netherlands)

Hetem, D.J.; Westh, H.; Boye, K.; Jarlov, J.O.; Bonten, M.J.M.; Bootsma, M.C.J.

2012-01-01

Objectives The emergence of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has changed the epidemiology of MRSA infections worldwide. In contrast to hospital-associated MRSA (HA-MRSA), CA-MRSA more frequently affects healthy individuals, both with and without recent

Antibiotics for methicillin-resistant Staphylococcus aureus skin and soft tissue infections: the challenge of outpatient therapy.

Science.gov (United States)

Pate, Amy J; Terribilini, Reno Giovonni; Ghobadi, Farzaneh; Azhir, Alaleh; Barber, Andre; Pearson, Julie Marie; Kalantari, Hossein; Hassen, Getaw W

2014-02-01

Methicillin-resistant Staphylococcus aureus (MRSA) infections are becoming increasingly prevalent in both community and hospital settings. Certain strains are notorious for causing skin and soft tissue infections in patients with no established risk factors. In this article, we report our findings on the dynamic antibiotic resistance pattern of MRSA and outpatient prescription trend for skin and soft tissue infections within our community. We conducted a retrospective medical record review of 1876 patients evaluated in the emergency department of an urban community hospital from 2003 to 2012. Data regarding culture isolates and associated antimicrobial resistance, antibiotic treatment, site of specimen collection, age, race, and sex were collected and analyzed. Analysis of 1879 culture specimens yielded 2193 isolates. In some cases, a single specimen yielded polymicrobial growth. Staphylococcus aureus represented 996 isolates (45.4%); 463 were methicillin-susceptible (21.1%) and 533 (24.3%) were methicillin-resistant. Most patients were prescribed a single- or poly-drug regimen of trimethoprim/sulfamethoxazole, cephalexin, and clindamycin. Antimicrobial resistance analysis indicated that MRSA became increasingly resistant to the aforementioned antibiotics over time: 10% and 6% in 2012 vs 3.5% and 3.4% in 2007 for clindamycin and trimethoprim/sulfamethoxazole, respectively. Methicillin-resistant Staphylococcus aureus is a particularly virulent, rapidly adaptive pathogen that is becoming increasingly difficult to combat with existing antibiotics. Care must be taken to ensure appropriate treatment and follow-up of patients with known MRSA infections. © 2013.

Effectiveness of a Glycylcycline Antibiotic for Reducing the Pathogenicity of Superantigen-Producing Methicillin-Resistant Staphylococcus aureus in Burn Wounds.

Science.gov (United States)

Nosanov, Lauren B; Jo, Daniel Y; Randad, Pranay R; Moffatt, Lauren T; Carney, Bonnie C; Ortiz, Rachel T; Shupp, Jeffrey W

2017-01-01

Objective : Burn-injured patients are highly susceptible to infectious complications, which are often associated with increased morbidity and mortality. Rates of antibiotic resistance have increased, and resistant species such as methicillin-resistant Staphylococcus aureus provide additional challenges in the form of virulence factors. Proteins can disrupt local healing, leading to systemic immune disruption. To optimize outcomes, treatments that reduce pathogenicity must be identified. This study aims to compare a glycylcycline antibiotic-tigecycline-with clindamycin for effectiveness in treating superantigenic methicillin-resistant Staphylococcus aureus in burn wounds. Methods : Sprague-Dawley rats received paired 2 × 2-cm burn wounds, which were subsequently inoculated with known virulence factor-producing methicillin-resistant Staphylococcus aureus or media alone on postinjury day 1. Infected animals received twice-daily tigecycline (high or low dose), twice-daily clindamycin (high or low dose), or saline alone (positive controls). Daily sampling and imaging assessments were performed. Results : Bacterial counts and toxin levels were reduced significantly in antibiotic-treated groups relative to positive controls ( P study supports the use of tigecycline in the treatment of methicillin-resistant Staphylococcus aureus -infected burn wounds. While both protein synthesis inhibitors are effective, tigecycline appears to be superior in controlling toxin levels, enabling better wound healing.

Diabetes and early postpartum methicillin-resistant Staphylococcus aureus infection in US hospitals

NARCIS (Netherlands)

Parriott, Andrea M.; Arah, Onyebuchi A.

2013-01-01

The epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) infection in postpartum women is not well characterized. Because diabetes is a risk factor for some infections, we sought to characterize the relationship between diabetes and invasive MRSA infections in women admitted to US

Emergence of Livestock-Associated Methicillin-Resistant Staphylococcus aureus Bloodstream Infections in Denmark

DEFF Research Database (Denmark)

Larsen, Jesper; Petersen, Andreas; Larsen, Anders R.

2017-01-01

Background: Livestock-associated methicillin-resistant Staphylococcus aureus clonal complex 398 (LA-MRSA CC398) is causing an increasing number of skin and soft tissue infections (SSTIs) in Denmark and other European countries with industrial pig production. Yet, its impact on MRSA bloodstream...

Cross-border dissemination of methicillin-resistant Staphylococcus aureus, Euregio Meuse-Rhin region

NARCIS (Netherlands)

Deurenberg, Ruud H; Nulens, Eric; Valvatne, Havard; Sebastian, Silvie; Driessen, Christel; Craeghs, Jos; De Brauwer, Els; Heising, Bernhard; Kraat, Yvette J; Riebe, Joachim; Stals, Frans S; Trienekens, Thera A; Scheres, Jacques; Friedrich, Alexander W; van Tiel, Frank H; Beisser, Patrick S; Stobberingh, Ellen E

Because the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) differs among the 3 countries forming the Euregio Meuse-Rhin (EMR) region (Belgium, Germany, and the Netherlands), cross-border healthcare requires information about the spread of MRSA in the EMR. We investigated the

Evaluation of Ceftobiprole in a Rabbit Model of Aortic Valve Endocarditis Due to Methicillin-Resistant and Vancomycin-Intermediate Staphylococcus aureus

OpenAIRE

Chambers, Henry F.

2005-01-01

Ceftobiprole is a novel broad-spectrum cephalosporin that binds with high affinity to PBP 2a, the methicillin-resistance determinant of staphylococci, and is active against methicillin- and vancomycin-resistant Staphylococcus aureus. Ceftobiprole was compared to vancomycin in a rabbit model of methicillin-resistant S. aureus aortic valve endocarditis. Ceftobiprole and vancomycin were equally effective against endocarditis caused by methicillin-resistant S. aureus strain 76, whereas ceftobipro...

PARTIAL CHARACTERIZATION OF A LYTIC METHICILLIN RESISTANT-STAPHYLOCOCCUS AUREUS BACTERIOPHAGE

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Sulaiman Al-Yousef

2014-12-01

Full Text Available A marked increase in the infection incidence caused by methicillin-resistant Staphylococcus aureus (MRSA strains has been noted in medical practice in recent years. This study was conducted to study the biological and characterize of MRSA-phage. Methicillin resistance of Staphylococcus aureus was detected and confirmed by determining of the MIC of oxacillin by the standard agar dilution method. Phage was biologically purified using single plaque technique, then phage characterization were studied using host range, adsorption time, particle morphology and its structural protein. MRSA phage showing lytic nature was purified by repeated plating after picking of single isolated plaques. This phage is active against all 11 isolates either of S. aureus or MRSA tested as hosts. Phage produced clear plaques indicating their lytic nature. This phage was concentrated employing polyethylene glycol (PEG-NaCl precipitation method. Morphologically, MRSA Phage has a hexagonal head having a long non-contractile tail, indicating his icosahedral nature. Adsorption studies showed 100% adsorption of MRSA-Phage after 35 minutes of exposure. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE experimentation indicated that the phage particles contain one major structural protein (about 30 Kda.

Occurrence of methicillin-resistant Staphylococci in surgically treated dogs and the environment in a Swedish animal hospital.

Science.gov (United States)

Bergström, A; Gustafsson, C; Leander, M; Fredriksson, M; Grönlund, U; Trowald-Wigh, G

2012-07-01

To investigate whether hospitalised dogs treated surgically may become culture positive for methicillin-resistant Staphylococcus pseudintermedius or methicillin-resistant Staphylococcus aureus. Surgically treated dogs (n=45) were sampled for methicillin-resistant Staphylococcus pseudintermedius or methicillin-resistant Staphylococcus aureus on admission, before and after surgery and at the time of removal of surgical stitches. The hospital environment (n=57), including healthy dogs in the veterinary hospital environment (n=34), were sampled for methicillin-resistant Staphylococcus pseudintermedius or methicillin-resistant Staphylococcus aureus. Genetic variations among methicillin-resistant Staphylococcus pseudintermedius or methicillin-resistant Staphylococcus aureus isolates were identified through detection of restriction fragment polymorphisms. No dogs developed a wound infection due to methicillin-resistant Staphylococcus pseudintermedius or methicillin-resistant Staphylococcus aureus. However, there was a significant increase in the number of dogs carrying methicillin-resistant Staphylococcus pseudintermedius after hospitalisation compared to admission (Ppresent in the environment. Methicillin-resistant Staphylococcus pseudintermedius isolates were recovered from environmental surfaces and hospitalised animals, but not from healthy dogs. Methicillin-resistant Staphylococcus pseudintermedius isolates representing nine different restriction endonuclease digestion patterns were found, with two of these occurring in both the environment and on dogs. Dogs may contract methicillin-resistant Staphylococcus pseudintermedius in association with surgery and hospitalisation. Resistant bacteria may be transmitted between dogs, staff and the environment. Dogs colonised with methicillin-resistant Staphylococcus pseudintermedius may be a source for hospital- and community-acquired infections. © 2012 British Small Animal Veterinary Association.

Prevalence of methicillin-resistant Staphylococcus aureus (MRSA in community-acquired primary pyoderma

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Patil Rahul

2006-01-01

Full Text Available Background: Although prevalence of MRSA strains is reported to be increasing, there are no studies of their prevalence in community-acquired primary pyodermas in western India. Aims: This study aimed at determining the prevalence of MRSA infection in community-acquired primary pyodermas. Methods: Open, prospective survey carried out in a tertiary care hospital in Mumbai. Materials and Methods: Eighty-six patients with primary pyoderma, visiting the dermatology outpatient, were studied clinically and microbiologically. Sensitivity testing was done for vancomycin, sisomycin, gentamicin, framycetin, erythromycin, methicillin, cefazolin, cefuroxime, penicillin G and ciprofloxacin. Phage typing was done for MRSA positive strains. Results : The culture positivity rate was 83.7%. Staphylococcus aureus was isolated in all cases except two. Barring one, all strains of Staphylococcus were sensitive to methicillin. Conclusions: Methicillin resistance is uncommon in community-acquired primary pyodermas in Mumbai. Treatment with antibacterials active against MRSA is probably unwarranted for community-acquired primary pyodermas.

Identification of methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from burn patients by multiplex PCR.

Science.gov (United States)

Montazeri, Effat Abbasi; Khosravi, Azar Dokht; Jolodar, Abbas; Ghaderpanah, Mozhgan; Azarpira, Samireh

2015-05-01

Methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative staphylococci (MRCoNS) as important human pathogens are causes of nosocomial infections worldwide. Burn patients are at a higher risk of local and systemic infections with these microorganisms. A screening method for MRSA by using a multiplex polymerase chain reaction (PCR) targeting the 16S ribosomal RNA (rRNA), mecA, and nuc genes was developed. The aim of the present study was to investigate the potential of this PCR assay for the detection of MRSA strains in samples from burn patients. During an 11-month period, 230 isolates (53.11%) of Staphylococcus spp. were collected from burn patients. The isolates were identified as S. aureus by using standard culture and biochemical tests. DNA was extracted from bacterial colonies and multiplex PCR was used to detect MRSA and MRCoNS strains. Of the staphylococci isolates, 149 (64.9%) were identified as S. aureus and 81 (35.21%) were described as CoNS. Among the latter, 51 (62.97%) were reported to be MRCoNS. From the total S. aureus isolates, 132 (88.6%) were detected as MRSA and 17 (11.4%) were methicillin-susceptible S. aureus (MSSA). The presence of the mecA gene in all isolates was confirmed by using multiplex PCR as a gold standard method. This study presented a high MRSA rate in the region under investigation. The 16S rRNA-mecA-nuc multiplex PCR is a good tool for the rapid characterization of MRSA strains. This paper emphasizes the need for preventive measures and choosing effective antimicrobials against MRSA and MRCoNS infections in the burn units. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

Occurrence and molecular characteristics of methicillin-resistant Staphylococcus aureus and methicillin-resistant Staphylococcus pseudintermedius in an academic veterinary hospital.

Science.gov (United States)

Ishihara, Kanako; Shimokubo, Natsumi; Sakagami, Akie; Ueno, Hiroshi; Muramatsu, Yasukazu; Kadosawa, Tsuyoshi; Yanagisawa, Chie; Hanaki, Hideaki; Nakajima, Chie; Suzuki, Yasuhiko; Tamura, Yutaka

2010-08-01

Recently, methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus pseudintermedius (MRSP) have been increasingly isolated from veterinarians and companion animals. With a view to preventing the spread of MRSA and MRSP, we evaluated the occurrence and molecular characteristics of each in a veterinary college. MRSA and MRSP were isolated from nasal samples from veterinarians, staff members, and veterinary students affiliated with a veterinary hospital. Using stepwise logistic regression, we identified two factors associated with MRSA carriage: (i) contact with an identified animal MRSA case (odds ratio [OR], 6.9; 95% confidence interval [95% CI], 2.2 to 21.6) and (ii) being an employee (OR, 6.2; 95% CI, 2.0 to 19.4). The majority of MRSA isolates obtained from individuals affiliated with the veterinary hospital and dog patients harbored spa type t002 and a type II staphylococcal cassette chromosome mec (SCCmec), similar to the hospital-acquired MRSA isolates in Japan. MRSA isolates harboring spa type t008 and a type IV SCCmec were obtained from one veterinarian on three different sampling occasions and also from dog patients. MRSA carriers can also be a source of MRSA infection in animals. The majority of MRSP isolates (85.2%) carried hybrid SCCmec type II-III, and almost all the remaining MRSP isolates (11.1%) carried SCCmec type V. MRSA and MRSP were also isolated from environmental samples collected from the veterinary hospital (5.1% and 6.4%, respectively). The application of certain disinfection procedures is important for the prevention of nosocomial infection, and MRSA and MRSP infection control strategies should be adopted in veterinary medical practice.

Food-initiated outbreak of methicillin-resistant Staphylococcus aureus analyzed by pheno- and genotyping

NARCIS (Netherlands)

J.A.J.W. Kluytmans (Jan); R. Hollis; S. Messer; L. Herwaldt; J. Bruining (Hans); M. Heck; J. Rost; N. van Leeuwen; W.H.F. Goessens (Wil); W.B. van Leeuwen (Willem)

1995-01-01

textabstractAn outbreak of methicillin-resistant Staphylococcus aureus (MRSA) involving 27 patients and 14 health-care workers (HCW) was studied. The outbreak started in the hematology unit of the University Hospital Rotterdam, Dijkzigt, The Netherlands, and spread to

Screening of nasal carriage of methicillin-resistant Staphylococcus aureus during admission of patients to Frantz Fanon Hospital, Blida, Algeria

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Mohamed Amine Ouidri

2018-05-01

Full Text Available A study was performed of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA strains isolated from nasal preoperative samples. Of 663 samples assessed, staphylococcus was detected in 143 (21.57%. The disc diffusion method (cefoxitin 30 μg, a screening test (oxacillin 6 μg/mL and a search for Protein Binding Additional Penicillin 2 (PLP2a allowed the detection and confirmation of resistance to methicillin for 36 strains, a rate of 5.43% of the total population studied. Eight MRSA carriers received care in the trauma service, 14 in cardiology, five in ear, nose and throat, four in neurosurgery and paediatrics, and one in SCI. Thirty-six methicillin-resistant of the nasal portage strains are in their great majority, 27 of 36, rather limited multi-R character (two to three families namely resistance: tetracyclines, fluoroquinolones, aminoglycosides, macrolides. One of the MRSA strains was found to have intermediate sensitivity to vancomycin. Keywords: Antibiotic resistance, Healthy volunteers, MRSA, Prevalence, Staphylococcus aureus

Methicillin-Resistant Staphylococcus aureus ST398 from Human Patients, Upper Austria

Science.gov (United States)

Metz-Gercek, Sigrid; Mittermayer, Helmut

2009-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) clonal type ST398 is usually associated with animals. We examined 1,098 confirmed MRSA samples from human patients and found that 21 were MRSA ST398. Most (16) patients were farmers. Increasing prevalence from 1.3% (2006) to 2.5% (2008) shows emergence of MRSA ST398 in humans in Austria. PMID:19402964

Methicillin-Resistant Staphylococcus aureus (MRSA) Detected at Four U.S. Wastewater Treatment Plants

OpenAIRE

Goldstein, Rachel E. Rosenberg; Micallef, Shirley A.; Gibbs, Shawn G.; Davis, Johnnie A.; He, Xin; George, Ashish; Kleinfelter, Lara M.; Schreiber, Nicole A.; Mukherjee, Sampa; Sapkota, Amir; Joseph, Sam W.; Sapkota, Amy R.

2012-01-01

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...

In vitro susceptibility of chloramphenicol against methicillin-resistant staphylococcus aureus

International Nuclear Information System (INIS)

Fayyaz, M.; Mirza, I.A.; Hussain, A.; Abbasi, S.A.; Ali, S.; Ahmed, Z.

2013-01-01

To determine the in vitro susceptibility of chloramphenicol against methicillin-resistant Staphylococcus aureus. Study Design: Cross-sectional study. Place and Duration of Study: Department of Microbiology, Armed Forces Institute of Pathology, Rawalpindi, from January to June 2012. Methodology: One hundred and seventy four isolates of methicillin-resistant Staphylococcus aureus were included in this study using cefoxitin (30 A g) disc for detection. Minimum inhibitory concentration (MIC) of chloramphenicol against MRSA was determined by using E-strip (AB BIO DISK). The susceptibility was determined by swabbing the Mueller-Hinton agar (MHA) plates with the resultant saline suspension of MRSA and applying E-strip of chloramphenicol from AB Biodisk Sweden and determining the MIC of chloramphenicol (in A g/ml). Clinical and Laboratory Standards Institute (CLSI) recommendations of A=8 A g/ml being sensitive, 16 A g/ml as intermediate and A 32 A g/ml as resistant were followed in interpreting the results. Results: Out of the 174 MRSA isolates, 132 (75.86%) isolates were susceptible to chloramphenicol with MICs of A=8 A g/ml, 38 (21.84%) were resistant A=32 A g/ml while 4 (2.30%) were in intermediate range with MIC of 16 A g/ml. Conclusion: Chloramphenicol has shown good in vitro activity against MRSA and is likely to have a key role in the treatment of MRSA infections providing us a good alternative to newer expensive antimicrobials in resource limited countries. (author)

Genotyping of coa and aroA Genes of Methicillin-Resistant Staphylococcus aureus Strains Isolated From Nasal Samples in Western Iran

OpenAIRE

Mohajeri, Parviz; Azizkhani, Samira; Farahani, Abbas; Norozi, Baharak

2016-01-01

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterial pathogen frequently isolated in both hospital and community environments. Methicillin-resistant Staphylococcus aureus is considered a major nosocomial pathogen that causes severe morbidity and mortality. Objectives: The main objective of this study was to determine the genotypes of MRSA strains isolated from the nares of hospitalized and community patients in Kermanshah Hospital, western Iran, by PCR-restriction fra...

Existing drug resistance among Staphylococcus spp. from raw milk samples in Khon Kaen province, Northeastern Thailand by direct quadriplex PCR

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Buppachat Trakarnchan

2017-10-01

Full Text Available To describe the proportion of methicillin resistant Staphylococcus aureus, and mupirocin resistant among the isolates from milk, three hundred and eighty-one samples were collected in Khon Kaen province, Thailand, during January to March, 2014. Quadriplex PCR was a method of choice. The occurrence of S. aureus and other Staphylococcus spp. were 21.26 and 34.12%, respectively. Among the 81 S. aureus isolates, 82.72 (67/81, 11.11 (9/81, and 6.17% (5/81 were S. aureus, S. aureus carrying mecA, and S. aureus harboring mupA genes, respectively. These two mutant genes may possibly be transferred to other bacteria in milk. Therefore, good hygienic practices and strict control may limit the spread.

Annual Surveillance Summary: Methicillin-Resistant Staphylococcus aureus (MRSA) Infections in the Military Health System (MHS), 2016

Science.gov (United States)

2017-06-01

Classifications .................................................................. 7 Section B – Antimicrobial Resistance and Use...368-2017 Section B – Antimicrobial Resistance and Use Regional Multidrug Resistance The 2016 annual incidence rate of MRSA among all MHS...Annual Surveillance Summary: Methicillin- Resistant Staphylococcus aureus (MRSA) Infections in the Military

Antibacterial activity of mupirocin (pseudomonic Acid A) against, clinical isolates of methicillin-resistant staphylococcus aureus

International Nuclear Information System (INIS)

Farooq, M.; Abbasi, S.A.; Butt, T.; Arain, M.A

2010-01-01

Colonized patients and health care workers are the main source of spread of methicillin resistant Staphylococcus aureus (MRSA) in hospitals. The elimination of nasal colonized MRSA plays a crucial role in infection control protocols. Mupirocin (pseudomonic acid A) is used for eradication of MRSA nasal carriage. Increasing use of pseudomonic acid A (mupirocin) has led to emergence of resistance. Objective To determine low and high level resistance of MRSA isolates from clinical specimens against mupirocin. Place and duration of study: Study was conducted at Department of Microbiology, Armed Forces Institute of Pathology, Rawalpindi from July 2006 to June 2007. Material and methods Three hundred methicillin-resistant Staphylococcus aureus isolates were studied. All clinical specimens were processed for culture and sensitivity. Staphylococcus aureus isolates were tested for methicillin resistance using 1 micro g oxacillin disk. The isolates were further tested by PCR for the presence of mecA gene. Minimum Inhibitory Concentration (MIC) of mupirocin against MRSA isolates was determined using agar dilution technique. Results Out of 300 MRSA isolates, 98% were found to have MlC against mupirocin as smaller than 4 micro g/mL. Remaining 2% isolates revealed low level resistance (MIC greater than 8 micro g/mL to 256 micro g/mL), no high level resistance (MIC greater than 512 micro g/mL) against mupirocin was detected. Conclusions: High level mupirocin resistance has not emerged so far in our setup. Due to increasing use of mupirocin, emergence of resistance against mupirocin among MRSA is a strong possibility. Strategy encompassing rational use of antimicrobials, hospital infection control, surveillance for the detection of mupirocin resistance and judicious use of this agent is required. (author)

Prevalence of Methicillin-Resistant Staphylococcus aureus and Other Staphylococcus Species in Raw Meat Samples Intended for Human Consumption in Benin City, Nigeria: Implications for Public Health.

Science.gov (United States)

Igbinosa, Etinosa O; Beshiru, Abeni; Akporehe, Lucy U; Oviasogie, Faith E; Igbinosa, Owen O

2016-09-24

The present study was designed to characterize methicillin-resistant staphylococci from raw meat. A total of 126 meat samples were obtained from open markets between February and April, 2015. Antimicrobial susceptibility testing was carried out using the disc diffusion method. Molecular profiling was conducted using 16S rRNA, mecA, nuc, and PVL gene signatures were detected by polymerase chain reaction assay. Fifty isolates of methicillin-resistant Staphylococcus spp. were detected in 26 (52%) pork, 14 (28%) beef and 10 (20%) chicken samples. The staphylococcal isolates were identified through partial 16S ribosomal ribonucleic acid (16S rRNA) nucleotide sequencing, and BLAST analysis of the gene sequence revealed 98%-100% staphylococcal similarity. All isolates from beef and chicken samples amplified the mecA gene, while 100% of the MRSA isolates amplified the PVL gene. The multidrug resistance profile (resistant to ≥1 antimicrobial agent in ≥3 classes of antimicrobial agents) of the staphylococcal isolates showed that 7 isolates were resistant to methicillin, penicillin, clindamycin, chloramphenicol, trimethoprim-sulfamethoxazole, kanamycin, amoxicillin, cloxacillin, erythromycin, vancomycin, and gentamycin. There was a significant regression effect from the multidrug-resistant profile on the number of isolates (p resistant strains within bacterial populations. The findings of the present study indicate that raw meats in the Benin metropolis were possibly contaminated with pathogenic and multi-drug resistant staphylococci strains and therefore could constitute a risk to public health communities.

The Effectiveness of Bacteriophages against Methicillin-Resistant Staphylococcus aureus ST398 Nasal Colonization in Pigs

NARCIS (Netherlands)

Verstappen, Koen M; Tulinski, Pawel; Duim, Birgitta; Fluit, Ad C; Carney, Jennifer; van Nes, Arie; Wagenaar, Jaap A

2016-01-01

UNLABELLED: Methicillin-resistant Staphylococcus aureus (MRSA) is an important colonizer in animals and an opportunistic pathogen in humans. In humans, MRSA can cause infections that might be difficult to treat because of antimicrobial resistance. The use of bacteriophages has been suggested as a

Nasal Staphylococcus aureus and methicillin-resistant Staphylococcus aureus carriage among college student athletes in northern Taiwan

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Hong-Kai Wang

2017-08-01

Full Text Available Of 259 college students in northern Taiwan surveyed, nasal carriage rate of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA was 22.4% and 1.54%, respectively and no significant difference was found between athlete students and non-athlete students. Three of four MRSA isolates belonged to sequence type 59, the endemic community clone.

Mechanisms of methicillin resistance in Staphylococcus aureus and methods for laboratory detection.

Science.gov (United States)

Jorgensen, J H

1991-01-01

Three distinctly different mechanisms of methicillin resistance have been described in Staphylococcus aureus. The best-documented and probably most important mechanism is production of a unique, low affinity penicillin-binding protein, PBP 2a. Strains possessing PBP 2a are resistant to methicillin, oxacillin, and probably all other currently available beta-lactam antibiotics. Two additional mechanisms of reduced susceptibility to methicillin have been described. Borderline resistance (BORSA) to the semi-synthetic penicillins has been attributed to the hyperproduction of normal staphylococcal beta-lactamase. A third mechanism has recently been advanced that describes an intermediate level of resistance to methicillin due to production of modified, normal PBPs with reduced affinity for beta-lactams (MODSA). Little is known regarding the prevalence or clinical significance of the BORSA and MODSA strains. The most reliable in vitro susceptibility test methods for detecting MRSA (strains possessing PBP 2a) include the microdilution minimum inhibitory concentration (MIC) test (with 2% NaCl supplemented broth), the oxacillin agar screen plate test (incorporating 6 micrograms/ml oxacillin in 4% NaCl supplemented agar), and the National Committee for Clinical Laboratory Standards (NCCLS) disk diffusion test with oxacillin. All three methods use direct inoculum preparation and incubation of tests at 35 degrees C for a full 24 hours.

Methicillin-resistant Staphylococcus aureus: a controversial food-borne pathogen.

Science.gov (United States)

Sergelidis, D; Angelidis, A S

2017-06-01

Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of severe healthcare-associated (HA) infections. Although during the last decade the incidence of HA invasive infections has dropped, the incidence of community-associated MRSA (CA-MRSA) infections has risen among the general population. Moreover, CA-MRSA, livestock-associated MRSA (LA-MRSA) and HA-MRSA (HA-MRSA) can be found in foods intended for human consumption. Several studies from different geographical areas have reported the presence of enterotoxin genes in several MRSA food isolates. Molecular typing studies have revealed genetic relatedness of these enterotoxigenic isolates with isolates incriminated in human infections. The contamination sources for foods, especially animal-origin foods, may be livestock as well as humans involved in animal husbandry and food-processing. Under favourable environmental conditions for growth and enterotoxin production, enterotoxigenic S. aureus isolates present in foods can cause staphylococcal food poisoning (SFP), irrespective of the contamination origin. Owing to the typically moderate clinical manifestations of SFP, the S. aureus strains responsible for SFP (cases or outbreaks) are frequently either not identified or not further characterized. Antimicrobial susceptibility testing is rarely performed, because administration of antimicrobial therapy is not required in the vast majority of cases. Staphylococcal food poisoning is the result of consumption of foods with preformed enterotoxins. Hence, similar to methicillin-sensitive enterotoxigenic S. aureus, enterotoxigenic MRSA can also act as food-borne pathogens upon favourable conditions for growth and enterotoxin production. The severity of the intoxication is not related to the antimicrobial resistance profile of the causative S. aureus strain and therefore MRSA food-borne outbreaks are not expected to be more severe. This review evaluates the potential of methicillin-resistant Staphylococcus

Autolysis of methicillin-resistant and -susceptible Staphylococcus aureus.

Science.gov (United States)

Gustafson, J E; Berger-Bächi, B; Strässle, A; Wilkinson, B J

1992-01-01

The autolytic activities, including unstimulated, Triton X-100-stimulated, and daptomycin-induced, of various sets of methicillin-resistant and related methicillin-susceptible strains were compared. Faster rates of autolysis were noted in two heterogeneous methicillin-resistant transductants than in their methicillin-susceptible parental recipients, in a heterogeneous resistant strain than in a susceptible derivative created by chemical mutagenesis, and in a homogeneous resistant strain than in a derivative that had decreased methicillin resistance and was created by transposon Tn551 mutagenesis. These results suggest that the presence of the methicillin resistance region, mec, either directly or indirectly through an interaction with other host genes, confers a faster rate of autolysis on strains. Various auxilliary genes are known to affect methicillin resistance expression, and one of these genes, femA, was necessary for the expression of this faster rate of autolysis. These differences in autolytic activities were not observed in isolated crude cell walls retaining autolytic activities, suggesting different modes of regulation of autolysins in intact cells and isolated walls. In contrast, one homogeneous, highly resistant strain, DU4916, had a lower autolytic activity than did derived heterogeneous resistant and susceptible strains created by chemical mutagenesis and a strain that had decreased resistance and was created by transposon mutagenesis. Our observations suggest that methicillin resistance expression is associated with an enhanced rate of autolysis, in heterogeneous resistant strains at least. Images PMID:1320363

The effectiveness of bacteriophages against methicillin-resistant Staphylococcus aureus ST398 nasal colonization in pigs

NARCIS (Netherlands)

Verstappen, Koen M.; Tulinski, Pawel; Duim, Birgitta; Fluit, Ad C.; Carney, Jennifer; Nes, Van Arie; Wagenaar, Jaap A.

2016-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) is an important colonizer in animals and an opportunistic pathogen in humans. In humans, MRSA can cause infections that might be difficult to treat because of antimicrobial resistance. The use of bacteriophages has been suggested as a potential

Temperature Effect on the Susceptibility of Methicillin-Resistant Staphylococcus aureus to Four Different Cephalosporins

OpenAIRE

Canawati, Hanna N.; Witte, Joyce L.; Sapico, Francisco L.

1982-01-01

Forty isolates of methicillin-resistant Staphylococcus aureus were tested for in vitro susceptibility to cephalothin, cefamandole, cefotaxime, and moxalactam, using the disk diffusion and microbroth dilution methods at incubation temperatures of 30 and 35°C. Resistance to all four antibiotics was more clearly evident at an incubation temperature of 30°C.

Nasal carriage of Methicillin-resistant Staphylococcus aureus among healthy population of Kashmir, India

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B A Fomda

2014-01-01

Full Text Available Background: Nasal colonisation with community acquired methicillin resistant Staphylococcus aureus (CA-MRSA is being increasingly reported, especially in places where people are in close contact and where hygiene is compromised. The aim of this study was to find out prevalence of methicillin resistant S.aureus (MRSA colonising anterior nares of healthy subjects. Materials and Methods: Nasal swabs of healthy subjects were collected aseptically and cultured using standard microbiological protocols. Antibiotic susceptibility was done by Kirby-Bauer disc diffusion method according to CLSI guidelines. Methicillin resistance was detected by cefoxitin disc diffusion method and confirmed by minimum inhibitory concentration (MIC and amplification of mecA gene by PCR. Strain typing of MRSA strains was done by PFGE. Results: Out of 820 samples, S.aureus was isolated from 229 (27.92% subjects. Of the 229 isolates, 15 were methicillin resistant. All S. aureus isolates were susceptible to vancomycin. Nasal carriage of MRSA was found to be 1.83% among healthy population. The isolates were found to be polyclonal by PFGE analysis. Conclusion: High prevalence of MRSA is a cause of concern and strategies to interrupt transmission should be implemented.

Rapid Increase of Genetically Diverse Methicillin-Resistant Staphylococcus aureus, Copenhagen, Denmark

DEFF Research Database (Denmark)

Bartels, Mette Damkjær; Boye, Kit; Larsen, Anders Rhod

2007-01-01

In Copenhagen, methicillin-resistant Staphylococcus aureus (MRSA) accounted for <15 isolates per year during 1980-2002. However, since 2003 an epidemic increase has been observed, with 33 MRSA cases in 2003 and 110 in 2004. We analyzed these 143 cases epidemiologically and characterized isolates ...... and soft tissue infections dominated. CO-MRSA with diverse genetic backgrounds is rapidly emerging in a low MRSA prevalence area. Udgivelsesdato: October...

Evidence for Human Adaptation and Foodborne Transmission of Livestock-Associated Methicillin-Resistant Staphylococcus aureus

DEFF Research Database (Denmark)

Larsen, Jesper; Stegger, Marc; Andersen, Paal S.

2016-01-01

We investigated the evolution and epidemiology of a novel live-stock-associated methicillin-resistant Staphylococcus aureus strain, which colonizes and infects urban-dwelling Danes even without a Danish animal reservoir. Genetic evidence suggests both poultry and human adaptation, with poultry meat...

The changing face of community-acquired methicillin-resistant Staphylococcus aureus

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P Kale

2016-01-01

Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA is an important cause of infection, both in hospitalised patients with significant healthcare exposure and in patients without healthcare risk factors. Community-acquired methicillin-resistant S. aureus (CA-MRSA are known for their rapid community transmission and propensity to cause aggressive skin and soft tissue infections and community-acquired pneumonia. The distinction between the healthcare-associated (HA-MRSA and CA-MRSA is gradually fading owing to the acquisition of multiple virulence factors and genetic elements. The movement of CA-MRSA strains into the nosocomial setting limits the utility of using clinical risk factors alone to designate community or HA status. Identification of unique genetic characteristics and genotyping are valuable tools for MRSA epidemiological studies. Although the optimum pharmacotherapy for CA-MRSA infections has not been determined, many CA-MRSA strains remain broadly susceptible to several non-β-lactam antibacterial agents. This review aimed at illuminating the characteristic features of CA-MRSA, virulence factors, changing clinical settings and molecular epidemiology, insurgence into the hospital settings and therapy with drug resistance.

Incidencia y fármaco-resistencia de cepas de Staphylococcus spp aisladas de exudados conjuntivales Incidence and drug-resistance of Staphylococcus spp strains isolated from conjunctival swabs

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Andrés Noya Cabaña

2010-01-01

Full Text Available OBJETIVO: Determinar la incidencia de cepas del género Staphylococcus aisladas de exudados conjuntivales y analizar su resistencia frente a diferentes antimicrobianos. MÉTODOS: Se realizó un estudio observacional descriptivo retrospectivo en el que se revisaron 3554 exudados conjuntivales a pacientes que acudieron en el período comprendido entre enero de 2002 a diciembre de 2003 y desde enero de 2005 hasta diciembre de 2007 al Instituto Cubano de Oftalmología «Ramón Pando Ferrer» por presentar un diagnóstico de infección ocular externa. RESULTADOS: Se aislaron 874 cepas de Staphylococcus aureus para un 47,5 % y 965 cepas de Staphylococcus spp. coagulasa negativa con prueba de patogenicidad positiva para un 52,4 %. En 69 de esos exudados los cultivos presentaron etiología mixta con dos bacterias diferentes, para el 3,7 %. Se determinaron los porcentajes de resistencia a las cepas aisladas pertenecientes al género Staphylococcus. CONCLUSIONES: Se encontró una alta incidencia de las especies del género Staphylococcus en las infecciones oculares, así como se pudo apreciar que la menor fármaco-resistencia para Staphylococcus aureus y Staphylococcus spp. coagulasa negativa correspondieron a los antimicrobianos ciprofloxacina y amikacina. La mayor fármaco-resistencia de las cepas de Staphylococcus aureus correspondió a eritromicina y tetraciclina y en Staphylococcus spp coagulasa negativa fue frente a la tetraciclina.OBJECTIVE: To determine the incidence of Staphylococcus strains isolated from conjunctival swaps and their resistance to several antimicrobial agents. METHODS: A retrospective, descriptive and observational study was performed to review 3554 conjunctival swabs from patients who went to "Ramón Pando Ferrer" Institute of Ophthalmology in the period from January 2002 to December 2009 due to a diagnosis of external ocular infection. RESULTS: From the total of conjunctival swabs, 874 Staphylococcus aureus strains (47.5 % and

METHICILLIN RESISTANCE IN STAPHYLOCOCCAL ISOLATES ...

African Journals Online (AJOL)

The study assessed the importance of Staphylococcus aureus as a urinary pathogen and the incidence of multidrug resistant (MDR), methicillin-resistant Staphylococcus aureus (MRSA). A total of 86 staphylococcal isolates made up of 50 clinical isolates from urine samples submitted to the Medical Microbiology Laboratory ...

A laboratory study of susceptibility of methicillin resistant staphylococcus aureus (MRSA)

International Nuclear Information System (INIS)

Bukhari, M.H.; Iqbal, N.; Naeem, S.; Qureshi, G.R.; Naveed, I.A.; Iqbal, A.; Khatoon, N.

2004-01-01

Objective: To study the mode of infection, incidence of methicillin resistant staphylococcus aureus (MRSA) and their susceptibility against glycopeptides and fucidic acid, so that awareness may be created for consultants against such notorious rapidly spreading bacteria and recommendation can be made for their prevention and control. Methods: The specimens from various infections suspected on clinical ground were processed by standard methods and antibiotic susceptibility testing of all the 350 S. aureus and 135 MRSA isolates was done by using modified Kirby Bauer Disc diffusion technique. Results: Of 350 positive S.aureus cultures, 135 were found to be Methicillin resistant (38.5%) which showed susceptibility 96%, 94% and 86% to Vancomycin, Teicoplanin and Fucidic acid respectively. Conclusion: This study showed a high incidence of MRSA at Mayo Hospital Lahore, Glycopeptides and Fucidic acid were found to be valuable antibiotics against MRSA. (author)

Controlling methicillin-resistant Staphylococcus aureus : Quantifying the effects of interventions and rapid diagnostic testing

NARCIS (Netherlands)

Bootsma, M.C.; Diekmann, O.; Bonten, M.J.M.

2006-01-01

Control of nosocomial transmission of methicillin-resistant Staphylococcus aureus (MRSA) has been unsuccessful in most countries. Yet, some countries have maintained low endemic levels by implementing nationwide MRSA-specific infection control measures, such as ‘‘search & destroy’’ (S&D). These

Successful treatment for carriage of methicillin-resistant Staphylococcus aureus and importance of follow-up

NARCIS (Netherlands)

F.P.N. Mollema (Femke); J.A. Severin (Juliëtte); J.L. Nouwen (Jan); A. Ott (Alewijn); H.A. Verbrugh (Henri); A. Voss (Andreas)

2010-01-01

textabstractWith this prospective observational follow-up study of 165 methicillin-resistant Staphylococcus aureus (MRSA)-positive individuals (23 health care workers and 142 patients), we determined that our MRSA eradication therapy protocol results in a high success rate (81%). Five or more

Isolation of methicillin-resistant Staphylococcus pseudintermedius from breeding dogs.

Science.gov (United States)

Rota, Ada; Milani, Chiara; Drigo, Ilenia; Drigo, Michele; Corrò, Michela

2011-01-01

The overuse of antimicrobials can select resistant bacteria strains; staphylococci have the ability to become resistant to all beta-lactam antimicrobials and are a significant concern in human medicine and a growing issue for veterinary medicine. Because antimicrobials are sometimes incorrectly used in breeding kennels, the objective of the work was to assess the occurrence of methicillin-resistant coagulase-positive staphylococci in breeding dogs. The research was carried out in 13 kennels that were allotted to three categories according to the intensity of antimicrobial use. Vaginal and milk swabs were taken from 87 healthy bitches around parturition and also from multiple organs of 27 of their pups that died within the first 2 weeks. Standard bacteriological examinations were carried out and coagulase-positive staphylococci were identified. All the coagulase-positive staphylococci resulted to be Staphylococcus pseudintermedius. Susceptibility to oxacillin and the presence of the mecA gene were tested. Nine out of 89 strains (six isolated from the bitches' milk and three from dead puppies, all belonging to kennels characterized by an excessive use of antimicrobials) were multidrug-resistant, methicillin-resistant and mecA positive. Our results confirm that excessive use of antimicrobials entails the risk of selecting resistant staphylococci strains. Our data also indicate that the bacterial flora of healthy dogs belonging to specific populations may act as a reservoir of resistance genes. Copyright © 2011 Elsevier Inc. All rights reserved.

Methicillin resistance of airborne coagulase-negative staphylococci in homes of persons having contact with a hospital environment.

Science.gov (United States)

Lis, Danuta O; Pacha, Jerzy Z; Idzik, Danuta

2009-04-01

The persons having contact with a hospital environment (hospital personnel workers and discharged patients) are highly exposed to colonization with multidrug-resistant bacteria. The aim of this study was to evaluate the airborne Staphylococcus genus features in homes in which inhabitants have had contact with the hospital environment. Airborne bacteria were collected using a 6-stage Anderson impactor. The Staphylococcus species composition and resistance to methicillin, and other antimicrobial agents among 3 coagulase-negative staphylococci (CNS) species (S cohnii spp cohnii, S epidermidis, S hominis), were determined. Antibiotic resistance of isolates was tested using the agar screen method with methicillin, the polymerase chain reaction technique to detect the mecA gene, and the disk diffusion method. A higher prevalence of methicillin-resistant (MR) strains among the species isolated (40% of S epidermidis, 40% of S hominis, and 60% of S cohnii spp cohnii) was found in homes of persons who had contact with a hospital environment compared with the reference homes (only 12% of S hominis). The mecA gene was revealed in all MR S epidermidis strains and in some MR S hominis (50%) and S cohnii spp cohnii (33%) strains. All isolated MR CNS strains were susceptible to vancomycin, rifampicin, and linezolid. High numbers of airborne multidrug-resistant MR CNS in the homes of persons having contact with a hospital environment indicates that such inhabitants pose a risk of intrafamilial spreading of MR strains via air.

Toxin Mediates Sepsis Caused by Methicillin-Resistant Staphylococcus epidermidis.

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Li Qin

2017-02-01

Full Text Available Bacterial sepsis is a major killer in hospitalized patients. Coagulase-negative staphylococci (CNS with the leading species Staphylococcus epidermidis are the most frequent causes of nosocomial sepsis, with most infectious isolates being methicillin-resistant. However, which bacterial factors underlie the pathogenesis of CNS sepsis is unknown. While it has been commonly believed that invariant structures on the surface of CNS trigger sepsis by causing an over-reaction of the immune system, we show here that sepsis caused by methicillin-resistant S. epidermidis is to a large extent mediated by the methicillin resistance island-encoded peptide toxin, PSM-mec. PSM-mec contributed to bacterial survival in whole human blood and resistance to neutrophil-mediated killing, and caused significantly increased mortality and cytokine expression in a mouse sepsis model. Furthermore, we show that the PSM-mec peptide itself, rather than the regulatory RNA in which its gene is embedded, is responsible for the observed virulence phenotype. This finding is of particular importance given the contrasting roles of the psm-mec locus that have been reported in S. aureus strains, inasmuch as our findings suggest that the psm-mec locus may exert effects in the background of S. aureus strains that differ from its original role in the CNS environment due to originally "unintended" interferences. Notably, while toxins have never been clearly implied in CNS infections, our tissue culture and mouse infection model data indicate that an important type of infection caused by the predominant CNS species is mediated to a large extent by a toxin. These findings suggest that CNS infections may be amenable to virulence-targeted drug development approaches.

Experiences of nursing staff caring for patients with methicillin-resistant Staphylococcus aureus.

Science.gov (United States)

Andersson, H; Andreassen Gleissman, S; Lindholm, C; Fossum, B

2016-06-01

Methicillin-resistant Staphylococcus aureus is a resistant variant of S. aureus and can cause pneumonia, septicaemia and, in some cases, death. Caring for patients with antibiotic resistant bacteria is a challenge for healthcare personnel. There is a risk of spreading the bacteria among patients and of healthcare personnel being infected themselves. To describe nursing staffs' experiences of caring for patients with methicillin-resistant S. aureus in Sweden. A descriptive qualitative approach was used and 15 nurses from different hospitals and care units, including emergency and geriatric wards and nursing homes in Stockholm, were interviewed. All nurses had been involved in the care of patients with methicillin-resistant S. aureus, but not on a regular basis. The interviews were analysed using qualitative content analysis. Three themes emerged from the data: feeling ignorant, afraid and insecure, feeling competent and secure and feeling stressed and overworked. The more knowledge the nurses acquired about methicillin-resistant S. aureus, the more positive was their attitude to caring for these patients. Caring for patients with methicillin-resistant S. aureus without adequate knowledge of how to protect oneself and other patients against transmission may provoke anxiety among personnel. Guidelines, memos and adequate information at the right time are of central importance. Healthcare personnel must feel safe in their role as caregivers. All patients have the right to have the same quality of care regardless of the diagnosis and a lack of knowledge influences the level of care given. This study demonstrates the importance of education when caring for patients with infectious diseases. Hopefully, knowledge gained from our study can provide guidance for future health care when new diseases and infections occur. © 2016 International Council of Nurses.

Livestock-associated methicillin resistant Staphylococcus aureus in pigs - prevalence, risk factors and transmission dynamics

NARCIS (Netherlands)

Broens, E.M.

2011-01-01

In 2004, an association between human carriage of methicillin resistant Staphylococcus aureus (MRSA) and contact with pigs was found. To assess the implications of this finding for veterinary and public health more insight into the prevalence, risk factors and transmission dynamics of

Prevalence and characterization of methicillin-resistant Staphylococcus aureus carrying mecA or mecC and methicillin-susceptible Staphylococcus aureus in dairy sheep farms in central Italy.

Science.gov (United States)

Giacinti, G; Carfora, V; Caprioli, A; Sagrafoli, D; Marri, N; Giangolini, G; Amoruso, R; Iurescia, M; Stravino, F; Dottarelli, S; Feltrin, F; Franco, A; Amatiste, S; Battisti, A

2017-10-01

Between January and May 2012, a total of 286 bulk tank milk samples from dairy sheep farms located in central Italy were tested for the presence of Staphylococcus aureus. One hundred fifty-three samples were positive for S. aureus (53.5%), with an average count of 2.53 log cfu/mL. A total of 679 S. aureus colonies were screened for methicillin resistance by the cefoxitin disk diffusion test, and 104 selected cefoxitin-susceptible isolates were also tested for their susceptibility to other antimicrobials representative of the most relevant classes active against Staphylococcus spp. by using the Kirby-Bauer disk diffusion method. Two methicillin-resistant Staphylococcus aureus (MRSA) isolates, carrying respectively the mecA and the mecC genes, were detected in 2 samples from 2 different farms (prevalence 0.7%). The mecA-positive MRSA isolate was blaZ positive, belonged to spa type t127, sequence type (ST)1, clonal complex (CC)1, carried a staphylococcal cassette chromosome mec (SCCmec) type IVa, and was phenotypically resistant to all the β-lactams tested and to erythromycin, streptomycin, kanamycin, and tetracycline. The mecC-positive MRSA isolate was negative for the chromosomally or plasmid-associated blaZ gene but positive for the blaZ allotype associated with SCCmec XI (blaZ-SCCmecXI), belonged to spa type 843, ST(CC)130, carried a SCCmec type XI, and was resistant only to β-lactams. Both MRSA were negative for the presence of specific immune-evasion and virulence genes such as those coding for the Panton-Valentine leucocidin, the toxic shock syndrome toxin 1, and the immune evasion cluster genes. Regarding the presence of the major S. aureus enterotoxin genes, the mecC-positive MRSA tested negative, whereas the ST (CC)1 mecA-positive MRSA harbored the seh gene. Among the 104 methicillin-susceptible S. aureus isolates examined for antimicrobial susceptibility, 63 (60.58%) were susceptible to all the antimicrobials tested, and 41 (39.42%) were resistant to at

Detection of Methicillin-Resistant Staphylococci Isolated from Food Producing Animals: A Public Health Implication

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Etinosa O. Igbinosa

2016-07-01

Full Text Available The emergence of antibiotic-resistant bacteria in food animals is a potential public health concern. Staphylococci are a significant opportunistic pathogen both in humans and dairy cattle. In the present study, the genotypic characterization of methicillin-resistant staphylococcal strains recovered from dairy cattle in a rural community (Okada, Edo State, Nigeria was investigated. A total of 283 samples from cattle (137 milk samples and 146 nasal swabs were assessed between February and April 2015. Antimicrobial susceptibility was performed by Kirby-Bauer disc diffusion method. Polymerase chain reaction (PCR assay was employed for the detection of 16S rRNA, mecA and Panton-Valentine Leucocidinis (PVL genes. The staphylococcal strains were identified through partial 16S ribosomal ribonucleic acids (rRNA nucleotide sequencing, and Basic Local Alignment Search Tool (BLAST analysis of the gene sequence showed that the staphylococcal strains have 96%–100% similarity to Staphylococcus aureus (30, S. epidermidis (17, S. haemolyticus (15, S. saprophyticus (13, S. chromogenes (8, S. simulans (7, S. pseudintermedius (6 and S. xylosus (4. Resistance of 100% was observed in all Staphylococcus spp. against MET, PEN, CLN, CHL and SXT. Multi-drug resistant (MDR bacteria from nasal cavities and raw milk reveals 13 isolates were MDR against METR, PENR, AMXR, CLNR, CHLR, SXTR CLXR, KANR, ERYR, and VANR. Of all isolates, 100% harboured the mecA gene, while 30% of the isolates possess the PVL gene. All S. aureus harboured the PVL gene while other Staphylococcus spp. were negative for the PVL gene. The presence of methicillin-resistant Staphylococcus spp. isolates in dairy cattle is a potential public health risk and thus findings in this study can be used as a baseline for further surveillance.

Daptomycin approved in Japan for the treatment of methicillin-resistant Staphylococcus aureus

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Mori T

2012-02-01

Full Text Available Mao Hagihara1, Takumi Umemura1, Takeshi Mori1,2, Hiroshige Mikamo11Department of Infection Control and Prevention, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan; 2Division of Pharmaceutical Science, Faculty of Pharmacy, Meijo University, Nagoya, Aichi, JapanAbstract: Daptomycin is a lipoglycopeptide antibacterial drug that is rapidly bactericidal for methicillin-resistant Staphylococcus aureus (MRSA infection and has antibiotic activity against a wide range of Gram-positive organisms. It has been approved by the Ministry of Health, Labor and Welfare in Japan for the treatment for bacteremia, right-sided endocarditis, and skin and skin-structure infections, such as necrotizing fasciitis, due to MRSA on the basis of a Phase III trial conducted in Japan since July, 2011. In Japanese Phase I and III trials, daptomycin therapy given at 4 mg/kg and 6 mg/kg once per day was well tolerated and effective as standard therapy for the treatment of acute bacterial skin and skin-structure infections and bacteremia caused by MRSA, but side effects remain to be evaluated in large-scale trials.Keywords: daptomycin, methicillin-resistant Staphylococcus aureus (MRSA, Japan

European ST80 community-associated methicillin-resistant Staphylococcus aureus orbital cellulitis in a neonate

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Tsironi Evangelia E

2012-05-01

Full Text Available Abstract Background Methicillin-resistant Staphylococcus aureus is a serious cause of morbidity and mortality in hospital environment, but also, lately, in the community. This case report is, to our knowledge, the first detailed description of a community-associated methicillin-resistant S. aureus ST80 orbital cellulitis in a previously healthy neonate. Possible predisposing factors of microbial acquisition and treatment selection are also discussed. Case presentation A 28-day-old Caucasian boy was referred to our hospital with the diagnosis of right orbital cellulitis. His symptoms included right eye proptosis, periocular edema and redness. Empirical therapy of intravenous daptomycin, rifampin and ceftriaxone was initiated. The culture of pus yielded a methicillin-resistant S. aureus isolate and the molecular analysis revealed that it was a Panton-Valentine leukocidine-positive ST80 strain. The combination antimicrobial therapy was continued for 42days and the infection was successfully controlled. Conclusions Clinicians should be aware that young infants, even without any predisposing condition, are susceptible to orbital cellulitis caused by community-associated methicillin-resistant S. aureus. Prompt initiation of the appropriate empirical therapy, according to the local epidemiology, should successfully address the infection, preventing ocular and systemic complications.

Community-Associated Methicillin-Resistant Staphylococcus aureus Case Studies

Science.gov (United States)

Sowash, Madeleine G.; Uhlemann, Anne-Catrin

2014-01-01

Over the past decade, the emergence of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has changed the landscape of S. aureus infections around the globe. Initially recognized for its ability to cause disease in young and healthy individuals without healthcare exposures as well as for its distinct genotype and phenotype, this original description no longer fully encompasses the diversity of CA-MRSA as it continues to expand its niche. Using four case studies, we highlight a wide range of the clinical presentations and challenges of CA-MRSA. Based on these cases we further explore the globally polygenetic background of CA-MRSA with a special emphasis on generally less characterized populations. PMID:24085688

Strategies for Prevention of Methicillin Resistant Staphylococcus aureus (MRSA) Infections and Decolonization.

Science.gov (United States)

Kaushik, Ashlesha; Wagner, Cassie; Consoer, Hollie; Chatterjee, Archana

2016-12-01

Methicillin resistant Staphylococcus aureus (MRSA) invasive infections can be severe in the pediatric population with high morbidity and mortality. MRSA colonization can predispose to recurrent skin and soft tissue infections and invasive MRSA disease and is a frequent challenge faced by clinicians. This article reviews the importance of MRSA as a pathogen, MRSA colonization and various MRSA decolonization strategies. Copyright© South Dakota State Medical Association.

A genomic portrait of the emergence, evolution, and global spread of a methicillin-resistant Staphylococcus aureus pandemic

DEFF Research Database (Denmark)

Holden, Matthew T G; Hsu, Li-Yang; Kurt, Kevin

2013-01-01

The widespread use of antibiotics in association with high-density clinical care has driven the emergence of drug-resistant bacteria that are adapted to thrive in hospitalized patients. Of particular concern are globally disseminated methicillin-resistant Staphylococcus aureus (MRSA) clones that ...

Isolation, Identification and Antibacterial Susceptibility of Staphylococcus spp. Associated with the Mobile Phones of University Students.

Science.gov (United States)

Furuhata, Katsunori; Ishizaki, Naoto; Sogawa, Kazuyuki; Kawakami, Yasushi; Lee, Shin-Ichi; Sato, Masahiro; Fukuyama, Masafumi

2016-01-01

From May 2014 to February 2015, 319 university students (male, n=173; female n=146) of 18 to 24 years of age who carried mobile phones or computer tablets were selected as subjects. Staphylococcus spp. were detected in 101 of 319 samples (31.7%). In the present study, 11 strains of S. aureus were isolated and identified, not all of which were methicillin-resistant Staphylococcus aureus (MRSA). Overall, 14 species were identified, with 11 strains (10.9%) of S. xylosus being isolated at the highest frequency. Following this were eight strains (7.9%) of S. cohnii and seven strains (6.9%) each of S. capitis and S. haemolyticus. Staphylococcus spp. isolation was performed with bacterial samples obtained from the mobile phones of 22 specific subjects (males, n=12; females, n=10). Staphylococcus spp. isolation was performed on days -1, 7 and 30 of the experiment. Staphylococcus spp. were positively detected one or more times in 12 subjects (54.5%). In one subject (8.3%), all three tests were positive. Furthermore, two tests were positive in three (25.0%). In the eight remaining subjects (66.7%) Staphylococcus spp. were detected only once. For the three abovementioned tests, we investigated the pulsed-field gel electrophoresis (PFGE) patterns of the strains derived from the mobile phone and from the fingers of three subjects in whom the same bacterial species were isolated twice. From the cases with similarities between strains derived from the fingers and the mobile phones and cases, with consistency in the strains derived from the mobile phone at different times, commonality was observed in the strains derived from the fingers and mobile phones along with chronological uniformity in the strains derived from the mobile phones. A total of 101 Staphylococcus spp. strains were isolated from mobile phones. According to drug susceptibility tests, 99 strains (98.0%) were found to have some degree of resistance to drugs (excluding one strain each of S. aureus and S. haemolyticus

Hospitalizations and Deaths Caused by Methicillin-Resistant Staphylococcus aureus, United States, 1999?2005

OpenAIRE

Klein, Eili; Smith, David L.; Laxminarayan, Ramanan

2007-01-01

Hospital-acquired infections with Staphylococcus aureus, especially methicillin-resistant S. aureus (MRSA) infections, are a major cause of illness and death and impose serious economic costs on patients and hospitals. However, the recent magnitude and trend of these infections have not been reported. We used national hospitalization and resistance data to estimate the annual number of hospitalizations and deaths associated with S. aureus and MRSA from 1999 through 2005. During this period, t...

Annual Surveillance Summary: Methicillin-Resistant Staphylococcus aureus (MRSA) Infections in the Military Health System (MHS), 2015

Science.gov (United States)

2017-03-01

disproportionately affected groups without typical risk factors, such as children or young adults. 11,17,18 Within the MHS, the burden of MRSA infections in...America for the treatment of methicillin-resistant Staphylococcus aureus infectious in adults and children . Clin Infect Dis. 2011;52:1-38. 27. Lewis JS II...Accountability System SSTI skin and soft tissue infection UD unit dose UIC unit identification code US United States UTI urinary tract infection VRSA vancomycin-resistant Staphylococcus aureus

Comparison of in vitro efficacy of linezolid and vancomycin by determining their minimum inhibitory concentrations against methicillin resistant Staphylococcus aureus (MRSA)

International Nuclear Information System (INIS)

Kaleem, F.; Usman, J.; Hassan, A.

2011-01-01

Objectives: To compare the in vitro activities of vancomycin and linezolid against methicillin resistant Staphyloccus aureus in our set up to help in formulating a better empirical treatment and reduce the emergence of vancomycin resistant Staphylococcus aureus. Methods: The study was conducted over a period of 6 months(July 1, 2009 - Dec 1, 2009). Fifty Methicillin resistant Staphylococcus aureus isolated from the clinical isolates of Military Hospital Rawalpindi were subjected to the determination of Minimum inhibitory concentrations of linezolid and vancomycin using E-strips. Results: All the isolated organisms were uniformly susceptible to both the antibiotics. Vancomycin showed higher minimum inhibitory concentrations (MICs) as compared to linezolid MICs. Conclusion: This study suggests that linezolid and vancomycin have similar in vitro efficacy for methicillin resistant Staphyloccus aureus infections. (author)

Molecular epidemiology of clinical and carrier strains of methicillin resistant Staphylococcus aureus (MRSA in the hospital settings of north India

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Dar Mohammad J

2006-09-01

Full Text Available Abstract Background The study was conducted between 2000 and 2003 on 750 human subjects, yielding 850 strains of staphylococci from clinical specimens (575, nasal cultures of hospitalized patients (100 and eye & nasal sources of hospital workers (50 & 125 respectively in order to determine their epidemiology, acquisition and dissemination of resistance genes. Methods Organisms from clinical samples were isolated, cultured and identified as per the standard routine procedures. Susceptibility was measured by the agar diffusion method, as recommended by the Nat ional Committee for Clinical Laboratory Standards (NCCLS. The modified method of Birnboin and Takahashi was used for isolation of plasmids from staphylococci. Pulsed-field gel electrophoresis (PFGE typing of clinical and carrier Methicillin resistant Staphylococcus aureus (MRSA strains isolated during our study was performed as described previously. Results It was shown that 35.1% of Staphylococcus aureus and 22.5% of coagulase-negative staphylococcal isolates were resistant to methicillin. Highest percentage of MRSA (35.5% was found in pus specimens (n = 151. The multiple drug resistance of all MRSA (n = 180 and Methicillin resistant Coagulase-negative Staphylococcus aureus (MRCNS (n = 76 isolates was detected. In case of both methicillin-resistant as well as methicillin-sensitive Saphylococcal isolates zero resistance was found to vancomycin where as highest resistance was found to penicillin G followed by ampicillin. It was shown that the major reservoir of methicillin resistant staphylococci in hospitals are colonized/infected inpatients and colonized hospital workers, with carriers at risk for developing endogenous infection or transmitting infection to health care workers and patients. The results were confirmed by molecular typing using PFGE by SmaI-digestion. It was shown that the resistant markers G and T got transferred from clinical S. aureus (JS-105 to carrier S. aureus (JN-49

Draft Genome Sequences of Staphylococcus aureus AMRF1 (ST22) and AMRF2 (ST672), Ocular Methicillin-Resistant Isolates

KAUST Repository

Velusamy, Nithya

2014-03-20

Sequence type 22 (ST22) and ST672 are the two major emerging clones of community-acquired methicillin-resistant Staphylococcus aureus in India. ST672 strains were found to cause severe ocular infections. We report the draft genome sequences of two emerging strains of methicillin-resistant S. aureus, AMRF1 (ST22) and AMRF2 (ST672), isolated from patients with ocular infections.

Draft Genome Sequences of Staphylococcus aureus AMRF1 (ST22) and AMRF2 (ST672), Ocular Methicillin-Resistant Isolates

KAUST Repository

Velusamy, Nithya; Prakash, Logambiga; Neelamegam, Sivakumar; Antony, Aju; Prajna, Lalitha; Mohankumar, Vidyarani; Devarajan, Bharanidharan

2014-01-01

Sequence type 22 (ST22) and ST672 are the two major emerging clones of community-acquired methicillin-resistant Staphylococcus aureus in India. ST672 strains were found to cause severe ocular infections. We report the draft genome sequences of two emerging strains of methicillin-resistant S. aureus, AMRF1 (ST22) and AMRF2 (ST672), isolated from patients with ocular infections.

Comparing Whole-Genome Sequencing with Sanger Sequencing for spa Typing of Methicillin-Resistant Staphylococcus aureus

DEFF Research Database (Denmark)

Bartels, Mette Damkjaer; Petersen, Andreas; Worning, Peder

2014-01-01

spa typing of methicillin-resistant Staphylococcus aureus (MRSA) has traditionally been done by PCR amplification and Sanger sequencing of the spa repeat region. At Hvidovre Hospital, Denmark, whole-genome sequencing (WGS) of all MRSA isolates has been performed routinely since January 2013, and ...

Endemic methicillin-resistant Staphylococcus aureus: Nurses' risk perceptions and attitudes.

Science.gov (United States)

Pedro, Ana Luisa; Sousa-Uva, António; Pina, Elaine

2014-10-01

Dissemination of methicillin-resistant Staphylococcus aureus (MRSA) remains one of the most difficult challenges for prevention, control, and treatment of health care-associated infections. A survey and interviews were conducted on nurses from a hospital center. We found that most nurses' perceived risk of acquiring MRSA related to themselves (72%), other nurses (88.5%), and patients (97.8%). This perception influences attitudes, leading to compliance with the existing recommendations. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Methicillin-resistant Staphylococcus aureus in horses and horse personnel: An investigation of several outbreaks

NARCIS (Netherlands)

Duijkeren, van E.; Moleman, M.; Oldruitenborgh-Oosterbaan, M.M.S.; Multem, J.; Troelstra, A.; Fluit, A.C.; Wamel, W.J.B.; Houwers, D.J.; Neeling, de A.J.; Wagenaar, J.A.

2010-01-01

At the Veterinary Microbiological Diagnostic Center, the Netherlands, the percentage of methicillin-resistant Staphylococcus aureus (MRSA) isolates found in equine clinical samples increased from 0% in 2002 to 37% in 2008. MRSA of spa-type t064, belonging to MLST ST8 and spa-types t011 and t2123,

Methicillin-resistant Staphylococcus aureus in horses and horse personnel: An investigation of several outbreaks

NARCIS (Netherlands)

Duijkeren, E. van; Moleman, M.; Sloet van Oldruitenborgh-Oosterbaan, M.M.; Multem, J.D.; Troelstra, A.; Fluit, A.C.; Wamel, W.J.B. van; Houwers, D.J.; Neeling, A.J. de; Wagenaar, J.A.

2009-01-01

At the Veterinary Microbiological Diagnostic Center, the Netherlands, the percentage of methicillin-resistant Staphylococcus aureus (MRSA) isolates found in equine clinical samples increased from 0% in 2002 to 37% in 2008. MRSA of spa-type t064, belonging to MLST ST8 and spa-types t011 and t2123,

Frequency of methicillin resistant Staphylococcus aureus in health care

Directory of Open Access Journals (Sweden)

Somayeh Rahimi-Alang

2011-03-01

Full Text Available Background: Methicillin resistant Staphylococcus aureus (MRSA is one of the most important pathogen in hospitals. Healthcare personnel are the main source of nosocomial infections and identification and control of MRSA carriers can reduce incidence of infections. The aim of this study was to determine the prevalence of MRSA and their antibiotic susceptibility profile among healthcare workers in Gorgan.Materials and Method: 333 healthcare workers were participated in this cross-sectional study in 2009. Samples were taken with sterile cotton swabs from both anterior nares and hands. Swabs were plated immediately on to the mannitol salt agar. Suspected colonies were confirmed as S. aureus by Gram staining, catalase, coagulase and DNase tests. Minimum inhibition concentration by micro dilution broth method was used to determine methicillin resistant strains. Antimicrobial susceptibility to other antibiotics was performed according to NCCLS guidelines by disc diffusion method.Result: Frequency of S.aureus and MRSA carriers among healthcare workers was 24% and 3% respectively. The highest rate of S. aureus and MRSA carriers were observed in operating room staff. Resistance to penicillin was seen in 97.5% of isolates and all strains were sensitive to vancomycin.Conclusions: Frequency of S. aureus and MRSA in healthcare workers was median and rather low respectively. Continual monitoring and control of carriers can reduce distribution of this organism and their infections

Short communication: β-Lactam resistance and vancomycin heteroresistance in Staphylococcus spp. isolated from bovine subclinical mastitis.

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Mello, Priscila Luiza; Pinheiro, Luiza; Martins, Lisiane de Almeida; Brito, Maria Aparecida Vasconcelos Paiva; Ribeiro de Souza da Cunha, Maria de Lourdes

2017-08-01

The use of antimicrobial agents has led to the emergence of resistant bacterial strains over a relatively short period. Furthermore, Staphylococcus spp. can produce β-lactamase, which explains the survival of these strains in a focus of infection despite the use of a β-lactam antibiotic. The aim of this study was to evaluate the resistance of Staphylococcus spp. isolated from bovine subclinical mastitis to oxacillin and vancomycin (by minimum inhibitory concentration) and to detect vancomycin heteroresistance by a screening method. We also evaluated β-lactamase production and resistance due to hyperproduction of this enzyme and investigated the mecA and mecC genes and performed staphylococcal cassette chromosome mec typing. For this purpose, 181 Staphylococcus spp. isolated from mastitis subclinical bovine were analyzed. Using the phenotypic method, 33 (18.2%) of Staphylococcus spp. were resistant to oxacillin. In contrast, all isolates were susceptible to vancomycin, and heteroresistance was detected by the screening method in 13 isolates. Production of β-lactamase was observed in 174 (96%) of the Staphylococcus spp. isolates. The mecA gene was detected in 8 isolates, all of them belonging to the species Staphylococcus epidermidis, and staphylococcal cassette chromosome mec typing revealed the presence of type I and type IV isolates. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Methicillin-resistant Staphylococci in companion animals

DEFF Research Database (Denmark)

Baptiste, Keith Edward; Williams, Kerry; Williams, Nicola J.

2005-01-01

We determined the molecular characteristics of methicillin-resistant staphylococci from animals and staff at a small animal and equine hospital. Methicillin-restistant Staphylococcus aureus identical to human EMRSA-15 was found in dogs and hospitalstaff. In contrast, 5 distinct MRSA strains were...

Wounds, Functional Disability, and Indwelling Devices Are Associated With Cocolonization by Methicillin-Resistant Staphylococcus aureus and Vancomycin-Resistant Enterococci in Southeast Michigan

OpenAIRE

Flannery, Erika L.; Wang, Linda; Zöllner, Sebastian; Foxman, Betsy; Mobley, Harry L. T.; Mody, Lona

2011-01-01

Cocolonization with methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) is a precursor to vancomycin-resistant S. aureus emergence. MRSA/VRE cocolonization incidence is higher among skilled nursing facility residents with functional disability and indwelling devices and occurs more frequently in wounds than other anatomical sites.

Rapid detection of methicillin resistance in Staphylococcus aureus isolates by the MRSA-screen latex agglutination test

NARCIS (Netherlands)

W.B. van Leeuwen (Willem); C. van Pelt (Cindy); A. Luijendijk (Ad); H.A. Verbrugh (Henri); W.H.F. Goessens (Wil)

1999-01-01

textabstractThe slide agglutination test MRSA-Screen (Denka Seiken Co., Niigata, Japan) was compared with the mecA PCR ("gold standard") for the detection of methicillin resistance in Staphylococcus aureus. The MRSA-Screen test detected the penicillin-binding protein 2a

New antimicrobial combinations: substituted chalcones- oxacillin against methicillin resistant Staphylococcus aureus

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Juan Manuel Talia

2011-06-01

Full Text Available Staphylococcus aureus, the most virulent Staphylococcus species, is also the prevalent pathogen isolated from hospitalized patients and the second most common from patients in outpatient settings. In general, bacteria have the genetic ability to transmit and acquire resistance to drugs, which are utilized as therapeutic agents. Related studies of antimicrobial activity indicate that crude extracts containing flavonoids, triterpenes and steroids have showed significative activity against several Staphylococcus aureus strains. Combination effects between flavonoids and antibiotics also have been reported. The aim of the present work was to investigate in vitro synergism between several chalcones substituted in combination with oxacillin, an antibiotic used conventionally against S. aureus ATCC 43 300 that is resistant to meticillin, using the kinetic turbidimetric method developed earlier. The results were satisfactory for all assayed combinations and in accordance with the mechanism of bacteriostatic inhibition previously proposed, except for 2´,4´-dihydroxy-3´-methoxychalcone - oxacillin. The best combination was 2´,3´-dihydroxychalcone - oxacillin (MIC: 11.2 μg/mL. Further investigations are needed to characterize the interaction mechanism with antibiotics. Thus, chalcones - oxacillin combination could lead to the development of new antibiotics against methicillin resistant S. aureus infection.

Transmission and persistence of livestock-associated methicillin-resistant Staphylococcus aureus among veterinarians and their household members

NARCIS (Netherlands)

Bosch, T; Verkade, E; van Luit, M; Landman, F; Kluytmans, J; Schouls, L M

After the first isolation of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in 2003, this MRSA variant quickly became the predominant MRSA obtained from humans as part of the Dutch national MRSA surveillance. Previous studies have suggested that human-to-human

Detection of methicillin resistance and slime factor production of Staphylococcus aureus in bovine mastitis Detecção de resistência a meticilina e produção do fator slime por Staphylococcus aureus em mastite bovina

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Alper Ciftci

2009-06-01

Full Text Available This study aimed to detect methicillin resistant and slime producing Staphylococcus aureus in cases of bovine mastitis. A triplex PCR was optimized targetting 16S rRNA, nuc and mecA genes for detection of Staphylococcus species, S. aureus and methicillin resistance, respectively. Furthermore, for detection of slime producing strains, a PCR assay targetting icaA and icaD genes was performed. In this study, 59 strains were detected as S. aureus by both conventional tests and PCR, and 13 of them were found to be methicillin resistant and 4 (30.7% were positive for mecA gene. Although 22 of 59 (37.2% S. aureus isolates were slime-producing in Congo Red Agar, in PCR analysis only 15 were positive for both icaA and icaD genes. Sixteen and 38 out of 59 strains were positive for icaA and icaD gene, respectively. Only 2 of 59 strains were positive for both methicillin resistance and slime producing, phenotypically, suggesting lack of correlation between methicillin resistance and slime production in these isolates. In conclusion, the optimized triplex PCR in this study was useful for rapid and reliable detection of methicillin resistant S. aureus. Furthermore, only PCR targetting icaA and icaD may not sufficient to detect slime production and further studies targetting other ica genes should be conducted for accurate evaluation of slime production characters of S. aureus strains.Este estudo objetivou a detecção de Staphylococcus aureus resistente a meticilina e produtor do fator slime em casos de mastite bovina. Um PCR triplex foi otimizado, com alvo no genes 16SrRNA, nuc e mecA para detecção de Staphylococcus spp, S. aureus e resistencia a meticilina, respectivamente. Para detecção das cepas produtoras do fator slime, empregou-se um PCR com alvo nos genes icaA e icaD. No estudo, 59 cepas foram identificadas como S. aureus por testes convencionais e PCR, sendo 13 resistentes a meticilina e quatro positivas para o gene mecA. Embora 22 das 59 cepas

Are Nasal Carriers of Staphylococcus aureus More Likely To Become Colonized or Infected with Methicillin-Resistant Staphylococcus aureus on Admission to a Hospital?▿

OpenAIRE

Krebes, Juliane; Al-Ghusein, Hasan; Feasey, Nick; Breathnach, Aodhan; Lindsay, Jodi A.

2010-01-01

Of 840 patients at hospital admission, 2.7% were positive for methicillin-resistant Staphylococcus aureus (MRSA) and 22.3% were positive for methicillin-susceptible S. aureus (MSSA). During the next 8 months, 4.8% of the MSSA-positive patients acquired MRSA with no lineage association. A total of 5.2% of noncarriers acquired MRSA. We find no evidence that colonized hosts are more susceptible to acquiring MRSA.

Microbiological evaluation of a new growth-based approach for rapid detection of methicillin-resistant Staphylococcus aureus

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von Eiff, Christof; Maas, Dominik; Sander, Gunnar; Friedrich, Alexander W; Peters, Georg; Becker, Karsten

OBJECTIVES: Recently, a rapid screening tool for methicillin-resistant Staphylococcus aureus (MRSA) has been introduced that applies a novel detection technology allowing the rapid presence or absence of MRSA to be determined from an enrichment broth after only a few hours of incubation. To evaluate

Antimicrobial activity of zinc and titanium dioxide nanoparticles against biofilm-producing methicillin-resistant Staphylococcus aureus

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Jesline, A.; John, Neetu P.; Narayanan, P. M.; Vani, C.; Murugan, Sevanan

2015-02-01

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the major nosocomial pathogens responsible for a wide spectrum of infections and the emergence of bacterial resistance to antibiotics has lead to treatment drawbacks towards large number of drugs. Formation of biofilms is the main contributing factor to antibiotic resistance. The development of reliable processes for the synthesis of zinc oxide nanoparticles is an important aspect of nanotechnology today. Zinc oxide and titanium dioxide nanoparticles comprise well-known inhibitory and bactericidal effects. Emergence of antimicrobial resistance by pathogenic bacteria is a major health problem in recent years. This study was designed to determine the efficacy of zinc and titanium dioxide nanoparticles against biofilm producing methicillin-resistant S. aureus. Biofilm production was detected by tissue culture plate method. Out of 30 MRSA isolates, 22 isolates showed strong biofilm production and 2 showed weak and moderate biofilm formation. Two strong and weak biofilm-producing methicillin-resistant S. aureus isolates were subjected to antimicrobial activity using commercially available zinc and titanium dioxide nanoparticles. Thus, the nanoparticles showed considerably good activity against the isolates, and it can be concluded that they may act as promising, antibacterial agents in the coming years.

Community-Associated Methicillin-Resistant Staphylococcus aureus Infections in Men Who Have Sex With Men: A Case Series

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R Sztramko

2007-01-01

Full Text Available BACKGROUND: The purpose of the present study was to describe the clinical characteristics and management of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA infections among a cohort of men who have sex with men.

Effect of neonatal malnutrition on expression of nitric oxide synthase enzyme, production of free radicals and in vitro viability of alveolar macrophages infected with methicillin-sensitive and methicillin-resistant Staphylococcus aureus.

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de Morais, Natália Gomes; da Costa, Thacianna Barreto; Pedrosa, Amanda Lúcia Farias; de Castro, Maria Carolina Accioly Brelaz; da Gonçalves de Albuquerque, Suênia Cunha; Pereira, Valéria Rêgo Alves; de Paiva Cavalcanti, Milena; de Castro, Célia Maria Machado Barbosa

2016-02-01

Evaluate the effects of neonatal malnutrition on the microbicidal response and viability of in vitro macrophages infected with Staphylococcus aureus sensitive/resistant to methicillin. Male Wistar rats (n = 24) were divided into two distinct groups: nourished (rats breast-fed by mothers undergoing diet with 17% casein) and malnourished (rats breast-fed by mothers undergoing diet with 8% casein). Macrophages were recovered after surgical tracheostomy procedure by collecting bronchoalveolar lavage. Four systems were established: negative control, composed only by phagocytes; positive control, macrophages plus lipopolysaccharide; and two test systems, macrophages plus Staphylococcus aureus sensitive and resistant to methicillin. Plates were incubated at 37 °C for 24 h. After this period, tests for the analysis of cell viability and microbicidal response were performed. In the statistical analysis, the Student's t and ANOVA tests were used, accepting p resistant Staphylococcus aureus. However, increased production of superoxide anion in the malnourished group was detected. Neonatal malnutrition focusing on critical periods of development promoted lower expression of iNOS, nitric oxide production, cell viability, and exacerbated reactive oxygen species production. The high levels of reactive oxygen species may favor the onset of serious and systemic infections with fatal outcome if associated with methicillin-resistant Staphylococcus aureus.

Comparison of antibiotic resistance, virulence gene profiles, and pathogenicity of methicillin-resistant and methicillin-susceptible Staphylococcus aureus using a Caenorhabditis elegans infection model

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Thompson, Terissa; Brown, Paul D

2014-01-01

Objectives: This study compared the presence of 35 virulence genes, resistance phenotypes to 11 anti-staphylococcal antibiotics, and pathogenicity in methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible S. aureus (MSSA). Methods: Multiplex PCR analysis was used to differentiate Staphylococcus aureus isolates (n = 102) based on characterization of the Staphylococcal Cassette Chromosome mec (SCCmec). Singleplex and multiplex PCR assays targeting 35 virulence determinants were used to analyze the virulence repertoire of S. aureus. In vitro activities of the antibiotics were determined by the disk-diffusion method. The pathogenicity of representative isolates was assessed using Caenorhabditis elegans survival assays. Significance in virulence distribution and antibiotic resistance phenotypes was assessed using the Chi-squared tests. Kaplan–Meier survival estimates were used to analyze nematode survival and significance of survival rates evaluated using the log-rank test. Results: Except for sei (staphylococcal enterotoxin I) (P  =  0.027), all other virulence genes were not significantly associated with MRSA. Resistance to clindamycin (P  =  0.03), tetracycline (P  =  0.048), trimethoprim/sulfamethoxazole (P  =  0.038), and oxacillin (P  =  0.004) was significantly associated with MRSA. Survival assay showed MSSA having a lower median lifespan of 3 days than MRSA that had a median lifespan of 6 days. The difference in the killing time of MRSA and MSSA was significant (P virulence genes. The quicker killing potential of MSSA compared to MRSA suggests that carriage of virulence determinants per se does not determine pathogenicity in S. aureus. Pathogenicity is impacted by other factors, possibly antibiotic resistance. PMID:25319852

Methicillin-resistant staphylococci in animals: epidemiology and interventions

NARCIS (Netherlands)

Verstappen, K.M.H.W.|info:eu-repo/dai/nl/357079485

2017-01-01

Antimicrobial resistance in bacteria is a global problem. Important organisms are methicillin-resistant Staphylococcus aureus (MRSA), which is widespread among pigs, and Staphylococcus pseudintermedius (MRSP), which is an important pathogen in dogs and cats. Infections with these organisms can be

Hospital-Acquired Methicillin-resistant Staphylococcus aureus Bacteremia Related to Medicare Antibiotic Prescriptions: A State-Level Analysis.

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Fukunaga, Bryce T; Sumida, Wesley K; Taira, Deborah A; Davis, James W; Seto, Todd B

2016-10-01

Methicillin-resistant Staphylococcus aureus (MRSA) results in almost half of all deaths caused by antibiotic resistant organisms. Current evidence suggests that MRSA infections are associated with antibiotic use. This study examined state-level data to determine whether outpatient antibiotic use was associated with hospital-acquired MRSA (HA-MRSA) infections. The 2013 Centers for Disease Control and Prevention (CDC) Healthcare-Associated Infections Progress Report was used to obtain HA-MRSA infection rates. Data on the number of antibiotic prescriptions with activity towards methicillin-sensitive Staphylococcus aureus (MSSA) at the state level were obtained from the 2013 Medicare Provider Utilization and Payment Data: Part D Prescriber Public Use File. Pearson's correlation coefficient was used to analyze the relationship between the number of antibiotic prescriptions and HA-MRSA infection rates. The average number of HA-MRSA infections was 0.026 per 1000 persons with the highest rates concentrated in Southeastern and Northeastern states. The average number of outpatient prescriptions per capita was 0.74 with the highest rates in Southeastern states. A significant correlation (ρ = 0.64, P resistance.

A new multiplex PCR for easy screening of methicillin-resistant Staphylococcus aureus SCCmec types I-V

DEFF Research Database (Denmark)

Boye, Kit; Bartels, Mette Damkjær; Andersen, Ina S

2007-01-01

A multiplex PCR with four primer-pairs was designed to identify the five main known SCCmec types. A clear and easily discriminated band pattern was obtained for all five types. The SCCmec type was identified for 98% of 312 clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA...

Improved understanding of factors driving methicillin-resistant Staphylococcus aureus epidemic waves

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Chatterjee, Som S; Otto, Michael

2013-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) remains one of the most important causes of nosocomial infections worldwide. Since the global spread of MRSA in the 1960s, MRSA strains have evolved with increased pathogenic potential. Notably, some strains are now capable of causing persistent infections not only in hospitalized patients but also in healthy individuals in the community. Furthermore, MRSA is increasingly associated with infections among livestock-associated workers, primarily because of transmission from animals to humans. Moreover, many MRSA strains have gained resistance to most available antibiotics. In this review, we will present current knowledge on MRSA epidemiology and discuss new endeavors being undertaken to understand better the molecular and epidemiological underpinnings of MRSA outbreaks. PMID:23861600

Rapid identification of Staphylococcus aureus and methicillin resistance by flow cytometry using a peptide nucleic acid probe.

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Shrestha, Nabin K; Scalera, Nikole M; Wilson, Deborah A; Brehm-Stecher, Byron; Procop, Gary W

2011-09-01

A total of 56 Staphylococcus aureus isolates incubated for 2 h in the presence or absence of oxacillin were analyzed by flow cytometry after labeling with an S. aureus-specific peptide nucleic acid (PNA) probe. Two defined ratios, the paired signal count ratio (PSCR) and the gate signal count ratio (GSCR), differentiated methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) with sensitivities of 100% each and specificities of 96% and 100%, respectively.

Prevalence and antimicrobial susceptibility pattern of methicillin resistant Staphylococcus aureus isolates from Trinidad & Tobago

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Monteil Michele

2006-07-01

Full Text Available Abstract Background Methicillin-resistant Staphylococcus aureus (MRSA has become increasingly prevalent worldwide since it was first reported in a British hospital. The prevalence however, varies markedly in hospitals in the same country, and from one country to another. We therefore sought to document comprehensively the prevalence and antimicrobial susceptibility pattern of MRSA isolates in Trinidad and Tobago. Methods All Staphylococcus aureus isolates encountered in routine clinical specimens received at major hospitals in the country between 2000 and 2001 were identified morphologically and biochemically by standard laboratory procedures including latex agglutination test (Staphaurex Plus; Murex Diagnostics Ltd; Dartford, England; tube coagulase test with rabbit plasma (Becton, Dickinson & Co; Sparks, MD, USA, and DNase test using DNase agar (Oxoid Ltd; Basingstoke, Hampshire, England. MRSA screening was performed using Mueller-Hinton agar containing 6 μg oxacillin and 4% NaCl, latex agglutination test (Denka Seiken Co. Ltd, Tokyo, Japan and E-test system (AB Biodisk, Solna, Sweden. Susceptibility to antimicrobial agents was determined by the modified Kirby Bauer disc diffusion method while methicillin MICs were determined with E-test system. Results Of 1,912 S. aureus isolates received, 12.8% were methicillin (oxacillin resistant. Majority of the isolates were recovered from wound swabs (86.9% and the least in urine (0.4% specimens. Highest number of isolates was encountered in the surgical (62.3% and the least from obstetrics and gynaecology (1.6% facilities respectively. Large proportions of methicillin sensitive isolates are >85% sensitive to commonly used and available antimicrobials in the country. All MRSA isolates were resistant to ceftriaxone, erythromycin, gentamicin and penicillin but were 100% sensitive to vancomycin, rifampin and chloramphenicol. Conclusion There is a progressive increase in MRSA prevalence in the country but

Staphylococcal scalded skin syndrome in a premature newborn caused by methicillin-resistant Staphylococcus aureus: case report

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Andreas Hörner

Full Text Available CONTEXT: Staphylococcal scalded skin syndrome is an exfoliative skin disease. Reports of this syndrome in newborns caused by methicillin-resistant Staphylococcus aureus are rare but, when present, rapid diagnosis and treatment is required in order to decrease morbidity and mortality. CASE REPORT: A premature newly born girl weighing 1,520 g, born with a gestational age of 29 weeks and 4 days, developed staphylococcal scalded skin syndrome on the fifth day of life. Cultures on blood samples collected on the first and fourth days were negative, but Pseudomonas aeruginosa and Enterococcus sp. (vancomycin-sensitive developed in blood cultures performed on the day of death (seventh day, and Pseudomonas aeruginosa and Serratia marcescens were identified in cultures on nasopharyngeal, buttock and abdominal secretions. In addition to these two Gram-negative bacilli, methicillin-resistant Staphylococcus aureus was isolated in a culture on the umbilical stump (seventh day. The diagnosis of staphylococcal scalded skin syndrome was based on clinical criteria.

Community-Associated Methicillin-Resistant Staphylococcus aureus in a Pediatric Emergency Department in Newfoundland and Labrador

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Erin Peebles

2014-01-01

Full Text Available BACKGROUND: First-generation cephalosporins and antistaphylococcal penicillins are typically the first choice for treating skin and soft tissue infections (SSTI, but are not effective for infections caused by methicillin-resistant Staphylococcus aureus (MRSA. It is currently unclear what percentage of SSTIs is caused by community-associated MRSA in different regions in Canada.

Prevalence and antimicrobial susceptibility pattern of methicillin resistant Staphylococcus aureus: A multicentre study.

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Rajaduraipandi K

2006-01-01

Full Text Available Purpose: Methicillin resistant Staphylococcus aureus (MRSA is an important nosocomial pathogen. We report the prevalence and antibiotic susceptibility pattern of MRSA in major southern districts of Tamilnadu. Methods: A total of 7172 clinical specimens and 1725 carrier screening samples were collected from different centers and subjected to MRSA screening using conventional microbiological methods. Subsequently the antibiotic sensitivity test was performed for the confirmed MRSA isolates. Results: Out of 906 strains of S. aureus isolated from clinical and carrier samples, 250 (31.1% and 39 (37.9% were found to be methicillin resistant respectively. Almost all clinical MRSA strains (99.6% were resistant to penicillin, 93.6% to ampicillin, and 63.2% towards gentamicin, co-trimoxazole, cephalexin, erythromycin, and cephotaxime. All MRSA strains (100% of carrier screening samples had resistance to penicillin and about 71.8% and 35.9% were resistant to ampicillin and co-trimoxazole respectively. Multidrug resistance was observed among 63.6% of clinical and 23% of carrier MRSA isolates. However, all strains of clinical and carrier subjects were sensitive to vancomycin. Conclusion: The determination of prevalence and antibiotic sensitivity pattern of MRSA will help the treating clinicians for first line treatment in referral hospitals.

Methicillin-susceptible and -resistant Staphylococcus aureus with high-level antiseptic and low-level mupirocin resistance in Malaysia.

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Ghasemzadeh-Moghaddam, Hamed; van Belkum, Alex; Hamat, Rukman Awang; van Wamel, Willem; Neela, Vasanthakumari

2014-10-01

The prevalence and spread of mupirocin and antiseptic resistance among colonizing and infectious Staphylococcus aureus were determined. S. aureus isolated from anterior nares and infection sites of patients hospitalized in the largest tertiary care referral hospital in Malaysia was investigated for mupirocin and antiseptic susceptibility testing, and for PCR detection of mupA, qacA/B, and smr genes. Twelve isolates showed resistance to mupirocin by disk diffusion, of which 10 (3.8%) harbored the mupA gene. Minimum inhibitory concentrations (MICs) ranged from 64 to 768 μg/ml for mupA positive and below 46 μg/ml for negative isolates. The mupA was more common among ST239 isolates (70%). The qacA/B was carried in 67 out of 95 methicillin-resistant Staphylococcus aureus (MRSA) (70.5%) and 3 out of 164 methicillin-susceptible Staphylococcus aureus (MSSA) (1.8%), while smr was carried in 6 out of 95 MRSA (6.3%) strains. MICs ranged from 3.9 to 15.6 μg/ml for benzethonium chloride (BTC) and benzalkonium chloride (BKC), and from 10.3 to 20.7 μg/ml for chlorhexidine digluconate (CHG). Isolates with qacA/B and smr or qacA/B alone showed higher MIC (20.7 μg/ml for CHG and 15.6 μg/ml for BTC and BKC) than the isolates that lacked antiseptic resistance genes (10.3 μg/ml for CHG and 3.9 μg/ml for BTC and BKC). In 16 cases, ST239 was isolated from the infection site and the nares simultaneously, and shared identical resistance patterns (qacAB or qacAB+smr), suggesting possible endogenous infection. Spread of low-level mupirocin resistance expressing ST239 MRSA and high-level resistance expressing emerging ST1, co-existing with antiseptic-resistant genes showing elevated MICs, should be monitored for effective infection control.

Rapid screening of pyogenic Staphylococcus aureus for confirmation of genus and species, methicillin resistance and virulence factors by using two novel multiplex PCR.

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Haque, Abdul; Haque, Asma; Saeed, Muhammad; Azhar, Aysha; Rasool, Samreen; Shan, Sidra; Ehsan, Beenish; Nisar, Zohaib

2017-01-01

Emergence of methicillin resistant Staphylococcus aureus (MRSA) is a major medical problem of current era. These bacteria are resistant to most drugs and rapid diagnosis can provide a clear guideline to clinicians. They possess specific virulence factors and relevant information can be very useful. We designed this study to develop multiplex PCRs to provide rapid information. We studied 60 Staphylococcus aureus isolates and detected methicillin resistance by cefoxitin sensitivity and targeting of mecA gene. After initial studies with uniplex PCRs we optimized two multiplex PCRs with highly reproducible results. The first multiplex PCR was developed to confirm genus, species and methicillin resistance simultaneously, and the second multiplex PCR was for screening of virulence factors. We found 38.33% isolates as methicillin resistant. α -toxin, the major cytotoxic factor, was detected in 40% whereas β-hemolysin was found in 25% cases. Panton Valentine leucocidin was detected in 8.33% and toxic shock syndrome toxin in5% cases. The results of uniplex and multiplex PCRs were highly compatible. These two multiplex PCRs when run simultaneously can provide vital information about methicillin resistance and virulence status of the isolate within a few hours as compared to several days needed by routine procedures.

Methicillin-Resistant Staphylococcus aureus (MRSA Detection from the Hands of Jatinangor Community Health Center’s Health Care Providers

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Jeevanisha Patmanathan

2015-06-01

Full Text Available Background: Methicillin-resistant Staphylococcus aureus is a bacterium that is resistance towards β-lactam antibiotics, and it seems to be one of the leading causes of nosocomial infections. Hands of the health care workers are said to be the main source for the nosocomial transmission. Thus, the study aims to determine methicillin-resistant S. aureus from the hands of Jatinangor Community Health Center’s health care workers. Methods: Samples were taken from the hands of 30 Jatinangor Community Health Center’s staffs, including medical and paramedical; from October 2012 to November 2012. Then, these samples underwent further laboratory examinations, starting from culture, identification and susceptibility test towards cefoxitin, in identifying methicillin-resistant S. aureus. Results: Out of the 30 samples taken, 6 samples (20% were positive for S. aureus isolates. In which, 4 (13.33% of the samples were positive for methicillin-resistant S. aureus. Conclusions: Since, health care workers are the main people in contact with patients and maintaining proper hand hygiene makes a huge difference; hand hygiene should be given adequate attention for the benefit of all.

Comparison of Biofilm Formation between Methicillin-Resistant and Methicillin-Susceptible Isolates of Staphylococcus aureus.

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Ghasemian, Abdolmajid; Najar Peerayeh, Shahin; Bakhshi, Bita; Mirzaee, Mohsen

2016-07-01

The aim of this study was to compare the biofilm formation and the prevalence of biofilm-associated genes between the isolates of methicillin-resistant (MRSA) and methicillin-susceptible (MSSA) Staphylococcus aureus. In total, 209 S. aureus isolates were collected. The antibiotic susceptibility test was conducted using nine antibiotics according to the guidelines of Clinical and Laboratory Standards Institute. Phenotypic biofilm formation was performed with microtiter plate assay. The polymerase chain reaction was employed to detect icaA, icaD, icaB, icaC, clfA, clfB, fnbA, fnbB, fib, cna, eno, ebps, bbp, mecA, and SCCmec types as well as agr group genes with specific primers. Sixty-four (30.62%) isolates were resistant to methicillin, and 54 (83%) MRSA harbored SCCmec III. Furthermore, 122 (58.3%) isolates belonged to agr group I. Twenty-six (36.1%) MRSA and 42 (28.9%) MSSA isolates were strong biofilm producers (no significant difference). The prevalence of icaA, icaD, icaB, and icaC genes in MSSA isolates was 71, 41, 76, and 72%, respectively. The frequency of clfA, clfB, fnbA, fnbB, fib, cna, eno, ebps, and bbp in MSSA was 100, 100, 56, 46, 74, 54, 78, 11, and 1%, respectively. However, in MRSA isolates, the frequency was 97, 97, 64, 51, 76, 56, 79, and 12% with no track of bbp, respectively. Statistical difference between MSSA and MRSA regarding biofilm formation and the frequency of all biofilm-encoding genes was not significant. The majority of the S. aureus isolates harbored clfA, clfB, eno, fib, icaA, and icaD genes.

Design of two molecular methodologies for the rapid identification of Colombian community-acquired methicillin-resistant Staphylococcus aureus isolates

OpenAIRE

Escobar, Javier Antonio; Gómez, Ingrid Tatiana; Murillo, Martha Johanna; Castro, Betsy Esperanza; Chavarro, Bibiana; Márquez, Ricaurte Alejandro; Vanegas, Natasha

2012-01-01

Introduction. Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections are found with increasing the frequency, both in healthy individuals in the community and in hospitalized patients. In Colombia and the Andean region, CA-MRSA isolates have a genetic background that is related to the pandemic USA300 clone. Objective. Two molecular methods are designed and standardized for the rapid differentiation of Colombian community-acquired and hospital-acquired methicillin-...

Recommendations for Methicillin-Resistant Staphylococcus aureus Prevention in Adult ICUs: A Cost-Effectiveness Analysis.

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Whittington, Melanie D; Atherly, Adam J; Curtis, Donna J; Lindrooth, Richard C; Bradley, Cathy J; Campbell, Jonathan D

2017-08-01

Patients in the ICU are at the greatest risk of contracting healthcare-associated infections like methicillin-resistant Staphylococcus aureus. This study calculates the cost-effectiveness of methicillin-resistant S aureus prevention strategies and recommends specific strategies based on screening test implementation. A cost-effectiveness analysis using a Markov model from the hospital perspective was conducted to determine if the implementation costs of methicillin-resistant S aureus prevention strategies are justified by associated reductions in methicillin-resistant S aureus infections and improvements in quality-adjusted life years. Univariate and probabilistic sensitivity analyses determined the influence of input variation on the cost-effectiveness. ICU. Hypothetical cohort of adults admitted to the ICU. Three prevention strategies were evaluated, including universal decolonization, targeted decolonization, and screening and isolation. Because prevention strategies have a screening component, the screening test in the model was varied to reflect commonly used screening test categories, including conventional culture, chromogenic agar, and polymerase chain reaction. Universal and targeted decolonization are less costly and more effective than screening and isolation. This is consistent for all screening tests. When compared with targeted decolonization, universal decolonization is cost-saving to cost-effective, with maximum cost savings occurring when a hospital uses more expensive screening tests like polymerase chain reaction. Results were robust to sensitivity analyses. As compared with screening and isolation, the current standard practice in ICUs, targeted decolonization, and universal decolonization are less costly and more effective. This supports updating the standard practice to a decolonization approach.

Treatment of methicillin-resistant Staphylococcus aureus in Latin America Tratamento de Staphylococcus aureus resistente à meticilina na América Latina

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Carlos M Luna

2010-12-01

Full Text Available The global spread of methicillin-resistant Staphylococcus aureus (MRSA means it is now a pathogen of worldwide public health concern. Within Latin America, MRSA is highly prevalent, with the proportion of S. aureus isolates that are methicillin-resistant on the rise, yet resources for managing the infection are limited. While several guidelines exist for the treatment of MRSA infections, many are written for the North American or European setting and need adaptation for use in Latin America. In this article, we aim to emphasize the importance of appropriate treatment of MRSA in the healthcare and community settings of Latin America. We present a summary of the available guidelines and antibiotics, and discuss particular considerations for clinicians treating MRSA in Latin AmericaA propagação global de Staphylococcus aureus resistente à meticilina (methicillin-resistant Staphylococcus aureus - MRSA significa que se trata agora de um patógeno de interesse para a saúde pública mundial. Na América Latina, o MRSA é altamente prevalente, com a proporção de S. aureus resistente à meticilina em ascensão, no entanto os recursos para o tratamento da infecção são limitados. Embora existam várias diretrizes para o tratamento de infecções por MRSA, muitas são elaboradas para a América do Norte ou a Europa e precisam ser adaptadas para sua utilização na América Latina. Neste artigo, procuramos destacar a importância do tratamento adequado do MRSA nas unidades de saúde e na comunidade na América Latina. Apresentamos um resumo das diretrizes e dos antibióticos disponíveis, e discutimos considerações específicas para os médicos que tratam de MRSA na América Latina.

Methicillin-resistant Staphylococcus aureus containing mecC in Swedish dairy cows

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Unnerstad Helle Ericsson

2013-01-01

Full Text Available Abstract Background Hitherto, methicillin-resistant Staphylococcus aureus (MRSA has not been detected in Swedish cattle. However, due to the report of mecC, a novel homologue to the mecA gene, there was reason to re-evaluate susceptibility results from strain collections of Staphylococcus aureus and test suspected isolates for the presence of mecC. Findings Bovine isolates of S. aureus with elevated minimum inhibitory concentrations of beta-lactams were retrospectively tested for presence of mecC. In four of the isolates mecC was detected. Conclusion In Sweden, this is the first finding of MRSA in cattle and the first detection of MRSA harbouring mecC of domestic animal origin. MRSA in animal populations has implications as a potential reservoir with risk for spread to humans. Occurrence of MRSA among Swedish cattle appears still very limited.

rRNA Operon Copy Number Can Explain the Distinct Epidemiology of Hospital-Associated Methicillin-Resistant Staphylococcus aureus

NARCIS (Netherlands)

Fluit, A.C.; Jansen, M.D.; Bosch, T.; Jansen, W.T.M.; Schouls, L.; Jonker, M.J.; Boel, C.H.E.

2016-01-01

The distinct epidemiology of original hospital-associated methicillin-resistant Staphylococcus aureus (HA-MRSA) and early community-associated MRSA (CA-MRSA) is largely unexplained. S. aureus carries either five or six rRNA operon copies. Evidence is provided for a scenario in which MRSA has adapted

Population-Based Estimates of Methicillin-Resistant "Staphylococcus aureus" (MRSA) Infections among High School Athletes--Nebraska, 2006-2008

Science.gov (United States)

Buss, Bryan F.; Mueller, Shawn W.; Theis, Max; Keyser, Alison; Safranek, Thomas J.

2009-01-01

Methicillin-resistant "Staphylococcus aureus" (MRSA) is an emerging cause of skin and soft-tissue infections among athletes. To determine statewide incidence among high school athletes, we surveyed all 312 Nebraska high schools regarding sport programs offered, program-specific participation numbers, number of athletes with…

High Rate of qacA- and qacB-Positive Methicillin-Resistant Staphylococcus aureus Isolates from Chlorhexidine-Impregnated Catheter-Related Bloodstream Infections

OpenAIRE

Ho, Cheng-Mao; Li, Chi-Yuan; Ho, Mao-Wang; Lin, Chien-Yu; Liu, Shu-Hui; Lu, Jang-Jih

2012-01-01

Chlorhexidine has been widely used for infection control. Although the use of chlorhexidine-impregnated catheters has reduced catheter-related infections, chlorhexidine-resistant Staphylococcus aureus has emerged. The correlation between the existence of the chlorhexidine-resistant genes qacA and qacB (qacA/B) in methicillin-resistant Staphylococcus aureus (MRSA) isolates and the effectiveness of chlorhexidine-impregnated catheters in the prevention of MRSA infections is unknown. Sixty methic...

Presence of antiseptic resistance genes in porcine methicillin-resistant Staphylococcus aureus.

Science.gov (United States)

Wong, T Z; Zhang, M; O'Donoghue, M; Boost, M

2013-03-23

Numerous studies have documented the presence of methicillin-resistant Staphylococcus aureus (MRSA) in meat-producing animals, which has led to concern about its spread into the community. Disinfectants play an important role in reduction of contamination in both animal husbandry and food-preparation, helping control spread of organisms from foodstuffs, including raw meat. Plasmid-borne antiseptic resistance (AR) genes increasing tolerance to several disinfectants have been reported in S. aureus of human origin (qacA/B and smr) and from bovine, equine, and caprine staphylococcal isolates (qacG, qacH, and qacJ). This study investigated the presence of AR genes in porcine MRSA isolates. Plasmid DNA from 100 MRSA ST9 strains isolated from pig carcasses was amplified for the presence of AR genes. Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) to benzalkonium chloride (BC) and chlorhexidine gluconate (CHX) were determined in AR gene-positive isolates. qacG was present in 45 strains, eight of which also harbored smr. No strains carried qacA/B, qacH or qacJ. Presence of smr increased MICs to both BC and CHX and MBCs of CHX, but qacG presence only resulted in elevated MBC for CHX. This is the first report of AR genes from a porcine source. AR gene positivity has previously been associated with methicillin resistance and AR gene presence in these strains may increase their ability to persist in the environment. Improved implementation of hygiene measures during transportation and pre- and post-slaughter should be considered to prevent spread in the community. Copyright © 2012 Elsevier B.V. All rights reserved.

Misidentification of methicillin-resistant Staphylococcus aureus (MRSA) in hospitals in Tripoli, Libya

Science.gov (United States)

Ahmed, Mohamed O.; Abuzweda, Abdulbaset R.; Alghazali, Mohamed H.; Elramalli, Asma K.; Amri, Samira G.; Aghila, Ezzeddin Sh.; Abouzeed, Yousef M.

2010-01-01

Background Methicillin-resistant Staphylococcus aureus (MRSA) is a nosocomial (hospital-acquired) pathogen of exceptional concern. It is responsible for life-threatening infections in both the hospital and the community. Aims To determine the frequency of MRSA misidentification in hospitals in Tripoli, Libya using current testing methods. Methods One hundred and seventy S. aureus isolates previously identified as MRSA were obtained from three hospitals in Tripoli. All isolates were reidentified by culturing on mannitol salt agar, API 20 Staph System and retested for resistance to methicillin using the cefoxitin disk diffusion susceptibility test and PBP2a. D-tests and vancomycin E-tests (Van-E-tests) were also performed for vancomycin-resistant isolates. Results Of the 170 isolates examined, 86 (51%) were confirmed as MRSA (i.e. 49% were misidentified as MRSA). Fifteen (17%) of the confirmed MRSA strains exhibited inducible clindamycin resistance. Of the 86 confirmed MRSA isolates, 13 (15%) were resistant to mupirocin, 53 (62%) were resistant to ciprofloxacin, 41 (48%) were resistant to trimethoprim-sulfamethoxazole, and none were resistant to linezolid. Although disc-diffusion testing indicated that 23 (27%) of the isolates were resistant to vancomycin, none of the isolates were vancomycin-resistant by Van-E-test. Conclusions Misidentification of nosocomial S. aureus as MRSA is a serious problem in Libyan hospitals. There is an urgent need for the proper training of microbiology laboratory technicians in standard antimicrobial susceptibility procedures and the implementation of quality control programs in microbiology laboratories of Libyan hospitals. PMID:21483574

Prospective Study of Infection, Colonization and Carriage of Methicillin-Resistant Staphylococcus Aureus in an Outbreak Affecting 990 Patients

NARCIS (Netherlands)

R. Coello; J. Jimenez (Jose); M. Garcia (Melissa); P. Arroyo; D. Minguez; C. Fernandez; F. Cruzet; C. Gaspar

1994-01-01

textabstractIn the three years between November 1989 and October 1992, an outbreak of methicillin-resistantStaphylococcus aureus (MRSA) affected 990 patients at a university hospital. The distribution of patients with carriage, colonization or infection was investigated prospectively. Nosocomial

Evaluation of different methods to detect methicillin resistance in Staphylococcus aureus (MRSA).

Science.gov (United States)

Alipour, Farzad; Ahmadi, Malahat; Javadi, Shahram

2014-01-01

The studies suggest that dogs living with human are potential risk of becoming MRSA carrier and increased risk of infections caused by MRSA. Phenotypic methods to detect methicillin resistance in Staphylococcus aureus (MRSA) are inadequate. The objective of the present study was to determine methicillin resistance in S. aureus by phenotypic susceptibility test (oxacillin disk diffusion, cefoxitin disk diffusion, oxacillin screen agar) and molecular methods (PCR as a gold standard) and the latex agglutination test for the detection of PBP2a and to evaluate the results of these tests for its sensitivity and specificity. A total of 100 swab samples were taken from muzzle site, in more contact with human, of dogs and MRSA were isolated. Oxacillin (1 μg), cefoxitin (30 μg) disk diffusion and oxacillin screen agar method were used. The isolates were also subjected to latex agglutination test for detection of PBP2a and PCR to detect mecA gene. By PCR 37% of isolates show the presence of mecA. Latex agglutination was found to be the most sensitive (97.29%) and cefoxitin disk diffusion to be the most specific (96.82%) tests for detection of MRSA. Our finding showed that combining oxacillin screen agar or cefoxitin disk diffusion with latex agglutination improves sensitivity and specificity to detect methicillin resistance S. aureus (MRSA) isolates. Copyright © 2014 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

Genotypic and Phenotypic Markers of Livestock-Associated Methicillin-Resistant Staphylococcus aureus CC9 in Humans

OpenAIRE

Ye, Xiaohua; Wang, Xiaolin; Fan, Yanping; Peng, Yang; Li, Ling; Li, Shunming; Huang, Jingya; Yao, Zhenjiang; Chen, Sidong

2016-01-01

Use of antimicrobials in industrial food animal production is associated with the presence of multidrug-resistant Staphylococcus aureus among animals and humans. The livestock-associated (LA) methicillin-resistant S. aureus (MRSA) clonal complex 9 (CC9) is associated with animals and related workers in Asia. This study aimed to explore the genotypic and phenotypic markers of LA-MRSA CC9 in humans. We conducted a cross-sectional study of livestock workers and controls in Guangdong, China. The ...

Personal hygiene and methicillin-resistant Staphylococcus aureus infection.

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Turabelidze, George; Lin, Mei; Wolkoff, Barbara; Dodson, Douglas; Gladbach, Stephen; Zhu, Bao-Ping

2006-03-01

Methicillin-resistant Staphylococcus aureus (MRSA) infections outside the healthcare setting are an increasing concern. We conducted a case-control study to investigate an MRSA outbreak during 2002-2003 in a Missouri prison and focused on hygiene factors. Information on sociodemographic characteristics, medical history, and hygiene practices of study participants was collected by interview and medical record review. Logistic regression was used to evaluate MRSA infection in relation to hygiene factors individually and as a composite hygiene score; potential confounding factors were controlled. Selected MRSA isolates were analyzed by pulsed-field gel electrophoresis (PFGE). MRSA infection was significantly associated with a low composite hygiene score. Transmission among prison inmates appeared to be responsible for this outbreak. PFGE analysis showed that isolates were indistinguishable and associated with community-onset MRSA infections in other US prisons. Improving hygiene practices and environmental conditions may help prevent and interrupt future MRSA outbreaks in prison settings.

The value of nasal mupirocin in containing an outbreak of methicillin- resistant Staphylococcus aureus in an orthopaedic unit

NARCIS (Netherlands)

S.P. Barrett

1990-01-01

textabstractAn outbreak of methicillin-resistant Staphylococcus aureus (MRSA) occurred in two adjacent orthopaedic wards following the admission of a known carrier. The outbreak was not contained by ward closure or by standard infection control measures. Eventually several nasal carriers were

DNA microarray genotyping and virulence and antimicrobial resistance gene profiling of methicillin-resistant Staphylococcus aureus bloodstream isolates from renal patients.

LENUS (Irish Health Repository)

McNicholas, Sinead

2012-02-01

Thirty-six methicillin-resistant Staphylococcus aureus (MRSA) bloodstream isolates from renal patients were genetically characterized by DNA microarray analysis and spa typing. The isolates were highly clonal, belonging mainly to ST22-MRSA-IV. The immune evasion and enterotoxin gene clusters were found in 29\\/36 (80%) and 33\\/36 (92%) isolates, respectively.

DNA microarray genotyping and virulence and antimicrobial resistance gene profiling of methicillin-resistant Staphylococcus aureus bloodstream isolates from renal patients.

LENUS (Irish Health Repository)

McNicholas, Sinead

2011-12-01

Thirty-six methicillin-resistant Staphylococcus aureus (MRSA) bloodstream isolates from renal patients were genetically characterized by DNA microarray analysis and spa typing. The isolates were highly clonal, belonging mainly to ST22-MRSA-IV. The immune evasion and enterotoxin gene clusters were found in 29\\/36 (80%) and 33\\/36 (92%) isolates, respectively.

High frequency of methicillin-susceptible and methicillin-resistant Staphylococcus aureus in children under 1 year old with skin and soft tissue infections.

Science.gov (United States)

Salazar-Ospina, Lorena; Jiménez, Judy Natalia

2017-09-21

Staphylococcus aureus is responsible for a large number of infections in pediatric population; however, information about the behavior of such infections in this population is limited. The aim of the study was to describe the clinical, epidemiological, and molecular characteristics of infections caused by methicillin-susceptible and resistant S. aureus (MSSA-MRSA) in a pediatric population. A cross-sectional descriptive study in patients from birth to 14 years of age from three high-complexity institutions was conducted (2008-2010). All patients infected with methicillin-resistant S. aureus and a representative sample of patients infected with methicillin-susceptible S. aureus were included. Clinical and epidemiological information was obtained from medical records and molecular characterization included spa typing, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST). In addition, staphylococcal cassette chromosome mec (SCCmec) and virulence factor genes were detected. A total of 182 patients, 65 with methicillin-susceptible S. aureus infections and 117 with methicillin-resistant S. aureus infections, were included in the study; 41.4% of the patients being under 1 year. The most frequent infections were of the skin and soft tissues. Backgrounds such as having stayed in day care centers and previous use of antibiotics were more common in patients with methicillin-resistant S. aureus infections (p≤0.05). Sixteen clonal complexes were identified and methicillin-susceptible S. aureus strains were more diverse. The most common cassette was staphylococcal cassette chromosomemec IVc (70.8%), which was linked to Panton-Valentine leukocidin (pvl). In contrast with other locations, a prevalence of infections in children under 1 year of age in the city could be observed; this emphasizes the importance of epidemiological knowledge at the local level. Copyright © 2017 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights

Fluoroquinolone susceptibilities to methicillin-resistant and susceptible coagulase-negative Staphylococcus isolated from eye infection Suscetibilidade dos Staphylococcus coagulase negativo meticilina-resistentes e suscetíveis isolados em infecções oculares

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Adália Dias Dourado Oliveira

2007-03-01

Full Text Available PURPOSE: To evaluate the fluoroquinolone susceptibilities of ocular isolate coagulase-negative staphylococci (CoNS, identified at the Microbiology Laboratory - UNIFESP. DESIGN: Experimental laboratory investigation. METHODS: The minimum inhibitory concentrations (MICs of 21 strains of methicillin-resistant coagulase-negative staphylococci (MRCoNS and 22 methicillin-sensitive coagulase-negative staphylococci (MSCoNS to ciprofloxacin, ofloxacin, gatifloxacin and moxifloxacin were determined, using the E-test method standardized by the Clinical and Laboratory Standards Institute (CLSI/NCCLS. RESULTS: The MIC90s (µg/ml for the second generation of tested fluoroquinolones were higher than the fourth generation, especially for the methicillin-resistant coagulase-negative staphylococci group. CONCLUSION: Our results indicate that methicillin-sensitive coagulase-negative staphylococci are more susceptible to quinolones than are methicillin-resistant coagulase-negative staphylococci and that fourth generation fluoroquinolones appear to be more potent, affecting even coagulase-negative staphylococcal strains resistant to second generation fluoroquinolones.OBJETIVOS: Avaliar a suscetibilidade a fluorquinolonas dos Staphylococcus coagulase-negativo (SCoN identificados no Laboratório de Microbiologia Ocular da Unifesp. MÉTODOS: Foi determinada a concentração inibitória mínima de 21 cepas de SCoN meticilina-resistentes e 22 meticilina-sensíveis para ciprofloxacina, ofloxacina, gatifloxacina e moxifloxacina, utilizando o E-test estandartizado pelo CLSI/NCCLS. RESULTADOS: Os MIC90 (µg/ml de 43 SCoN isolados para fluorquinolonas de segunda geração foram maiores do que os de quarta geração, principalmente para o grupo dos meticilina-resistentes. CONCLUSÃO: Nossos resultados indicam que Staphylococcus coagulase-negativo meticilina-sensíveis são mais suscetíveis às quinolonas do que os Staphylococcus coagulase-negativo meticilina

Mechanisms of methicillin-resistant Staphylococcus aureus pneumonia-induced intestinal epithelial apoptosis.

Science.gov (United States)

Perrone, Erin E; Jung, Enjae; Breed, Elise; Dominguez, Jessica A; Liang, Zhe; Clark, Andrew T; Dunne, W Michael; Burd, Eileen M; Coopersmith, Craig M

2012-07-01

Methicillin-resistant Staphylococcus aureus (MRSA) pneumonia-induced sepsis is a common cause of morbidity in the intensive care unit. Although pneumonia is initiated in the lungs, extrapulmonary manifestations occur commonly. In light of the key role the intestine plays in the pathophysiology of sepsis, we sought to determine whether MRSA pneumonia induces intestinal injury. FVB/N mice were subjected to MRSA or sham pneumonia and killed 24 h later. Septic animals had a marked increase in intestinal epithelial apoptosis by both hematoxylin-eosin and active caspase 3 staining. Methicillin-resistant S. aureus-induced intestinal apoptosis was associated with an increase in the expression of the proapoptotic proteins Bid and Bax and the antiapoptotic protein Bcl-xL in the mitochondrial pathway. In the receptor-mediated pathway, MRSA pneumonia induced an increase in Fas ligand but decreased protein levels of Fas, FADD, pFADD, TNF-R1, and TRADD. To assess the functional significance of these changes, MRSA pneumonia was induced in mice with genetic manipulations in proteins in either the mitochondrial or receptor-mediated pathways. Both Bid-/- mice and animals with intestine-specific overexpression of Bcl-2 had decreased intestinal apoptosis compared with wild-type animals. In contrast, Fas ligand-/- mice had no alterations in apoptosis. To determine if these findings were organism-specific, similar experiments were performed in mice subjected to Pseudomonas aeruginosa pneumonia. Pseudomonas aeruginosa induced gut apoptosis, but unlike MRSA, this was associated with increased Bcl-2 and TNF-R1 and decreased Fas. Methicillin-resistant S. aureus pneumonia thus induces organism-specific changes in intestinal apoptosis via changes in both the mitochondrial and receptor-mediated pathways, although the former may be more functionally significant.

In vitro biofilm formation by methicillin susceptible and resistant Staphylococcus aureus strains isolated from cystic fibrosis patients

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Antonietta Lambiase

2008-12-01

Full Text Available Staphylococcus aureus is one of the most common pathogens isolated from respiratory tracts of Cystic Fibrosis patients (CF. The infection by this pathogen starts in early infancy, often preceding chronic infections by Pseudomonas aeruginosa. The infection and colonization by methicillin-resistant Staphylococcus aureus (MRSA are, by then, events very frequent among CF patients and this bacterial isolation leads to complications in therapeutic management because of the limited treatment options. Strains of Staphylococcus aureus are able to produce biofilms on natural or synthetic surfaces. Biofilms are sophisticated communities of matrix-encased bacteria and infections by biofilm-producing bacteria are particularly problematic because sessile bacteria can often withstand host immune responses and are generally much more tolerant to antibiotics. The first aim of this work is to evaluate the ability of MRSA strains isolated from respiratory secretions of CF patients to develop biofilms in comparison with methicillin-sensitive Staphylococcus aureus (MSSA strains obtained from respiratory secretions of CF patients.Therefore, our second aim is to evaluate the environmental influence on this ability. To evaluate the development of biofilm on solid matrix and the possible environmental influence,we applied the method described by Christensen et al. We found that a significantly higher number of MRSA strains were biofilm positive compared with MSSA strains (p<0.05.The presence of glucose did not influence the ability to form biofilm in our MRSA strains (p=0.165. MSSA strains are not strong biofilm-producers, but, when grown in TSB added with 0.25% glucose, the number of biofilm-forming strains increases, as expected. These data suggest a possible association between methicillin-resistance and biofilm formation.

Zinc resistance of Staphylococcus aureus of animal origin is strongly associated with methicillin resistance

DEFF Research Database (Denmark)

Cavaco, Lina; Hasman, Henrik; Aarestrup, Frank Møller

2011-01-01

This study was conducted to determine the occurrence of zinc and copper resistances in methicillin-resistant Staphylococcus aureus (MRSA) from swine and veal calves in a global strain collection.The test population consisted of 476 porcine MRSA isolates from ten European countries, 18 porcine MRSA...... of the pig MRSA from Europe and the seven Chinese isolates belonged to other CCs and 3 isolates were not classified into a CC.All isolates were tested for susceptibility to zinc chloride and copper sulphate using agar dilution and tested by PCR for the czrC gene encoding zinc resistance.Phenotypic zinc...... resistance (MIC>2mM) was observed in 74% (n=324) and 42% (n=39) of European MRSA CC398 from pigs and veal calves, respectively, and in 44% of the Canadian isolates (n=8), but not among the Chinese isolates. Almost all (99%) zinc-resistant MRSA carried czrC. Of the 37 European non-CC398 MRSA, 62% were...

Investigational drugs to treat methicillin-resistant Staphylococcus aureus

Science.gov (United States)

Vuong, Cuong; Yeh, Anthony J; Cheung, Gordon YC; Otto, Michael

2016-01-01

Introduction Staphylococcus aureus remains one of the leading causes of morbidity and mortality worldwide. This is to a large extent due to antibiotic-resistant strains, in particular methicillin-resistant S. aureus (MRSA). While the toll of invasive MRSA infections appears to decrease in U.S. hospitals, the rate of community-associated MRSA infections remains constant and there is a surge of MRSA in many other countries. This situation calls for continuing if not increased efforts to find novel strategies to combat MRSA infections. Areas covered This review will provide an overview of current investigational antibiotics in clinical development (up to phase II), and of therapeutic antibodies and alternative drugs against S. aureus in preclinical and clinical development, including a short description of the mechanism of action and a presentation of microbiological and clinical data. Expert opinion Increased recent antibiotic development efforts and results from pathogenesis research have led to several new antibiotics and alternative drugs, as well as a more informed selection of targets for vaccination efforts against MRSA. This developing portfolio of novel anti-staphylococcal drugs will hopefully provide us with additional and more efficient ways to combat MRSA infections in the near future and prevent us from running out of treatment options, even if new resistances arise. PMID:26536498

Novel types of staphylococcal cassette chromosome mec elements identified in clonal complex 398 methicillin-resistant Staphylococcus aureus strains.

NARCIS (Netherlands)

Li, S.; Skov, R.L.; Han, X.; Larsen, A.R.; Larsen, J.; Sorum, M.; Wulf, M.; Voss, A.; Hiramatsu, K.; Ito, T.

2011-01-01

The structures of staphylococcal cassette chromosome mec (SCCmec) elements carried by 31 clonal complex 398 (CC398) methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from the participants at a conference were analyzed. The SCCmecs were classified into novel types, namely, IX, X,

Utilization of CHROMagar MRSA in the supervision of the methicillin-resistent Staphylococcus aureus

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Gabriella Corsi

2009-12-01

Full Text Available Methicillin-resistent Staphylococcus aureus (MRSA is one of the most common pathogen responsible for nosocomial infections. Laboratory diagnosis and assays of antimicrobial susceptibility are basic in controlling and preventing infection by MRSA. Our study was conducted for one year (May 2008-April 2009 on patients hospitalized to monitor the eventual colonization by MRSA.The use of chromogenic agar MRSA allowed us to identify pink-mauve colonies of MRSA within 24 hours and to make a timely e careful diagnosis.

Rapid Identification of Staphylococcus aureus and Methicillin Resistance by Flow Cytometry Using a Peptide Nucleic Acid Probe ▿

Science.gov (United States)

Shrestha, Nabin K.; Scalera, Nikole M.; Wilson, Deborah A.; Brehm-Stecher, Byron; Procop, Gary W.

2011-01-01

A total of 56 Staphylococcus aureus isolates incubated for 2 h in the presence or absence of oxacillin were analyzed by flow cytometry after labeling with an S. aureus-specific peptide nucleic acid (PNA) probe. Two defined ratios, the paired signal count ratio (PSCR) and the gate signal count ratio (GSCR), differentiated methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) with sensitivities of 100% each and specificities of 96% and 100%, respectively. PMID:21795508

Zinc Resistance within Swine-Associated Methicillin-Resistant Staphylococcus aureus Isolates in the United States Is Associated with Multilocus Sequence Type Lineage.

Science.gov (United States)

Hau, Samantha J; Frana, Timothy; Sun, Jisun; Davies, Peter R; Nicholson, Tracy L

2017-08-01

Zinc resistance in livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) sequence type 398 (ST398) is primarily mediated by the czrC gene colocated with the mecA gene, encoding methicillin resistance, within the type V staphylococcal cassette chromosome mec (SCC mec ) element. Because czrC and mecA are located within the same mobile genetic element, it has been suggested that the use of zinc in feed as an antidiarrheal agent has the potential to contribute to the emergence and spread of methicillin-resistant S. aureus (MRSA) in swine, through increased selection pressure to maintain the SCC mec element in isolates obtained from pigs. In this study, we report the prevalence of the czrC gene and phenotypic zinc resistance in U.S. swine-associated LA-MRSA ST5 isolates, MRSA ST5 isolates from humans with no swine contact, and U.S. swine-associated LA-MRSA ST398 isolates. We demonstrated that the prevalence of zinc resistance in U.S. swine-associated LA-MRSA ST5 isolates was significantly lower than the prevalence of zinc resistance in MRSA ST5 isolates from humans with no swine contact and swine-associated LA-MRSA ST398 isolates, as well as prevalences from previous reports describing zinc resistance in other LA-MRSA ST398 isolates. Collectively, our data suggest that selection pressure associated with zinc supplementation in feed is unlikely to have played a significant role in the emergence of LA-MRSA ST5 in the U.S. swine population. Additionally, our data indicate that zinc resistance is associated with the multilocus sequence type lineage, suggesting a potential link between the genetic lineage and the carriage of resistance determinants. IMPORTANCE Our data suggest that coselection thought to be associated with the use of zinc in feed as an antimicrobial agent is not playing a role in the emergence of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) ST5 in the U.S. swine population. Additionally, our data indicate

Role of ArlRS in autolysis in methicillin-sensitive and methicillin-resistant Staphylococcus aureus strains.

Science.gov (United States)

Memmi, Guido; Nair, Dhanalakshmi R; Cheung, Ambrose

2012-02-01

Autolysis plays an essential role in bacterial cell division and lysis with β-lactam antibiotics. Accordingly, the expression of autolysins is tightly regulated by several endogenous regulators, including ArlRS, a two component regulatory system that has been shown to negatively regulate autolysis in methicillin-sensitive Staphylococcus aureus (MSSA) strains. In this study, we found that inactivation of arlRS does not play a role in autolysis of methicillin-resistant S. aureus (MRSA) strains, such as community-acquired (CA)-MRSA strains USA300 and MW2 or the hospital-acquired (HA)-MRSA strain COL. This contrasts with MSSA strains, including Newman, SH1000, RN6390, and 8325-4, where autolysis is affected by ArlRS. We further demonstrated that the striking difference in the roles of arlRS between MSSA and MRSA strains is not due to the methicillin resistance determinant mecA. Among known autolysins and their regulators, we found that arlRS represses lytN, while no effect was seen on atl, lytM, and lytH expression in both CA- and HA-MRSA strains. Transcriptional-fusion assays showed that the agr transcripts, RNAII and RNAIII, were significantly more downregulated in the arlRS mutant of MW2 than the MSSA strain Newman. Importantly, provision of agr RNAIII in trans to the MW2 arlRS mutant via a multicopy plasmid induced autolysis in this MRSA strain. Also, the autolytic phenotype in the arlRS mutant of MSSA strain Newman could be rescued by a mutation in either atl or lytM. Together, these data showed that ArlRS impacts autolysis differently in MSSA and MRSA strains.

Inducible clindamycin and methicillin resistant Staphylococcus aureus in a tertiary care hospital, Kathmandu, Nepal.

Science.gov (United States)

Adhikari, R P; Shrestha, S; Barakoti, A; Amatya, R

2017-07-11

Staphylococcus aureus, an important nosocomial pathogen, is frequently associated with infections in human. The management of the infections by it especially methicillin resistant ones is often difficult because methicillin resistant S. aureus is usually resistant to multiple antibiotics. Macrolide-lincosamide streptogramin B family of antibiotics is commonly used to treat such infections as an alternative to vancomycin. This study was conducted over the period of one and half year from November 2013-April 2015 in Microbiology laboratory of Nepal Medical College and Teaching Hospital, Kathmandu, Nepal to find the incidence of different phenotypes of MLS B resistance among S. aureus from clinical samples and their association with methicillin resistance. Two hundred seventy isolates of S. aureus were included in the study. Methicillin resistance was detected by cefoxitin disc diffusion method and inducible clindamycin resistance by erythromycin and clindamycin disc approximation test (D-test). Of the 270 clinical isolates of S. aureus, 25.1% (68/270) were MRSA. Erythromycin and clindamycin resistance was seen in 54.4% (147/270) and 41.8% (113/270) isolates respectively. Resistance to erythromycin and clindamycin were higher in MRSA as compared to MSSA (erythromycin-resistance: 88.2% Vs 39.1% and clindamycin-resistance: 79.4% Vs 41.8%). The overall prevalence of i MLS B and c MLS B phenotype was 11.48% (31/270) and 29.25% (79/270) respectively. Both i MLS B and c MLS B phenotypes predominated in MRSA strains. Detection rate of MRSA in our study shows the necessity to improve in healthcare practices and to formulate new policy for the control of MRSA infections. Clindamycin resistance in the form of i MLS B and c MLS B especially among MRSA emphasizes the need of D-test to be performed routinely in our set up while using clindamycin as an alternative choice to anti-staphylococcal antibiotics like vancomycin and linezolid in the treatment of staphylococcal infections.

Prevalence of Methicillin?Resistant Staphylococcus aureus from Equine Nasopharyngeal and Guttural Pouch Wash Samples

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Boyle, A.G.; Rankin, S.C.; Duffee, L.A.; Morris, D.

2017-01-01

Background Methicillin?resistant Staphylococcus aureus (MRSA) is recognized as a cause of nosocomial infections in both human and veterinary medicine. Studies that examine the nasopharynx and guttural pouches of the horse as carriage sites for MRSA have not been reported. Hypothesis/Objective MRSA colonizes the nasopharynx and guttural pouch of horses. To determine the prevalence of MRSA in equine nasopharyngeal wash (NPW) and guttural pouch lavage (GPL) samples in a field population of horse...

'Prevalence and antimicrobial susceptibility of Listeria monocytogenes and methicillin-resistant Staphylococcus aureus strains from raw meat and meat products in Zaria, Nigeria.

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Ndahi, M D; Kwaga, J K P; Bello, M; Kabir, J; Umoh, V J; Yakubu, S E; Nok, A J

2014-03-01

The bacterial genera Listeria and Staphylococcus have been frequently isolated from food products and are responsible for a number of animal and human diseases. The aim of the study was to simultaneously isolate and characterize L. monocytogenes and Staphylococcus species from 300 samples of raw meat and meat products, to determine the susceptibility of the organisms to commonly used antimicrobial agents and to determine the presence of haemolysin A (hyl) virulence gene in L. monocytogenes and staphylococcal cassette chromosome mecA (SCCmec) gene in the Staph. aureus isolates using PCR. Of the 85 Listeria isolates tested, 12 L. monocytogenes were identified and tested for their sensitivity to 14 antimicrobial agents. All the 12 isolates (100%) were resistant to nine antimicrobial agents, but however sensitive to gentamicin. Only one isolate was found to harbour the hylA gene. Twenty-nine isolates were confirmed as Staph. aureus by the Microbact 12S identification system and were all presumptively identified as methicillin-resistant Staph. aureus species using oxacillin-resistant Staph. aureus basal medium (ORSAB). The 29 Staph. aureus isolates were tested for their sensitivity to 16 antimicrobial agents, and 11 were resistant to methicillin. None of the 11 Staph. aureus isolates harboured the methicillin resistance, mecA gene. Listeria monocytogenes and Staphylococcus aureus are important agents of foodborne diseases. Occurrence of these infectious agents was established in meat and meat products in Zaria, Nigeria. Majority of isolates obtained from this study, displayed multidrug resistance to commonly used antimicrobial agents, including methicillin resistance among the Staph. aureus isolates. The potential virulence of L. monocytogenes found in ready-to-eat food was documented by the carriage of hly A gene by one of the isolates. A different mechanism of methicillin resistance or different homologue of mec A gene may be circulating among Nigerian

Decolonization of patients and health care workers to control nosocomial spread of methicillin-resistant Staphylococcus aureus: a simulation study

NARCIS (Netherlands)

Gurieva, T.; Bootsma, M.C.; Bonten, M.J.M.

2012-01-01

Background Control of methicillin-resistant Staphylococcus aureus (MRSA) transmission has been unsuccessful in many hospitals. Recommended control measures include isolation of colonized patients, rather than decolonization of carriage among patients and/or health care workers. Yet, the potential

In vitro antibacterial activity of porous TiO2-Ag composite layers against methicillin-resistant Staphylococcus aureus

NARCIS (Netherlands)

Necula, Bogdan S.; Fratila-Apachitei, Lidy E.; Zaat, Sebastian A. J.; Apachitei, Iulian; Duszczyk, Jurek

2009-01-01

The aim of this study was the synthesis of a porous TiO(2)-Ag composite coating and assessment of its in vitro bactericidal activity against methicillin-resistant Staphylococcus aureus. The coating was produced by plasma electrolytic oxidation of Ti-6Al-7Nb medical alloy in a calcium acetate/calcium

Prevalence of Methicillin Resistant Staphylococcus aureus in Clinical Samples of Teerthankar Mahaveer Medical College Hospital and Research Centre (TMMCH & RC, Moradabad (UP, India

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Bina Pani Gupta

2017-06-01

Full Text Available Staphylococcus aureus is the emerging and prevalent pathogen causing serious infections in community and hospital associated diseases. S. aureus resistant to methicillin is nowadays a big and expanding problem of concern in India. Amongst the different pathogens, S. aureus is being studied for prevalence of infections and drug resistance behavior. The present study describes the dominance of Staphylococcus aureus prevalence in the clinical samples of TMU, Moradabad, India. The study showed the isolation of 450 cultures of S. aureus from different samples. Amongst which, 234 isolates of S. aureus were from pus, 164 isolates were from blood, 15 isolates were from respiratory fluid samples, 33 isolates were from urine samples and 04 isolates were from ear swabs and nasal swabs. These strains of S. aureus were screened for characteristic coagulase assay. The strains were found to be coagulase positive and coagulases negative both. It was observed that, amongst, 450 isolates of Staphylococci, 185 (41.11% strains were coagulase positive and 265 (58.88% were coagulase negative. A total of 142 (76.75% of the coagulase positive staphylococci strains shows resistance to methicillin and 202 (76.22% coagulase negative strains showed methicillin resistance. Methicillin resistance was consistent when tested with other antibiotics in coagulase positive strains but when studied about coagulase negative strains, about 12.5% strains showed sensitivity with other antibiotics although they were found resistant when checked with methicillin. It was determined that, on an average, 85 (18.88% Staphylococci strains were resistant.

Molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from patients with bacteremia based on MLST, SCCmec, spa, and agr locus types analysis.

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Goudarzi, Mehdi; Seyedjavadi, Sima Sadat; Nasiri, Mohammad Javad; Goudarzi, Hossein; Sajadi Nia, Raheleh; Dabiri, Hossein

2017-03-01

The widespread emergence of methicillin resistant Staphylococcus aureus, as a common cause of nosocomial infections, is becoming a serious concern in global public health. The objective of the present study was to investigate antimicrobial susceptibility pattern, frequency of virulence genes and molecular characteristics of methicillin-resistant Staphylococcus aureus strains isolated from patients with bacteremia. A total of 128 methicillin-resistant Staphylococcus aureus isolates were collected during February 2015 to January 2016. In vitro antimicrobial susceptibility of the isolates was assessed using the disk diffusion method. Conventional PCR was performed for the detection of adhesion (can, bbp, ebp, fnbB, fnbA, clfB, clfA) and toxin (etb, eta, pvl, tst) encoding genes, determining the agr type, SCCmec, MLST and spa typing of the isolates. All the methicillin-resistant Staphylococcus aureus isolates were found to be sensitive to linezolid, teicoplanin, and vancomycin. Resistance to the tested antibiotics varied from 97.7% for penicillin to 24.2% for mupirocin. The rate of multi drug resistance (MDR) in the present study was 97.7%. The most commonly detected toxin and adhesion genes were tst (58.6%), and clfB (100%), respectively. The majority of SCCmec III isolates were found in agr group I while SCCmec IV and II isolates were distributed among agr group III. Multilocus Sequence Typing (MLST) of the MRSA isolates showed five different sequence types: ST239 (43%), ST22 (39.8%), ST585 (10.9%), ST45 (3.9%) and ST240 (2.3%). All of the pvl positive strains belonged to ST22-SCCmec IV/t790 clone and were MDR. Among different 7 spa types, the most common were t790 (27.3%), t037 (21.9%), and t030 (14.1%). spa types t016, t924 and spa type t383 were reported for the first time from Asia and Iran, respectively. It was shown that spa types circulating in the studied hospitals varied which support the need to perform future surveillance studies in order to understand

Has the emergence of community-associated methicillin-resistant Staphylococcus aureus increased trimethoprim-sulfamethoxazole use and resistance?: a 10-year time series analysis.

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Wood, Jameson B; Smith, Donald B; Baker, Errol H; Brecher, Stephen M; Gupta, Kalpana

2012-11-01

There are an increasing number of indications for trimethoprim-sulfamethoxazole use, including skin and soft tissue infections due to community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA). Assessing the relationship between rates of use and antibiotic resistance is important for maintaining the expected efficacy of this drug for guideline-recommended conditions. Using interrupted time series analysis, we aimed to determine whether the 2005 emergence of CA-MRSA and recommendations of trimethoprim-sulfamethoxazole as the preferred therapy were associated with changes in trimethoprim-sulfamethoxazole use and susceptibility rates. The data from all VA Boston Health Care System facilities, including 118,863 inpatient admissions, 6,272,661 outpatient clinic visits, and 10,138 isolates were collected over a 10-year period. There was a significant (P = 0.02) increase in trimethoprim-sulfamethoxazole prescriptions in the post-CA-MRSA period (1,605/year) compared to the pre-CA-MRSA period (1,538/year). Although the overall susceptibility of Escherichia coli and Proteus spp. to trimethoprim-sulfamethoxazole decreased over the study period, the rate of change in the pre- versus the post-CA-MRSA period was not significantly different. The changes in susceptibility rates of S. aureus to trimethoprim-sulfamethoxazole and to methicillin were also not significantly different. The CA-MRSA period is associated with a significant increase in use of trimethoprim-sulfamethoxazole but not with significant changes in the rates of susceptibilities among clinical isolates. There is also no evidence for selection of organisms with increased resistance to other antimicrobials in relation to increased trimethoprim-sulfamethoxazole use.

[Molecular characterization of resistance mechanisms: methicillin resistance Staphylococcus aureus, extended spectrum β-lactamases and carbapenemases].

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Oteo, Jesús; Belén Aracil, María

2015-07-01

Multi-drug resistance in bacterial pathogens increases morbidity and mortality in infected patients and it is a threat to public health concern by their high capacity to spread. For both reasons, the rapid detection of multi-drug resistant bacteria is critical. Standard microbiological procedures require 48-72 h to provide the antimicrobial susceptibility results, thus there is emerging interest in the development of rapid detection techniques. In recent years, the use of selective and differential culture-based methods has widely spread. However, the capacity for detecting antibiotic resistance genes and their low turnaround times has made molecular methods a reference for diagnosis of multidrug resistance. This review focusses on the molecular methods for detecting some mechanisms of antibiotic resistance with a high clinical and epidemiological impact: a) Enzymatic resistance to broad spectrum β-lactam antibiotics in Enterobacteriaceae, mainly extended spectrum β-lactamases (ESBL) and carbapenemases; and b) methicillin resistance in Staphylococcus aureus. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.

Bactericidal antibiotic-phytochemical combinations against methicillin resistant Staphylococcus aureus

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Bhone Myint Kyaw

2012-09-01

Full Text Available Methicillin resistant Staphylococcus aureus (MRSA infection is a global concern nowadays. Due to its multi-drug resistant nature, treatment with conventional antibiotics does not assure desired clinical outcomes. Therefore, there is a need to find new compounds and/or alternative methods to get arsenal against the pathogen. Combination therapies using conventional antibiotics and phytochemicals fulfill both requirements. In this study, the efficacy of different phytochemicals in combination with selected antibiotics was tested against 12 strains of S. aureus (ATCC MRSA 43300, ATCC methicillin sensitive S. aureus or MSSA 29213 and 10 MRSA clinical strains collected from National University Hospital, Singapore. Out of the six phytochemicals used, tannic acid was synergistic with fusidic acid, minocycline, cefotaxime and rifampicin against most of strains tested and additive with ofloxacin and vancomycin. Quercetin showed synergism with minocycline, fusidic acid and rifampicin against most of the strains. Gallic acid ethyl ester showed additivity against all strains in combination with all antibiotics under investigation except with vancomycin where it showed indifference effect. Eugenol, menthone and caffeic acid showed indifference results against all strains in combination with all antibiotics. Interestingly, no antagonism was observed within these interactions. Based on the fractional inhibitory concentration indices, synergistic pairs were further examined by time-kill assays to confirm the accuracy and killing rate of the combinations over time. The two methods concurred with each other with 92% accuracy and the combinatory pairs were effective throughout the 24 hours of assay. The study suggests a possible incorporation of effective phytochemicals in combination therapies for MRSA infections.

Genome-Wide High-Throughput Screening to Investigate Essential Genes Involved in Methicillin-Resistant Staphylococcus aureus Sequence Type 398 Survival

DEFF Research Database (Denmark)

Christiansen, Mette Theilgaard; Kaas, Rolf Sommer; Chaudhuri, Roy R.

2014-01-01

Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) Sequence Type 398 (ST398) is an opportunistic pathogen that is able to colonize and cause disease in several animal species including humans. To better understand the adaptation, evolution, transmission and pathogenic...

Surveillance of colonization and infection with Staphylococcus aureus susceptible or resistant to methicillin in a community skilled-nursing facility

NARCIS (Netherlands)

Y.-L. Lee (Yee-Lean); T. Cesario (Thomas); G.K. Gupta (Geeta); L. Flionis (Leo); C.T. Tran (Chi); M. Decker (Michael); L.D. Thrupp (Lauri)

1997-01-01

textabstractBackground: Methicillin-resistant Staphylococcus aureus (MRSA) is an important nosocomial pathogen in acute care hospitals and long-term care facilities. Few studies have been reported in private skilled nursing facilities (SNFs) not experiencing outbreaks of infections caused by MRSA.

Prevalence of Methicillin-Resistant Staphylococcus aureus from Equine Nasopharyngeal and Guttural Pouch Wash Samples.

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Boyle, A G; Rankin, S C; Duffee, L A; Morris, D

2017-09-01

Methicillin-resistant Staphylococcus aureus (MRSA) is recognized as a cause of nosocomial infections in both human and veterinary medicine. Studies that examine the nasopharynx and guttural pouches of the horse as carriage sites for MRSA have not been reported. MRSA colonizes the nasopharynx and guttural pouch of horses. To determine the prevalence of MRSA in equine nasopharyngeal wash (NPW) and guttural pouch lavage (GPL) samples in a field population of horses. One hundred seventy-eight samples (123 NPW and 55 GPL) from 108 horses. Prospective study. Samples were collected from a convenience population of clinically ill horses with suspected Streptococcus equi subsp. equi (S. equi) infection, horses convalescing from a known S. equi infection, and asymptomatic horses undergoing S. equi screening. Samples were submitted for S. aureus aerobic bacterial culture with mannitol salt broth and two selective agars (cefoxitin CHROMagar as the PBP2a inducer and mannitol salt agar with oxacillin). Biochemical identification of Staphylococcus species and pulsed-field gel electrophoresis (PFGE), to determine clonal relationships between isolates, were performed. Methicillin-resistant Staphylococcus (MRS) was isolated from the nasopharynx of 7/108 (4%) horses. Three horses had MRSA (2.7%), and 4 had MR-Staphylococcus pseudintermedius (MRSP). MRSA was isolated from horses on the same farm. PFGE revealed the 3 MRSA as USA 500 strains. Sampling the nasopharynx and guttural pouch of community-based horses revealed a similarly low prevalence rate of MRSA as other studies sampling the nares of community-based horses. More study is required to determine the need for sampling multiple anatomic sites when screening horses for MRSA. Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Genetic diversity of methicillin-resistant Staphylococcus aureus in a tertiary hospital in The Netherlands between 2002 and 2006

NARCIS (Netherlands)

Nulens, E; Stobberingh, E E; Smeets, E; van Dessel, H; Welling, M A; Sebastian, S; van Tiel, F H; Beisser, P S; Deurenberg, R H

The aim of this study was to investigate the methicillin-resistant Staphylococcus aureus (MRSA) clones isolated in a Dutch university hospital, situated near the borders of Belgium and Germany, between 2002 and 2006. MRSA strains (n = 175) were characterized using spa and SCCmec typing. The presence

Antibiotic resistance patterns of coagulase-negative staphylococcus strains isolated from blood cultures of septicemic patients in Turkey.

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Koksal, F; Yasar, H; Samasti, M

2009-01-01

The aim of this study is to determine antibiotic resistance patterns and slime production characteristics of coagulase-negative Staphylococci (CoNS) caused nosocomial bacteremia. A total of 200 CoNS strains were isolated from blood samples of patients with true bacteremia who were hospitalized in intensive care units and in other departments of Istanbul University Cerrahpasa Medical Hospital between 1999 and 2006. Among 200 CoNS isolates, Staphylococcus epidermidis was the most prevalent species (87) followed by Staphylococcus haemolyticus (23), Staphylococcus hominis (19), Staphylococcus lugdunensis (18), Staphylococcus capitis (15), Staphylococcus xylosus (10), Staphylococcus warneri (8), Staphylococcus saprophyticus (5), Staphylococcus lentus (5), Staphylococcus simulans (4), Staphylococcus chromogenes (3), Staphylococcus cohnii (1), Staphylococcus schleiferi (1), and Staphylococcus auricularis (1). Resistance to methicillin was detected in 67.5% of CoNS isolates. Methicillin-resistant CoNS strains were determined to be more resistant to antibiotics than methicillin-susceptible CoNS strains. Resistance rates of methicillin-resistant and methicillin-susceptible CoNS strains to the antibacterial agents, respectively, were as follows: gentamicin 90% and 17%, erythromycin 80% and 37%, clindamycin 72% and 18%, trimethoprim-sulfamethoxazole 68% and 38%, ciprofloxacin 67% and 23%, tetracycline 60% and 45%, chloramphenicol 56% and 13% and fusidic acid 25% and 15%. None of the strains were resistant to vancomycin and teicoplanin. Slime production was detected in 86 of 200 CoNS strains. Resistance to methicillin was found in 81% of slime-positive and in 57% of slime-negative strains. Our results indicated that there is a high level of resistance to widely used agents in causative methicillin-resistant CoNS strains. However fusidic acid has the smallest resistance ratio, with the exception of glycopeptides. Additionally, most S. epidermidis strains were slime

Sub-acute mastitis associated with Methicillin Resistant Staphylococcus aureus in a cow: A case report

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Duraisamy Chandrasekaran

2014-12-01

Full Text Available A 5-year old Holstein Friesian cross breed cow was presented to Madras Veterinary College Teaching Hospital with the history of reduced milk yield. Clinical examination of udder revealed normal milk color and soft udder. The milk pH was 7.0, with California Mastitis Test score 3+, Electrical Conductivity 270U, and Somatic Cell Count as 328,000. Isolation and identification of causative agent revealed Methicillin Resistant Staphylococcus aureus (MRSA from the sub-acute mastitis sample. Agar disc diffusion method for antimicrobial susceptibility revealed that the MRSA was sensitive to Enrofloxacin, Gentamicin, Oxytetracycline and Amoxicillin+Sulbactam. On the other hand, the isolate was resistance to Amoxicillin, Penicillin G, Ceftriaxone and Methicillin. The isolate was positive for β-lactamase resistance by Nitrocefin test. The MRSA was confirmed for the presence of mecA and blaZ target genes by polymerase chain reaction (PCR. The cow was treated with Enrofloxacin, Vitamin E and inorganic Selenium, and was recovered after 5 days of post-treatment.

Prevention and Control of Methicillin-Resistant Staphylococcus aureus in Acute Care Settings.

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Lee, Andie S; Huttner, Benedikt; Harbarth, Stephan

2016-12-01

Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of health care-associated infections worldwide. Controversies with regard to the effectiveness of various MRSA control strategies have contributed to varying approaches to the control of this pathogen in different settings. However, new evidence from large-scale studies has emerged, particularly with regards to MRSA screening and decolonization strategies, which will inform future control practices. The implementation as well as outcomes of control measures in the real world is not only influenced by scientific evidence but also depends on economic, administrative, governmental, and political influences. Copyright © 2016 Elsevier Inc. All rights reserved.

Activity of linezolid and tedizolid against clinical isolates of methicillin-resistant and methicillin and linezolid resistant Staphylococcus aureus: an in vitro comparison.

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Peñuelas, M; Candel, F J; Lejarraga, C; López-González, L; Viñuela-Prieto, J M; López de Mendoza, D

2016-10-01

The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in Spain is approximately 20-30%. However, resistance to linezolid is rare, and the main reports are from nosocomial outbreaks. The objective of the present study was to compare the in vitro susceptibility of linezolid with that of tedizolid against MRSA isolates and methicillin-and linezolid-resistant isolates (MLRSA) mediated by the cfr gene. The in vitro susceptibility of linezolid and tedizolid was determined using the E-test with 18 MRSA strains and 18 cfr-mediated MLRSA strains obtained from clinical isolates in the microbiology service of a tertiary university hospital. All MRSA strains were susceptible to both antibiotics. Analysis of the MRSA isolates revealed that the MIC50 and MIC90 of linezolid were 1.5 and 2 mg/L, respectively; those of tedizolid were 0.25 and 0.4 mg/L. The MIC50 and MIC90 of tedizolid remained at 0.75 and 1 mg/L against the MLRSA strains (MIC90 ≥ 8 mg/L). Both for MRSA and for MLRSA, the MICs obtained for tedizolid were at least 2 dilutions lower than those of linezolid, thus demonstrating between 2 and 4 times greater activity in vitro than linezolid.

Community-acquired methicillin-resistant Staphylococcus aureus: an emerging pathogen in orthopaedics.

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Marcotte, Anthony L; Trzeciak, Marc A

2008-02-01

Staphylococcus aureus (S aureus) remains one of the most common pathogens for skin and soft-tissue infections encountered by the orthopaedic surgeon. Community-acquired methicillin-resistant S aureus (CA-MRSA) has become increasingly prevalent, particularly among athletes, children in day care, homeless persons, intravenous drug users, men who have sex with men, military recruits, certain minorities (ie, Alaskan Natives, Native Americans, Pacific Islanders), and prison inmates. Risk factors include antibiotic use within the preceding year, crowded living conditions, compromised skin integrity, contaminated surfaces, frequent skin-to-skin contact, shared items, and suboptimal cleanliness. When a patient presents with a skin or soft-tissue infection, the clinician should determine whether an abscess or other infection needs to be surgically incised and drained. Cultures should be performed. When the patient is a member of an at-risk group or has any of the risk factors for CA-MRSA, beta-lactam antibiotics (eg, methicillin) are no longer a reasonable choice for treatment. Empiric treatment should consist of non-beta-lactam antibiotics active against CA-MRSA.

Methicillin-resistant Staphylococcus aureus in North-east Croatia

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Tajana Pastuović

2015-05-01

Full Text Available Objective. The aim of this 5-year study was to determine the frequency and antibiotic susceptibility of methicillin-resistant Staphylococcus aureus (MRSA-related infections at Osijek Clinical Hospital. Materials and methods. A total of 1987 staphylococci-infected clinical isolates were collected and analysed at the Microbiology Department of the Public Health Institute of Osijek-Baranja County. Results. Between 2008 and 2012, the average rate of MRSA-related infections in staphylococci-infected patients was 27.4%. The proportion of MRSArelated infections on all Staphylococcus aureus (S. aureus isolates from clinical specimens showed a decreasing trend, from 32.6% in 2008 to 25.5% in 2012. MRSA-related infections were mostly detected in wound swabs (50.6% and aspirates (28.8% of patients hospitalized in the surgical (49.8% and intensive care units (27.9%. MRSA-related infection showed an increase compared to S. aureus-infections in samples of wounds and aspirates in 2011 and 2012 (57.9%/34.9% and 35.2%/16.3%, respectively. The majority of strains of MRSA-related infections were resistant to several antibiotics, including erythromycin and clindamycin, where susceptibility were less than 10%. All MRSA isolates were susceptible to vancomycin, teicoplanin and linezolid. Therefore, antibiotic therapies for MRSA infections include vancomycin, teicoplanin and linezolid, but microbiological diagnostics need to be performed in order to know when the use of glycopeptides and oxazolidinones is indicated. Conclusion. Our results suggest that appropriate prevention measures, combined with the more rational use of antibiotics are crucial to reduce the spread of MRSA-related infection in healthcare settings. Further monitoring is necessary of the incidence and antibiotic susceptibility of MRSA-related infections in our community.

Genetic Determinants of High-Level Oxacillin Resistance in Methicillin-Resistant Staphylococcus aureus.

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Pardos de la Gandara, Maria; Borges, Vitor; Chung, Marilyn; Milheiriço, Catarina; Gomes, João Paulo; de Lencastre, Herminia; Tomasz, Alexander

2018-06-01

Methicillin-resistant Staphylococcus aureus (MRSA) strains carry either a mecA - or a mecC -mediated mechanism of resistance to beta-lactam antibiotics, and the phenotypic expression of resistance shows extensive strain-to-strain variation. In recent communications, we identified the genetic determinants associated with the stringent stress response that play a major role in the antibiotic resistant phenotype of the historically earliest "archaic" clone of MRSA and in the mecC -carrying MRSA strain LGA251. Here, we sought to test whether or not the same genetic determinants also contribute to the resistant phenotype of highly and homogeneously resistant (H*R) derivatives of a major contemporary MRSA clone, USA300. We found that the resistance phenotype was linked to six genes ( fruB , gmk , hpt , purB , prsA , and relA ), which were most frequently targeted among the analyzed 20 H*R strains (one mutation per clone in 19 of the 20 H*R strains). Besides the strong parallels with our previous findings (five of the six genes matched), all but one of the repeatedly targeted genes were found to be linked to guanine metabolism, pointing to the key role that this pathway plays in defining the level of antibiotic resistance independent of the clonal type of MRSA. Copyright © 2018 American Society for Microbiology.

Influence of red laser irradiation and photosensitizers Photoditazine and Dimegin on the growth of methicillin-resistant strain of Staphylococcus aureus

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Brill, G. E.; Egorova, A. V.; Bugaeva, I. O.; Tuchina, E. S.; Morozov, O. A.; Ponomaryov, G. V.; Ushakova, O. V.

2017-03-01

The influence of red laser irradiation on the growth of colonies of methicillin-resistant strain of Staphylococcus aureus and photodynamic effects of the photosensitizers Photoditazine and Dimegin were performed. It was established that the red semiconductor laser (λ - 660 nm, 100 mW/cm2) at 10-, 15- and 30-mins exposure, has a direct bacteriostatic action on the growth of S. aureus. Pre-treatment of bacterial cells by Photoditazine significantly enhances the inhibitory effect. The photosensitizing action of Dimegin does not appear at influence on methicillin-resistant S. aureus.

Production of low-affinity penicillin-binding protein by low- and high-resistance groups of methicillin-resistant Staphylococcus aureus.

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Murakami, K; Nomura, K; Doi, M; Yoshida, T

1987-01-01

Methicillin- and cephem-resistant Staphylococcus aureus (137 strains) for which the cefazolin MICs are at least 25 micrograms/ml could be classified into low-resistance (83% of strains) and high-resistance (the remaining 17%) groups by the MIC of flomoxef (6315-S), a 1-oxacephalosporin. The MICs were less than 6.3 micrograms/ml and more than 12.5 micrograms/ml in the low- and high-resistance groups, respectively. All strains produced penicillin-binding protein 2' (PBP 2'), which has been associated with methicillin resistance and which has very low affinity for beta-lactam antibiotics. Production of PBP 2' was regulated differently in low- and high-resistance strains. With penicillinase-producing strains of the low-resistance group, cefazolin, cefamandole, and cefmetazole induced PBP 2' production about 5-fold, while flomoxef induced production 2.4-fold or less. In contrast, penicillinase-negative variants of low-resistance strains produced PBP 2' constitutively in large amounts and induction did not occur. With high-resistance strains, flomoxef induced PBP 2' to an extent similar to that of cefazolin in both penicillinase-producing and -negative strains, except for one strain in which the induction did not occur. The amount of PBP 2' induced by beta-lactam antibiotics in penicillinase-producing strains of the low-resistance group correlated well with resistance to each antibiotic. Large amounts of PBP 2' in penicillinase-negative variants of the low-resistance group did not raise the MICs of beta-lactam compounds, although these strains were more resistant when challenged with flomoxef for 2 h. Different regulation of PBP 2' production was demonstrated in the high- and low-resistance groups, and factor(s) other than PBP 2' were suggested to be involved in the methicillin resistance of high-resistance strains. Images PMID:3499861

Nasal carriage of methicilli-resistant staphylococcus aureus with ...

African Journals Online (AJOL)

Staphylococcus aureus isolates were collected from anterior nares of fifty healthy adults in Zaria and their antibiotic susceptibility patterns determined. Seventy-two percent (72%) of the isolates were methicillin-resistant S. aureus, while 20% were methicillin-susceptible. The isolates were generally resistant to multiple ...

Prevalence of methicillin resistance and macrolide-lincosamide-streptogramin B resistance in Staphylococcus haemolyticus among clinical strains at a tertiary-care hospital in Thailand.

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Teeraputon, S; Santanirand, P; Wongchai, T; Songjang, W; Lapsomthob, N; Jaikrasun, D; Toonkaew, S; Tophon, P

2017-09-01

Staphylococcus spp. is a major cause of nosocomial infection and sepsis. However, increasing drug resistance is becoming a challenge to microbiologists. The purpose of this study was to identify and determine antimicrobial resistance phenotypes and drug resistance genes of clinical coagulase-negative staphylococci (CoNS) isolates at Mae Sot Hospital in Tak province, Thailand. A total of 229 CoNS isolates were collected from clinical specimens during two periods in 2014 and in 2015. Staphylococcus haemolyticus was the most prevalent species (37.55%), followed by S. epidermidis (21.83%), S. saprophyticus (11.79%) and S. hominis (11.35%) respectively. The remaining 17.48% of the organisms comprised S. capitis, S. arlettae, S. cohnii, S. equorum, S. xylosus, S. warneri, S. sciuri, S. pettenkoferi, S. kloosii and S. lugdunensis. Methicillin-resistant CoNS (MRCoNS), containing the mec A gene, were detected in 145 of 229 isolates, mostly found in S. haemolyticus and S. epidermidis. In addition, the differentiation of their macrolide-lincosamide-streptogramin B (MLS B ) resistance phenotypes was determined by the D-test and corresponding resistance genes. Among 125 erythromycin-resistant CoNS, the prevalence of constitutive type of MLS B , inducible clindamycin resistance and macrolide-streptogramin B resistance phenotypes were 72, 13.60 and 14.40% respectively. These phenotypes were expressed in 80% of MRCoNS strains. In addition, the erm C gene (79.20%) was found to be more prevalent than the erm A gene (22.40%), especially among MRCoNS. These results indicate that CoNS may play an important role in spreading of drug resistance genes. More attention to these organisms in surveillance and monitoring programs is needed.

Prevalence of methicillin resistance and macrolide–lincosamide–streptogramin B resistance in Staphylococcus haemolyticus among clinical strains at a tertiary-care hospital in Thailand

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S. Teeraputon

2017-09-01

Full Text Available Staphylococcus spp. is a major cause of nosocomial infection and sepsis. However, increasing drug resistance is becoming a challenge to microbiologists. The purpose of this study was to identify and determine antimicrobial resistance phenotypes and drug resistance genes of clinical coagulase-negative staphylococci (CoNS isolates at Mae Sot Hospital in Tak province, Thailand. A total of 229 CoNS isolates were collected from clinical specimens during two periods in 2014 and in 2015. Staphylococcus haemolyticus was the most prevalent species (37.55%, followed by S. epidermidis (21.83%, S. saprophyticus (11.79% and S. hominis (11.35% respectively. The remaining 17.48% of the organisms comprised S. capitis, S. arlettae, S. cohnii, S. equorum, S. xylosus, S. warneri, S. sciuri, S. pettenkoferi, S. kloosii and S. lugdunensis. Methicillin-resistant CoNS (MRCoNS, containing the mecA gene, were detected in 145 of 229 isolates, mostly found in S. haemolyticus and S. epidermidis. In addition, the differentiation of their macrolide–lincosamide–streptogramin B (MLSB resistance phenotypes was determined by the D-test and corresponding resistance genes. Among 125 erythromycin-resistant CoNS, the prevalence of constitutive type of MLSB, inducible clindamycin resistance and macrolide–streptogramin B resistance phenotypes were 72, 13.60 and 14.40% respectively. These phenotypes were expressed in 80% of MRCoNS strains. In addition, the ermC gene (79.20% was found to be more prevalent than the ermA gene (22.40%, especially among MRCoNS. These results indicate that CoNS may play an important role in spreading of drug resistance genes. More attention to these organisms in surveillance and monitoring programs is needed.

Review of a major epidemic of methicillin-resistant Staphylococcus aureus: The costs of screening and consequences of outbreak management

NARCIS (Netherlands)

A. van der Zee (Anneke); W. Hendriks; L.D. Roorda (Lieuwe); J.M. Ossewaarde (Jacobus); J. Buitenwerf (Johannes)

2013-01-01

textabstractBackground: A major outbreak of methicillin-resistant Staphylococcus aureus (MRSA) occurred in locations C and Z of our hospital and lasted for several years. It affected 1,230 patients and 153 personnel. Methods: Outbreak management was installed according to the Dutch "search and

Methicillin-resistant Staphylococcus aureus in horses and horse personnel: An investigation of several outbreaks

OpenAIRE

Duijkeren, E. van; Moleman, M.; Sloet van Oldruitenborgh-Oosterbaan, M.M.; Multem, J.D.; Troelstra, A.; Fluit, A.C.; Wamel, W.J.B. van; Houwers, D.J.; Neeling, A.J. de; Wagenaar, J.A.

2009-01-01

At the Veterinary Microbiological Diagnostic Center, the Netherlands, the percentage of methicillin-resistant Staphylococcus aureus (MRSA) isolates found in equine clinical samples increased from 0% in 2002 to 37% in 2008. MRSA of spa-type t064, belonging to MLST ST8 and spa-types t011 and t2123, both belonging to the livestock-associated MLST ST398, predominated. During an outbreak of post-surgical MRSA infections in horses at a veterinary teaching hospital in2006/2007,MRSAisolates of spa-ty...

Potential Mechanism of Action of 3'-Demethoxy-6-O-demethyl-isoguaiacin on Methicillin Resistant Staphylococcus aureus.

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Favela-Hernández, Juan Manuel J; Clemente-Soto, Aldo F; Balderas-Rentería, Isaías; Garza-González, Elvira; Camacho-Corona, María del Rayo

2015-07-08

Bacterial infections represent one of the main threats to global public health. One of the major causative agents associated with high morbidity and mortality infections in hospitals worldwide is methicillin-resistant Staphylococcus aureus. Therefore, there is a need to develop new antibacterial agents to treat these infections, and natural products are a rich source of them. In previous studies, we reported that lignan 3'-demethoxy-6-O-demethylisoguaiacin, isolated and characterized from Larrea tridentate, showed the best activity towards methicillin-resistant S. aureus. Thus, the aim of this study was to determine the potential molecular mechanism of the antibacterial activity of 3'-demethoxy-6-O-demethylisoguaiacin against methicillin-resistant S. aureus using microarray technology. Results of microarray genome expression were validated by real-time polymerase chain reaction (RT-PCR). The genetic profile expression results showed that lignan 3'-demethoxy-6-O-demethylisoguaiacin had activity on cell membrane affecting proteins of the ATP-binding cassette (ABC) transport system causing bacteria death. This molecular mechanism is not present in any antibacterial commercial drug and could be a new target for the development of novel antibacterial agents.

Epidemiology of drug resistance: The case of Staphylococcus aureus and coagulase-negative staphylococci infections Epidemiología de la resistencia bacteriana: el caso de Staphylococcus aureus y las infecciones Staphylococcus coagulasa negativas

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Ernesto Calderón-Jaimes

2002-04-01

Full Text Available Objective. To study the activity of several antibiotics against Staphylococcus spp. Material and Methods. The study included 1209 strains of Staphylococcus spp. from two institutions; Instituto Nacional de Pediatría (National Institute of Pediatrics and Hospital Infantil de México Federico Gómez (Mexico City Children's Hospital. Minimum Inhibitory Concentrations of all antibiotics were determined by the agar macrodilution technique and standard methods from the National Committee for Clinical Laboratory Standards. Results. Resistance of S. aureus was 14.2% and that of coagulase-negative staphylococci was 53.4%. The activity of different antibiotics is presented in detail. Conclusions. Surveillance of strains resistant to methicillin is necessary.Objetivo. Determinar la frecuencia de la resistencia a la meticilina y la actividad de varios antibióticos. Material y métodos. Se incluyeron 1 209 cepas de Staphylococcus spp. procedentes de pacientes del Instituto Nacional de Pediatría y del Hospital Infantil de México Federico Gómez. Se utilizó la técnica de dilución en placas con agar. El procedimiento e interpretación fueron acordes con lo establecido por el National Committee for Clinical Laboratory Standards. Resultados. La frecuencia de la resistencia de S. aureus fue de 14.2% y de 53.4% en los Staphylococcus coagulasa negativa. La actividad de otros antimicrobianos se presenta en el texto. Conclusiones. Es necesario vigilar continuamente la progresión de la resistencia de Staphylococcus spp. a la meticilina.

Sepse por Staphylococus aureus resistente à meticilina adquirida na comunidade no sul do Brasil Sepsis due to community-acquired methicillin-resistant Staphylococcus aureus in southern Brazil

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Luciane Cristina Gelatti

2009-08-01

Full Text Available Staphylococcus aureus resistente à meticilina foi inicialmente descrito como um típico microrganismo adquirido em infecções nosocomiais. No entanto, nos últimos anos Staphylococcus aureus resistente à meticilina adquirido na comunidade é causa de infecções de pele e tecidos moles, mas infecções graves como pneumonia e sepse podem ocorrer. Este relato descreve um caso de sepse em criança, complicado com pneumonia secundária a lesão em partes moles por Staphylococcus aureus resistente à meticilina adquirido na comunidade no Sul do Brasil. O paciente foi atendido em Unidade de Emergência com história de ferimento provocado por trauma em membro inferior que evoluiu para celulite, pneumonia e sepse.Methicillin-resistant Staphylococcus aureus was initially described as a typical microorganism acquired in nosocomial infections. However, over recent years, community-acquired methicillin-resistant Staphylococcus aureus has been a cause of skin and soft-tissue infections. Serious infections such as pneumonia and sepsis can also occur. This report describes a case of sepsis in a child that was complicated by pneumonia secondary to soft tissue lesions that were due to community-acquired methicillin-resistant Staphylococcus aureus in southern Brazil. The patient was attended at the Emergency Unit with a history of injury caused by lower-limb trauma that evolved to cellulitis, pneumonia and sepsis.

A Nosocomial Outbreak of Community-Associated Methicillin-Resistant Staphylococcus aureus among Healthy Newborns and Postpartum Mothers

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Andrea Saunders

2007-01-01

Full Text Available BACKGROUND: Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA has increasingly been isolated from individuals with no predisposing risk factors; however, such strains have rarely been linked to outbreaks in the hospital setting. The present study describes the investigation of an outbreak of CA-MRSA that occurred in the maternal-newborn unit of a large community teaching hospital in Toronto, Ontario.

Antimicrobial susceptibility of methicillin-resistant Staphylococcus pseudintermedius isolated from veterinary clinical cases in the UK.

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Maluping, R P; Paul, N C; Moodley, A

2014-01-01

Staphylococcus pseudintermedius is a leading aetiologic agent of pyoderma and other body tissue infections in dogs and cats. In recent years, an increased prevalence of methicillin-resistant S. pseudintermedius (MRSP) has been reported. Isolation of MRSP in serious infections poses a major therapeutic challenge as strains are often resistant to all forms of systemic antibiotic used to treat S. pseudintermedius -related infections. This study investigates the occurrence of MRSP from a total of 7183 clinical samples submitted to the authors' laboratories over a 15-month period. Identification was based on standard microbiological identification methods, and by S. pseudintermedius-specific nuc polymerase chain reaction (PCR). Methicillin resistance was confirmed by PBP2a latex agglutination and mecA PCR. Susceptibility against non-beta-lactam antibiotics was carried out using a disc-diffusion method according to Clinical and Laboratory Standards Institute (CLSI) guidelines. In addition, susceptibility to pradofloxacin--a new veterinary fluoroquinolone--was also investigated. SCCmec types were determined by multiplex PCR. Staphylococcus pseudintermedius was isolated from 391 (5%) samples and 20 were confirmed as MRSP from cases of pyoderma, otitis, wound infections, urinary tract infection and mastitis in dogs only. All 20 isolates were resistant to clindamycin and sulphamethoxazole/trimethoprim. Nineteen were resistant to chloramphenicol, enrofloxacin, gentamicin, marbofloxacin and pradofloxacin; additionally, seven isolates were resistant to tetracycline. Fifteen isolates carried SCCmec type II-III, four isolates had type V and one harboured type IV. To date, only a few scientific papers on clinical MRSP strains isolated from the UK have been published, thus the results from this study would provide additional baseline data for further investigations.

The molecular changing mechanism of Ampicillin-Sulbactam resistant Staphylococcus aureus towards Methicillin resistant Staphylococcus aureus

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Mieke Hemiawati Satari

2005-12-01

Full Text Available The aim of this study was to determine the molecular changing of S.aureus, which is resistant to Ampicillin-Sulbactam and then become resistant to Methicillin as a result of improper dosage. The study was conducted by isolating Ampicillin-Sulbactam resistant and Methicillin Resistant S.aureus (MRSA, afterwards an amplification process was performed by PCR (Polymerase Chain Reaction. to isolate the betalactamase enzyme regulator and PBP 2a genes. The result of this research showed that there were a deletion of few amino acids from the regulator gene, and a suspicion that the DNA sequence had been substituted from PBP 2 gene into PBP 2a (gen mec. This process had formed MRSA.

Inhibitory effects of Caesalpinia sappan on growth and invasion of methicillin-resistant Staphylococcus aureus.

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Kim, Kang-Ju; Yu, Hyeon-Hee; Jeong, Seung-Il; Cha, Jung-Dan; Kim, Shin-Moo; You, Yong-Ouk

2004-03-01

In the present study, we investigated antimicrobial activity of Caesalpinia sappan against clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and effect of Caesalpinia sappan extract on the invasion of MRSA to human mucosal fibroblasts (HMFs). Chloroform, n-butanol, methanol, and aqueous extracts of the Caesalpinia sappan showed antimicrobial activity against standard methicillin-sensitive Staphylococcus aureus (MSSA) as well as MRSA. Methanol extract of Caesalpinia sappan demonstrated a higher inhibitory activity than n-butanol, chloroform, and aqueous extracts. In the checkerboard dilution method, methanol extract of Caesalpinia sappan markedly lowered the minimal inhibitory concentrations (MICs) of ampicillin and oxacillin against MRSA. To determine whether methanol extract of Caesalpinia sappan inhibits the MRSA invasion to HMFs, the cells were treated with various sub-MIC concentrations of methanol extract and bacterial invasion was assayed. MRSA invasion was notably decreased in the presence of 20-80 microg/ml of Caesalpinia sappan extract compared to the control group. The effect of Caesalpinia sappan extract on MRSA invasion appeared dose-dependent. These results suggest that methanol extract of Caesalpinia sappan may have antimicrobial activity and the potential to restore the effectiveness of beta-lactam antibiotics against MRSA, and inhibit the MRSA invasion to HMFs.

Characterization of pig-associated methicillin-resistant Staphylococcus aureus.

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Li, Jun; Jiang, Nansong; Ke, Yuebin; Feßler, Andrea T; Wang, Yang; Schwarz, Stefan; Wu, Congming

2017-03-01

Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) have been reported in various countries worldwide. However, although China is one of the biggest pig and pork producers, large-scale studies on pig-associated LA-MRSA from China are scarce. The aims of this study were to analyze 2420 non-duplicate samples collected from pigs at swine farms and slaughterhouses in different regions in China during 2014 for the prevalence of pig-associated MRSA and to determine the antimicrobial resistance pheno- and genotypes of the respective isolates. MRSA isolates were identified in 270 (11.2%) samples. The isolates were characterized by antimicrobial susceptibility testing, multilocus sequence typing (MLST), spa typing, pulsed-field gel electrophoresis (PFGE) and screening for resistance genes. All MRSA isolates belonged to the clonal complex 9 and spa type t899, but showed variable PFGE patterns. All isolates were non-susceptible to oxacillin, cefoxitin, clindamycin, chloramphenicol, florfenicol, ciprofloxacin, and valnemulin. High rates of resistance were also observed for tetracycline (99.6%), erythromycin (97.0%), quinupristin-dalfopristin (97.0%), and gentamicin (80.4%). Three linezolid-non-susceptible isolates containing the multi-resistance gene cfr and nine rifampicin-non-susceptible isolates with mutations in rpoB were detected. Resistance to β-lactams was exclusively associated with mecA, while phenicol resistance was mainly attributable to fexA, except in the three cfr-positive isolates. The pleuromutilin-lincosamide-streptogramin A resistance gene lsa(E) was identified in all MRSA isolates, and no other pleuromutilin resistance genes, except cfr in three isolates, were detected. Pigs are the most important hosts of LA-MRSA in China. Screening for pig-associated MRSA is necessary to monitor changes in epidemiology and characteristics of these important pathogens. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparative analysis of methicillin-sensitive and resistant Staphylococcus aureus exposed to emodin based on proteomic profiling.

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Ji, Xiaoyu; Liu, Xiaoqiang; Peng, Yuanxia; Zhan, Ruoting; Xu, Hui; Ge, Xijin

2017-12-09

Emodin has a strong antibacterial activity, including methicillin-resistant Staphylococcus aureus (MRSA). However, the mechanism by which emodin induces growth inhibition against MRSA remains unclear. In this study, the isobaric tags for relative and absolute quantitation (iTRAQ) proteomics approach was used to investigate the modes of action of emodin on a MRSA isolate and methicillin-sensitive S. aureus ATCC29213(MSSA). Proteomic analysis showed that expression levels of 145 and 122 proteins were changed significantly in MRSA and MSSA, respectively, after emodin treatment. Comparative analysis of the functions of differentially expressed proteins between the two strains was performed via bioinformatics tools blast2go and STRING database. Proteins related to pyruvate pathway imbalance induction, protein synthesis inhibition, and DNA synthesis suppression were found in both methicillin-sensitive and resistant strains. Moreover, Interference proteins related to membrane damage mechanism were also observed in MRSA. Our findings indicate that emodin is a potential antibacterial agent targeting MRSA via multiple mechanisms. Copyright © 2017 Elsevier Inc. All rights reserved.

Evaluation of methicillin-resistant Staphylococcus aureus skin and soft-tissue infection prevention strategies at a military training center.

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Morrison, Stephanie M; Blaesing, Carl R; Millar, Eugene V; Chukwuma, Uzo; Schlett, Carey D; Wilkins, Kenneth J; Tribble, David R; Ellis, Michael W

2013-08-01

Military trainees are at high risk for skin and soft-tissue infections (SSTIs), especially those caused by methicillin-resistant Staphylococcus aureus (MRSA). A multicomponent hygiene-based SSTI prevention strategy was implemented at a military training center. After implementation, we observed 30% and 64% reductions in overall and MRSA-associated SSTI rates, respectively.

Detection of mecA Gene Associated with Methicillin Resistant Staphylococcus aureus and its Alternatives using Nanoparticles and Chia Seeds

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M. Rajamani

2017-11-01

Full Text Available Staphylococcus aureus, a member of the family Micrococcaceae, is a Gram-positive coccus whose cells tend to occur either singly or if dividing cells do not separate, form pairs, tetrads and distinctive irregular “grape-like” structures, which is resistant to few antibiotics like Methicillin which is termed as Methicillin resistant Staphylococcus aureus. MRSA was isolated from the pus sample. Confirmation of MRSA was done by using Kirby Bauer disk method. Followed by sub culturing in Luria bertani broth and DNA isolation was performed by phenol chloroform method and confirmed by AGE (Agarose gel electrophoresis. The amplification of mecA gene thermocycler-PCR was done. Restriction fragmented linked polymorphism was done for knowing how much restriction sites are available for organism. To calculate the molecular weight of the protein SDS-PAGE (Sodium dodecyl sulphate - Polyacrylamide gel electrophoresis was performed. Followed by alternative measures was done, by using Silver nanoparticles at different concentrations and Chia seeds against MRSA.

In vitro effects of beta-lactams combined with beta-lactamase inhibitors against methicillin-resistant Staphylococcus aureus.

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Kobayashi, S; Arai, S; Hayashi, S; Sakaguchi, T

1989-01-01

The effects of combinations of beta-lactams with two beta-lactamase inhibitors, sulbactam and clavulanic acid, were determined in vitro against 22 clinical isolates of methicillin-resistant Staphylococcus aureus. Combinations of cefpirome, cefotaxime, and cefazolin with sulbactam (10 micrograms/ml) showed synergistic effects against more than 70% of the strains. Combinations of methicillin and penicillin G with sulbactam also showed synergistic effects against 50 and 68% of the strains, respectively, while cefotiam, moxalactam, flomoxef, and cefmetazole in combination with sulbactam showed such effects against only 40% or fewer. Clavulanic acid was synergistic only when combined with penicillin G, the effect probably being due to the beta-lactamase inhibition by the inhibitor. Sulbactam did not improve the antimicrobial activities of the beta-lactams against methicillin-susceptible S. aureus strains. At 42 degrees C the MICs of cefotaxime, methicillin, and flomoxef alone were markedly decreased from the values at 35 degrees C, and no synergy between these beta-lactams and sulbactam appeared. The resistance to penicillin G was not inhibited by incubation at 42 degrees C, and combinations of penicillin G with sulbactam and clavulanic acid showed synergy. The amounts of beta-lactamase produced were not related to the decreases in the MICs of the beta-lactams, except for penicillin G combined with sulbactam. Clavulanic acid showed slightly stronger beta-lactamase-inhibiting activity than sulbactam did. These results suggest that the synergy between sulbactam and the beta-lactams, except for penicillin G, may not be due to beta-lactamase inhibition but to suppression of the methicillin-resistant S. aureus-specific resistance based on other factors. PMID:2786369

Prevalence of chlorhexidine-resistant methicillin-resistant Staphylococcus aureus following prolonged exposure.

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Schlett, Carey D; Millar, Eugene V; Crawford, Katrina B; Cui, Tianyuan; Lanier, Jeffrey B; Tribble, David R; Ellis, Michael W

2014-08-01

Chlorhexidine has been increasingly utilized in outpatient settings to control methicillin-resistant Staphylococcus aureus (MRSA) outbreaks and as a component of programs for MRSA decolonization and prevention of skin and soft-tissue infections (SSTIs). The objective of this study was to determine the prevalence of chlorhexidine resistance in clinical and colonizing MRSA isolates obtained in the context of a community-based cluster-randomized controlled trial for SSTI prevention, during which 10,030 soldiers were issued chlorhexidine for body washing. We obtained epidemiological data on study participants and performed molecular analysis of MRSA isolates, including PCR assays for determinants of chlorhexidine resistance and high-level mupirocin resistance and pulsed-field gel electrophoresis (PFGE). During the study period, May 2010 to January 2012, we identified 720 MRSA isolates, of which 615 (85.4%) were available for molecular analysis, i.e., 341 clinical and 274 colonizing isolates. Overall, only 10 (1.6%) of 615 isolates were chlorhexidine resistant, including three from the chlorhexidine group and seven from nonchlorhexidine groups (P > 0.99). Five (1.5%) of the 341 clinical isolates and five (1.8%) of the 274 colonizing isolates harbored chlorhexidine resistance genes, and four (40%) of the 10 possessed genetic determinants for mupirocin resistance. All chlorhexidine-resistant isolates were USA300. The overall prevalence of chlorhexidine resistance in MRSA isolates obtained from our study participants was low. We found no association between extended chlorhexidine use and the prevalence of chlorhexidine-resistant MRSA isolates; however, continued surveillance is warranted, as this agent continues to be utilized for infection control and prevention efforts. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Methicillin-resistant Staphylococcus aureus of lineage ST398 as cause of mastitis in cows.

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Silva, N C C; Guimarães, F F; Manzi, M P; Júnior, A Fernandes; Gómez-Sanz, E; Gómez, P; Langoni, H; Rall, V L M; Torres, C

2014-12-01

The objective of this study was to analyse the prevalence and molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) in milk of cows with mastitis. The California mastitis test (CMT) was used to detect the presence of mastitis in all 100 cows of a farm in Brazil. The CMT was positive in milk of 115 mammary quarters from 36 cows (36%). MRSA isolates were recovered from 4 of these 36 cows with mastitis (11%), and they were further characterized (one MRSA/sample). The four MRSA isolates were typed as t011-ST398-agr1-SCCmecV and presented two different pulsed-field-gel-electrophoresis-ApaI patterns. These four MRSA isolates showed resistance to tetracycline, streptomycin and ciprofloxacin, carried the mecA, blaZ, tet(K), and tet(M) resistance genes, and presented the S84L and S80F amino acid substitutions in GyrA and GrlA proteins, respectively. Two ST398 isolates exhibited resistance to gentamicin and tobramycin [with aac(6)-aph(2") and ant(4)-Ia genes] and one isolate resistance to clindamycin [with lnu(B) and lsa(E) genes]; this latter isolate also carried the spectinomycin/streptomycin resistance genes spw and aadE. MRSA of lineage ST398 is worldwide spread, normally multidrug resistant and may be responsible for bovine mastitis. To our knowledge, this is the first detection of MRSA-ST398 in Brazil. Few studies on the epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) from bovine isolates have been performed in Brazil. MRSA of lineage ST398 is worldwide spread and associated with farm animals. Multidrug-resistant MRSA-ST398 isolates were recovered in 11% of mastitic cows from a single farm, with one isolate carrying the unusual lsa(E), spw and aadE genes. To our knowledge, this is the first detection of MRSA-ST398 isolates in milk samples of cows with mastitis in Brazil. © 2014 The Society for Applied Microbiology.

Antimicrobial resistance determinants in Staphylococcus spp. recovered from birds of prey in Portugal.

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Sousa, Margarida; Silva, Nuno; Igrejas, Gilberto; Silva, Filipe; Sargo, Roberto; Alegria, Nuno; Benito, Daniel; Gómez, Paula; Lozano, Carmen; Gómez-Sanz, Elena; Torres, Carmen; Caniça, Manuela; Poeta, Patrícia

2014-07-16

Antibiotic resistance among wild animals represent an emerging public health concern. The objective of this study was to analyze the staphylococcal nasal microbiota in birds of prey and their content in antimicrobial resistance determinants. Nasal samples from 16 birds of prey were collected, swabs were dipped and incubated into BHI broth [6.5% NaCl] and later seeded on manitol salt agar and oxacillin-resistance screening agar base media. Staphylococcal colonies were isolated from both media and were identified by biochemical and molecular methods. Susceptibility testing to 18 antimicrobial agents was performed by disk-diffusion method. Six of the 16 tested animals carried staphylococci (37.5%) and 7 isolates of the following species were recovered: Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus saprophyticus, Staphylococcus sciuri rodentium, Staphylococcus cohnii urealitycum, and Staphylococcus gallinarum. The S. aureus isolate was penicillin-resistant (with blaZ gene) but methicillin-susceptible and was ascribed to spa-type t012, sequence-type ST30 and agr-type III. The S. epidermidis isolate carried blaZ, mecA, mrs(A/B), mphC, tet(K), drfA, and fusC genes, ica operon, and was typed as ST35. The genes ant6'-Ia, tet(K), tet(L), dfrG, cat221, cat194, and cat223 were detected in S. saprophyticus or S. gallinarum isolates. Birds of prey seem to be a natural reservoir of S. aureus and coagulase-negative staphylococci resistant to multiple antibiotics. Due to the convergence between habitats, the contact between wildlife, other animals and humans is now more common and this involves an increased possibility of interchange of these microorganisms in the different ecosystems. Copyright © 2014 Elsevier B.V. All rights reserved.

Comparative antibacterial activity of topical antiseptic eardrops against methicillin-resistant Staphylococcus aureus and quinolone-resistant Pseudomonas aeruginosa.

Science.gov (United States)

Youn, Cha Kyung; Jang, Sook-Jin; Jo, Eu-Ri; Choi, Ji Ae; Sim, Ju-Hwan; Cho, Sung Il

2016-06-01

Aural irrigation using antiseptic solutions can be an effective medical treatment of chronic suppurative otitis media (CSOM) owing to the increasing prevalence of antibiotic-resistant CSOM infections. In the present study, we compared the antimicrobial activities of 100% Burow's solution, 50% Burow's solution, 2% acetic acid, vinegar with water (1:1), and 4% boric acid solution against methicillin-resistant Staphylococcus aureus (MRSA), methicillin-susceptible S. aureus (MSSA), quinolone-resistant Pseudomonas aeruginosa (QRPA), and quinolone-susceptible P. aeruginosa (QSPA) in vitro. We examined the antimicrobial activities of five antiseptic solutions against MRSA, MSSA, QRPA, and QSPA. The antimicrobial activities of the solutions were calculated as a percentage of the surviving microorganisms by dividing the viable count in each antiseptic solution with that in control. The time (D10 value) required for each of the five solutions to inactivate 90% of the microorganism population was also investigated. Burow's solution exhibited the highest antimicrobial activity and the lowest D10 value against MRSA, MSSA, QRPA, and QSPA, followed by 2% acetic acid, vinegar with water (1:1), and 4% boric acid solution. Our results indicate that Burow's solution has the most potent activity against bacteria including antibiotic-resistant strains. Twofold dilution of the solution is recommended to avoid ototoxicity. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Isolation of coagulase-positive staphylococci from bitches' colostrum and milk and genetic typing of methicillin-resistant Staphylococcus pseudintermedius strains.

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Rota, Ada; Corrò, Michela; Drigo, Ilenia; Bortolami, Alessio; Börjesson, Stefan

2015-07-23

Among the coagulase-positive, potentially pathogenic staphylococci, Staphylococcus pseudintermedius has been frequently isolated from bitches' milk. This organism colonizes the mammary gland or causes infection, while S. aureus has been only occasionally reported. The objective of this study was to investigate the occurrence and persistence of coagulase-positive staphylococci in the colostrum and milk of postpartum bitches, either treated or untreated with antimicrobials, and to assess the incidence, antibiotic resistance profile and genetic type of the methicillin-resistant strains. On postpartum D1, D7 and D15, drops of secretion were collected from the mammary glands of 27 postpartum bitches, nine of which were treated with antimicrobials. Coagulase-positive staphylococci were identified, antimicrobial susceptibility and the presence of mecA were tested and the genetic profile of methicillin-resistant strains was assessed. Staphylococcus pseudintermedius was the only coagulase-positive staphylococcus isolated, and its presence was detected in 21 out of 27 bitches and in 66 out of 145 swabs. In a single bitch, it caused puerperal mastitis. In untreated bitches, the frequency of isolation was lower in colostrum than in milk. All of the isolates except one were resistant to at least three antimicrobial classes, while 14 out of 66 S. pseudintermedius strains were methicillin-resistant mecA positive (MRSP) and were isolated from eight bitches housed in the same breeding kennel. A significant association was found between antimicrobial treatment and the presence of MRSP. Six of the 12 typed isolates belonged to spa-type t02 carrying SCCmec II/III, and another six were non-typeable with spa carrying SCCmec IV. The t02-SCCmec II/III isolates were sequence type (ST) 71; four NT-SCCmec IV isolates were ST258 and two were ST369. PFGE showed that isolates from the same dog had identical band patterns, while isolates from different dogs had unique band patterns. MRSP strains

Identification of methicillin-resistant Staphylococcus aureus within the Nation’s Veterans Affairs Medical Centers using natural language processing

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Jones Makoto

2012-07-01

Full Text Available Abstract Background Accurate information is needed to direct healthcare systems’ efforts to control methicillin-resistant Staphylococcus aureus (MRSA. Assembling complete and correct microbiology data is vital to understanding and addressing the multiple drug-resistant organisms in our hospitals. Methods Herein, we describe a system that securely gathers microbiology data from the Department of Veterans Affairs (VA network of databases. Using natural language processing methods, we applied an information extraction process to extract organisms and susceptibilities from the free-text data. We then validated the extraction against independently derived electronic data and expert annotation. Results We estimate that the collected microbiology data are 98.5% complete and that methicillin-resistant Staphylococcus aureus was extracted accurately 99.7% of the time. Conclusions Applying natural language processing methods to microbiology records appears to be a promising way to extract accurate and useful nosocomial pathogen surveillance data. Both scientific inquiry and the data’s reliability will be dependent on the surveillance system’s capability to compare from multiple sources and circumvent systematic error. The dataset constructed and methods used for this investigation could contribute to a comprehensive infectious disease surveillance system or other pressing needs.

Antibacterial activity of the stem bark of Tieghemella Heckelii Pierre ex. A Chev against methicillin-resistant Staphylococcus aureus.

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Kipre, B G; Guessennd, N K; Koné, M W; Gbonon, V; Coulibaly, J K; Dosso, M

2017-03-27

Tieghemella heckelii (Sapotaceae) is a medicinal plant used in Africa, particularly in Côte d'Ivoire for treating various diseases including infections. Identification of prospective antibacterial compounds from stem bark of this plant as a result of its medicinal virtue, led to screening activity against methicillin resistant bacteria. Six extracts (hexane, chloroform, ethyl acetate, ethanol, methanol and sterile distilled water) were prepared and tested on methicillin resistant Staphylococcus aureus (MRSA) using broth microdilution method for activity assessment. From this experiment, the minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of the plant extracts were determined in sterile 96-well microplates in order to search for both bacteriostatic and bactericidal effects. Afterwards, data analysis was performed using GraphPad Prism5 software (One-way ANOVA and Turkey Multiple Comparison test). The results were then presented as Mean ± SD for experiment repeated three times. Four extracts (ethyl acetate, methanol, ethanol and sterile distilled water) showed credible potency, with strong, significant, and moderate growth inhibition of the MRSA tested. The MIC values which varied from 45 μg/mL to 97 μg/mL according to microbial phenotype, resolutely established the activity of the plant extracts. Additionally, the MBC values which varied, depending on the type of bacteria strain, revealed the bacteriostatic and bactericidal effects of the active extracts against Methicillin-resistant Staphylococcus aureus. The present study is a confirmation of the therapeutic potential of Tieghemella heckelii and its promising contribution to the discovery of a novel antibacterial drug pertaining to these resistant strains.

Risk factors for developing clinical infection with methicillin-resistant Staphylococcus aureus (MRSA) amongst hospital patients initially only colonized with MRSA.

NARCIS (Netherlands)

R. Coello; J.R. Glynn (Judith); J. J. Picazo; J. Fereres; C. Gaspar

1997-01-01

textabstractIn hospital outbreaks of methicillin-resistant Staphylococcus aureus (MRSA) many patients are initially colonized without infection. The reasons why some progress to infection while others do not are not known. A cohort of 479 hospital patients, initially only colonized with MRSA, was

Community-associated methicillin-resistant Staphylococcus aureus infection in Portugal

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R. Nazareth

2012-01-01

Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA has recently emerged as a cause of community-acquired infections among individuals without risk factors. Community-associated MRSA (CA-MRSA appears to be more virulent, causing superficial mild skin and soft tissue infections to severe necrotizing fasciitis, and in rare cases, pneumonia.Community-associated MRSA was first reported in Australia in the early 80s, after almost two decades in the USA, and then in several countries in Europe, Asia and South America. No data exists in Portugal.We report the first case of CA-MRSA infection in Portugal, in a young adult with severe necrotizing pneumonia, complicated with bilateral empyema and respiratory failure. Resumo: Recentemente assistiu-se à emergência de infeções na comunidade por Staphylococcus aureus meticilina-resistente (MRSA em indivíduos sem fatores de risco. O MRSA associado à comunidade (CA-MRSA parece ser mais virulento, causando desde infeções superficiais da pele e tecidos moles até fasceíte necrosante e, raramente, pneumonia.O CA-MRSA foi inicialmente identificado na Austrália no início da década de 80 e, após cerca de duas décadas, surgiu nos EUA e em vários países da Europa, Ásia e América do Sul. Não existe informação disponível acerca da prevalência em Portugal.Os autores reportam o primeiro caso de infeção por CA-MRSA em Portugal, num adulto jovem com pneumonia necrotizante grave complicada por empiema bilateral e insuficiência respiratória. Keywords: Community-associated, MRSA, Staphylococcus aureus, Necrotizing pneumonia, Empyema, Palavras-chave: comunidade associada, MRSA, Staphylococcus aureus, pneumonia necrosante, empiema

A new multiplex PCR for easy screening of methicillin-resistant Staphylococcus aureus SCCmec types I-V

DEFF Research Database (Denmark)

Boye, Kit; Bartels, Mette Damkjær; Andersen, Ina S

2007-01-01

A multiplex PCR with four primer-pairs was designed to identify the five main known SCCmec types. A clear and easily discriminated band pattern was obtained for all five types. The SCCmec type was identified for 98% of 312 clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA......). SCCmec type IV was by far the most common SCCmec type among both hospital- and community-acquired MRSA isolates in Denmark....

Risk factors assessment for nasal colonization of Staphylococcus aureus and its methicillin resistant strains among pre-clinical medical students of Nepal.

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Ansari, Shamshul; Gautam, Rajendra; Shrestha, Sony; Ansari, Safiur Rahman; Subedi, Shankar Nanda; Chhetri, Muni Raj

2016-04-12

Staphylococcus aureus (S. aureus), a normal flora of nasal cavity, can cause minor to life threatening invasive diseases and nosocomial infections. Methicillin resistant strains of S. aureus are causing a great challenge for treatment options. Therefore, the purpose of this study was to assess the nasal carriage rate of S. aureus, its methicillin resistant strains and risk factors in medical students prior to clinical exposure. The bacterial growth of S. aureus from nasal swab culture was identified by using standard microbiological methods recommended by American Society for Microbiology. Modified Kirby-Bauer disk diffusion method was used for antibiotic susceptibility testing and methicillin resistance was confirmed using cefoxitin and oxacillin disks. D-zone test method was used to determine the inducible clindamycin resistance. Among 200 participants, nasal carriage of S. aureus was detected from 30 (15%) subjects. Upper respiratory tract infections significantly (P aureus and their methicillin resistant strains. All of the isolates were reported to be susceptible to vancomycin and teicoplanin. S. aureus strains detected from 8 (4%) students were confirmed to be methicillin resistant. The result of our study demands for strict policy to screen all the students for nasal carriage of S. aureus and its MRSA strains to minimize the transmission of this organism from community to hospital settings.

Methicillin-resistant Staphylococcus aureus in Papua New Guinea: a community nasal colonization prevalence study.

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Laman, Moses; Greenhill, Andrew; Coombs, Geoffrey W; Robinson, Owen; Pearson, Julie; Davis, Timothy M E; Manning, Laurens

2017-08-01

There are few epidemiological data available to inform a national response to community-acquired methicillin-resistant Staphylococcus aureus (MRSA) in Papua New Guinea (PNG). We performed a cross-sectional survey to determine the pattern of MRSA nasal colonization and the diversity of circulating MRSA clones among adults and adolescents in Madang Province, PNG. S. aureus nasal colonization was confirmed in 44 (17.1%) of 257 participants. Four (9.1%) isolates were methicillin resistant. Resistance to other antimicrobial agents was uncommon. Detailed molecular typing of three MRSA isolates demonstrated multiple MRSA clones in this community, of which two carried the Panton-Valentin leukocidin-associated virulence genes. MRSA is likely to account for a clinically important proportion of staphylococcal disease in PNG. There are multiple MRSA clones in PNG. Ongoing surveillance of community and invasive isolates is a critical component of an effective response to the challenge of community-acquired MRSA in this and many other resource-limited contexts. © The Author 2017. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) at ambient freshwater beaches

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Fogarty, Lisa R.; Haack, Sheridan K.; Johnson, Heather E.; Brennan, Angela K.; Isaacs, Natasha M.; Spencer, Chelsea

2015-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) are a threat to human health worldwide, and although detected at marine beaches, they have been largely unstudied at freshwater beaches. Genes indicating S. aureus (SA; femA) and methicillin resistance (mecA) were detected at 11 and 12 of 13 US Great Lakes beaches and in 18% or 27% of 287 recreational water samples, respectively. Eight beaches had mecA + femA (potential MRSA) detections. During an intensive study, higher bather numbers, staphylococci concentrations, and femA detections were found in samples collected after noon than before noon. Local population density, beach cloud cover, and beach wave height were significantly correlated with SA or MRSA detection frequency. The Panton-Valentine leukocidin gene, associated with community-acquired MRSA, was detected in 12 out of 27 potential MRSA samples. The femA gene was detected less frequently at beaches that met US enterococci criteria or EU enterococci ‘excellent’ recreational water quality, but was not related to Escherichia coli-defined criteria. Escherichia coli is often the only indicator used to determine water quality at US beaches, given the economic and healthcare burden that can be associated with infections caused by SA and MRSA, monitoring of recreational waters for non-fecal bacteria such as staphylococci and/or SA may be warranted.

Genome-wide analysis of the regulatory function mediated by the small regulatory psm-mec RNA of methicillin-resistant Staphylococcus aureus.

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Cheung, Gordon Y C; Villaruz, Amer E; Joo, Hwang-Soo; Duong, Anthony C; Yeh, Anthony J; Nguyen, Thuan H; Sturdevant, Daniel E; Queck, S Y; Otto, M

2014-07-01

Several methicillin resistance (SCCmec) clusters characteristic of hospital-associated methicillin-resistant Staphylococcus aureus (MRSA) strains harbor the psm-mec locus. In addition to encoding the cytolysin, phenol-soluble modulin (PSM)-mec, this locus has been attributed gene regulatory functions. Here we employed genome-wide transcriptional profiling to define the regulatory function of the psm-mec locus. The immune evasion factor protein A emerged as the primary conserved and strongly regulated target of psm-mec, an effect we show is mediated by the psm-mec RNA. Furthermore, the psm-mec locus exerted regulatory effects that were more moderate in extent. For example, expression of PSM-mec limited expression of mecA, thereby decreasing methicillin resistance. Our study shows that the psm-mec locus has a rare dual regulatory RNA and encoded cytolysin function. Furthermore, our findings reveal a specific mechanism underscoring the recently emerging concept that S. aureus strains balance pronounced virulence and high expression of antibiotic resistance. Published by Elsevier GmbH.

Characterisation of SCCmec elements in methicillin-resistant Staphylococcus aureus isolated from burn patients.

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Namvar, Amirmorteza Ebrahimzadeh; Afshar, Mastaneh; Asghari, Babak; Rastegar Lari, Abdolaziz

2014-06-01

Staphylococcus aureus is an important pathogen, especially in burn units all around the world. Because of the emergence of the β-lactam antibiotic-resistant strains since 1961, concern about the prevalence of methicillin-resistant S. aureus (MRSA) has increased in these units. Resistance to methicillin is mediated by penicillin-binding proteins (PBPs) that have enough affinity for binding to the β-lactam ring, but another kind of protein (PBP2α), which is encoded by the mecA gene, has a lower affinity for binding to these antibiotics. The mecA gene is transferred by SCCmec (staphylococcal cassette chromosome mec) as a mobile genetic element, exclusively found in the Staphylococcus genus. Identification of the frequency of the mecA gene, different SCCmec types and also its incidence may have benefit in surveillance prevention and control of MRSA strains in burn units. In this study, 40 S. aureus isolates were collected from patients hospitalised in Motahari burn center of Tehran, during 2012-2013. Conventional microbiological methods were applied and the confirmed isolates were stored at -20°C for molecular polymerase chain reaction (PCR) tests. The antibiotic resistance pattern was performed by disc diffusion method and finally the different SCCmec types were determined by specific primers. During this research, 40 isolates of S. aureus were collected from burn patients, of which (37.5%) of the specimens belonged to female patients and 62.5% to male patients. The aetiology of the burn was classified as follows: open flame (35%), liquid (32.5%), chemical (5%) and other (27.5%). By a disc diffusion method, no resistance pattern was observed to vancomycin and fosfomycin. Based on a multiplex PCR assay, the five different SCCmec types were detected as: 47.5% type III, 25% type IV, 10% type V, 10% type II and 7.5% type I. Copyright © 2013 Elsevier Ltd and ISBI. All rights reserved.

Draft Genome Sequences of 12 Clinical and Environmental Methicillin-Resistant Strains of Staphylococcus pseudintermedius Isolated from a Veterinary Teaching Hospital in Washington State

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Shah, Devendra H.; Jones, Lisa P.; Paul, Narayan

2018-01-01

ABSTRACT Methicillin-resistant Staphylococcus pseudintermedius (MRSP) is a globally emergent multidrug-resistant pathogen of dogs associated with nosocomial transmission in dogs and with potential zoonotic impacts. Here, we report the draft whole-genome sequences of 12 hospital-associated MRSP strains and their resistance genotypes and phenotypes. PMID:29650582

Phenotypic and molecular characteristics of methicillin-resistant Staphylococcus aureus isolates from Ekiti State, Nigeria

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Olowe OA

2013-08-01

Full Text Available Olugbenga Adekunle Olowe,1 Olayinka Oluwatoyin Kukoyi,2 Samuel Sunday Taiwo,1 Olusola Ojurongbe,1 Oluyinka Oladele Opaleye,1 Oloyede Samuel Bolaji,1 Abiodun Adebimpe Adegoke,1 Olufunmilola Bamidele Makanjuola,1 David Olusoga Ogbolu,3 Oyebode Terry Alli31Department of Medical Microbiology and Parasitology, College of Health Sciences, Ladoke Akintola University of Technology, Ogbomoso, Nigeria; 2Department of Microbiology, College of Sciences, Afe Babalola University, Ado-Ekiti, Nigeria; 3Department of Biomedical Sciences, College of Health Sciences, Lautech, Osogbo, NigeriaIntroduction: The characteristics and antimicrobial resistance profiles of Staphylococcus aureus differs according to geographical regions and in relation to antibiotic usage. The aim of this study was to determine the biochemical characteristics of the prevalent S. aureus from Ekiti State, Nigeria, and to evaluate three commonly used disk diffusion methods (cefoxitin, oxacillin, and methicillin for the detection of methicillin resistance in comparison with mecA gene detection by polymerase chain reaction.Materials and methods: A total of 208 isolates of S. aureus recovered from clinical specimens were included in this study. Standard microbiological procedures were employed in isolating the strains. Susceptibility of each isolate to methicillin (5 µg, oxacillin (1 µg, and cefoxitin (30 µg was carried out using the modified Kirby–Bauer/Clinical and Laboratory Standard Institute disk diffusion technique. They were also tested against panels of antibiotics including vancomycin. The conventional polymerase chain reaction method was used to detect the presence of the mecA gene.Results: Phenotypic resistance to methicillin, oxacillin, and cefoxitin were 32.7%, 40.3%, and 46.5%, respectively. The mecA gene was detected in 40 isolates, giving a methicillin-resistant S. aureus (MRSA prevalence of 19.2%. The S. aureus isolates were resistant to penicillin (82.7% and tetracycline

An Investigation of Antibiotic Resistance Pattern in the Strains of Methicillin-resistant Staphylococcus epidermidis Isolated From Clinical Samples in Isfahan Province, Iran

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Fahimeh Nourbakhsh

2016-08-01

Full Text Available Background and Objectives: Staphylococcus epidermidis is one of the effective factors causing nosocomial infections. This study was performed to investigate the antibiotic resistance pattern in the methicillin-resistant S. epidermidis strains isolated from clinical samples in Isfahan Province. Methods: In this descriptive cross-sectional study, 150 isolates of S. epidermidis were isolated from detected from the patients hospitalized in hospitals and treatment centers of Isfahan City. The antibiotic resistance pattern was evaluated by disk diffusion method. The presence of the gene encoding antibiotic resistance to methicillin (mec A in the isolates were investigated using PCR method. Data were analyzed with Chi-square and Fisher's exact statistical tests. Results: In this study, most isolates were related to urinary tract infections. The highest resistance was reported to penicillin (98.9%, erythromycin (89.4%, ciprofloxacin (77.7%, clindamycin (65.9%, tetracycline (63.2%, and meticillin (54%. None of the strains showed resistance to vancomycin and linezolid. Molecular studies indicated the presence of mecA gene in 76% of the studied isolates. Conclusion: According to the results of this study, vancomycin and linezolid antibiotics can be the best choice of treatment for infections caused by S. epidermidis. Also, high resistance of S. epidermidis can be a serious warning for increased multiple antibiotic resistance. Molecular studies are indicative of high sensitivity of molecular methods in the investigation of methicillin-resistant isolates.  

Evolution of community- and healthcare-associated methicillin-resistant Staphylococcus aureus☆

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Uhlemann, Anne-Catrin; Otto, Michael; Lowy, Franklin D.; DeLeo, Frank R.

2013-01-01

Staphylococcus aureus is a prominent cause of human infections globally. The high prevalence of infections is compounded by antibiotic resistance—a significant problem for treatment. Methicillin-resistant S. aureus (MRSA) is endemic in hospitals and healthcare facilities worldwide, and is an increasingly common cause of community-associated bacterial infections in industrialized countries. Although much focus is placed on the role of S. aureus as a human pathogen, it is in fact a human commensal organism that has had a relatively long coexistence with the human host. Many S. aureus infections can be explained by host susceptibility or other predisposing risk factors. On the other hand, the emergence/re-emergence of successful S. aureus clones (referred to as epidemic waves) suggests a rapid bacterial adaption and evolution, which includes the emergence of antibiotic resistance and increased virulence and/or transmissibility. It is within this context that we review our understanding of selected S. aureus epidemic waves, and highlight the use of genome sequencing as a means to better understand the evolution of each lineage. PMID:23648426

Proposal for common Nordic epidemiological terms and definitions for methicillin-resistant Staphylococcus aureus (MRSA)

DEFF Research Database (Denmark)

Skov, Robert; Gudlaugsson, Olafur; Hardardottir, Hjordis

2008-01-01

The recent increase in the incidence of methicillin-resistant Staphylococcus aureus in all the Nordic countries prompted the Scandinavian Society for Antimicrobial Chemotherapy (SSAC) to create the 'SSAC Working Party on MRSA' with the objective to identify methods to keep the invasive MRSA...... infections in the Nordic countries below 1%. The lack of common definitions was recognized as a major obstacle for a joint Nordic effort to combat MRSA. The aim of this publication is to present proposals for epidemiological definitions of individual cases, for how to report MRSA frequency per country...

Isolation of methicillin-resistant Staphylococcus aureus from small ruminants and their meat at slaughter and retail level in Greece.

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Sergelidis, D; Papadopoulos, T; Komodromos, D; Sergelidou, E; Lazou, T; Papagianni, M; Zdragas, A; Papa, A

2015-11-01

Methicillin-resistant Staphylococcus aureus (MRSA) presents major health risk for humans causing serious nosocomial and community-acquired infections. Asymptomatic food-producing animal carriers and their meat may represent potential reservoirs for human infections. The aim of this study was to investigate the prevalence of MRSA in small ruminants raised under free-range conditions and their meat at slaughter and retail level in Northern Greece. Staphylococcus aureus was isolated from 9·6% of the examined samples. All isolates were resistant at least to one antibiotic, whereas 59·3% of them were multidrug resistant (MDR) exhibiting resistance to three or more antibiotic classes. The higher resistance rates were observed against penicillin (100%), tetracycline (74%), clindamycin (59·3%) and erythromycin (51·9%). Resistance to cefoxitin was exhibited by 22·2% of the isolates, but only one isolate was found to carry the mecA gene and belonged to spa type t127. This is the first time this type of Staph. aureus is isolated in Greece from the surface of a small ruminant's carcass. The presence of multidrug resistant Staph. aureus, and especially MRSA, in small ruminants and their meat, represents a potential threat for the spread of this pathogen in the community. This study is the first report on methicillin-resistant Staphylococcus aureus in small ruminants and their meat at slaughter level in Greece, elucidating a possible vehicle food for transmission to humans. These results suggest that human or animal sources could be involved in meat contamination and thus sources of contamination require investigation to control the dispersion of MRSA in the community. © 2015 The Society for Applied Microbiology.

Potential Mechanism of Action of 3′-Demethoxy-6-O-demethyl-isoguaiacin on Methicillin Resistant Staphylococcus aureus

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Juan Manuel J. Favela-Hernández

2015-07-01

Full Text Available Bacterial infections represent one of the main threats to global public health. One of the major causative agents associated with high morbidity and mortality infections in hospitals worldwide is methicillin-resistant Staphylococcus aureus. Therefore, there is a need to develop new antibacterial agents to treat these infections, and natural products are a rich source of them. In previous studies, we reported that lignan 3′-demethoxy-6-O-demethylisoguaiacin, isolated and characterized from Larrea tridentate, showed the best activity towards methicillin-resistant S. aureus. Thus, the aim of this study was to determine the potential molecular mechanism of the antibacterial activity of 3′-demethoxy-6-O-demethylisoguaiacin against methicillin-resistant S. aureus using microarray technology. Results of microarray genome expression were validated by real-time polymerase chain reaction (RT-PCR. The genetic profile expression results showed that lignan 3′-demethoxy-6-O-demethylisoguaiacin had activity on cell membrane affecting proteins of the ATP-binding cassette (ABC transport system causing bacteria death. This molecular mechanism is not present in any antibacterial commercial drug and could be a new target for the development of novel antibacterial agents.

Zeroing in on methicillin-resistant Staphylococcus aureus: US Department of Veterans Affairs' MRSA Prevention Initiative.

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Kralovic, Stephen M; Evans, Martin E; Simbartl, Loretta A; Ambrose, Meredith; Jain, Rajiv; Roselle, Gary A

2013-05-01

Implementation of a methicillin-resistant Staphylococcus aureus (MRSA) Prevention Initiative within US Department of Veterans Affairs medical facilities was associated with a significant reduction in MRSA health care-associated infection (HAI) rates nationwide. The first 36 months of data from the Initiative were analyzed to determine how many facilities reported zero MRSA HAIs each month. From October 2007 through September 2010, there was a 37.6% increase nationwide in the number of facilities achieving zero MRSA HAIs each month. Published by Mosby, Inc.

SCC mec typing and antimicrobial resistance of methicillin-resistant Staphylococcus aureus (MRSA) from pigs of Northeast India.

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Rajkhowa, S; Sarma, D K; Pegu, S R

2016-12-01

Staphylococcus aureus is one of the most important pathogens of both humans and animal. Methicillin-resistant Staphylococcus aureus (MRSA) is an important human pathogen that causes serious infections both in hospitals and communities due to its multidrug resistance tendency. This study was undertaken to characterize the MRSA isolates from pigs and to determine the antimicrobial resistance of these isolates. Forty nine MRSA strains (one strain per positive pig) isolated from pigs of Northeast India were characterized by SCCmec typing and antimicrobial resistance. The overall prevalence of MRSA was 7.02 % with the highest prevalence recorded in pigs aged 1-3 months (P = 0.001) and in nasal samples (P = 0.005). Two SCC mec types (type III and V) were found in Indian pigs with predominance of type V. All isolates were resistant to penicillin. Seventeen resistance groups were observed where 87.75 % isolates showed multidrug resistance (showed resistance to three or more classes of antimicrobials). The most predominant resistance pattern observed was Oxytetracycline + Penicillin + Sulfadiazine + Tetracycline accounting 12.24 % of the isolates. The present study contributes to the understanding of characteristics and antimicrobial resistance of porcine MRSA isolates which in turn will help in devising strategy for the control of this pathogen. Findings of the study also throw light on multidrug resistance MRSA and emphasize the need for judicious use of antimicrobials in animal practice.

PCR-based Approaches for the Detection of Clinical Methicillin-resistant Staphylococcus aureus

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Liu, Ying; Zhang, Jiang; Ji, Yinduo

2016-01-01

Staphylococcus aureus is an important pathogen that can cause a variety of infections, including superficial and systematic infections, in humans and animals. The persistent emergence of multidrug resistant S. aureus, particularly methicillin-resistant S. aureus, has caused dramatically economic burden and concerns in the public health due to limited options of treatment of MRSA infections. In order to make a correct choice of treatment for physicians and understand the prevalence of MRSA, it is extremely critical to precisely and timely diagnose the pathogen that induces a specific infection of patients and to reveal the antibiotic resistant profile of the pathogen. In this review, we outlined different PCR-based approaches that have been successfully utilized for the rapid detection of S. aureus, including MRSA and MSSA, directly from various clinical specimens. The sensitivity and specificity of detections were pointed out. Both advantages and disadvantages of listed approaches were discussed. Importantly, an alternative approach is necessary to further confirm the detection results from the molecular diagnostic assays. PMID:27335617

Characterisation of virulence genes in methicillin susceptible and resistant Staphylococcus aureus isolates from a paediatric population in a university hospital of Medellín, Colombia

OpenAIRE

Jiménez,Judy Natalia; Ocampo,Ana María; Vanegas,Johanna Marcela; Rodríguez,Erika Andrea; Garcés,Carlos Guillermo; Patiño,Luz Adriana; Ospina,Sigifredo; Correa,Margarita María

2011-01-01

Virulence and antibiotic resistance are significant determinants of the types of infections caused by Staphylococcus aureus and paediatric groups remain among the most commonly affected populations. The goal of this study was to characterise virulence genes of methicillin-susceptible S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) strains isolated from a paediatric population of a Colombian University Hospital during 2009. Sixty MSSA and MRSA isolates were obtained from paediatric...

Response of methicillin-resistant Staphylococcus aureus to amicoumacin A.

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Amrita Lama

Full Text Available Amicoumacin A exhibits strong antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA, hence we sought to uncover its mechanism of action. Genome-wide transcriptome analysis of S. aureus COL in response to amicoumacin A showed alteration in transcription of genes specifying several cellular processes including cell envelope turnover, cross-membrane transport, virulence, metabolism, and general stress response. The most highly induced gene was lrgA, encoding an antiholin-like product, which is induced in cells undergoing a collapse of Δψ. Consistent with the notion that LrgA modulates murein hydrolase activity, COL grown in the presence of amicoumacin A showed reduced autolysis, which was primarily caused by lower hydrolase activity. To gain further insight into the mechanism of action of amicoumacin A, a whole genome comparison of wild-type COL and amicoumacin A-resistant mutants isolated by a serial passage method was carried out. Single point mutations generating codon substitutions were uncovered in ksgA (encoding RNA dimethyltransferase, fusA (elongation factor G, dnaG (primase, lacD (tagatose 1,6-bisphosphate aldolase, and SACOL0611 (a putative glycosyl transferase. The codon substitutions in EF-G that cause amicoumacin A resistance and fusidic acid resistance reside in separate domains and do not bring about cross resistance. Taken together, these results suggest that amicoumacin A might cause perturbation of the cell membrane and lead to energy dissipation. Decreased rates of cellular metabolism including protein synthesis and DNA replication in resistant strains might allow cells to compensate for membrane dysfunction and thus increase cell survivability.

Pediatric neck abscesses: No increase in methicillin-resistant Staphylococcus aureus.

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Fellner, Avital; Marom, Tal; Muallem-Kalmovich, Limor; Shlamkovitch, Nathan; Eviatar, Ephraim; Lazarovitch, Tzilia; Pitaro, Jacob

2017-10-01

Recent studies from Western countries showed an increased incidence rate of methicillin-resistant Staphylococcus aureus (MRSA) isolated from pediatric neck abscesses cultures. We sought to examine the microbiology and antibiotic susceptibility of such samples over a 10-year period, and particularly of Staphylococcus aureus (SA), in order to determine whether a similar trend exists in our institution. A retrospective chart review of children ≤18 years that underwent needle aspiration or surgical drainage of neck abscesses, including suppurative lymphadenitis, retropharyngeal abscesses, and parapharyngeal abscesses was conducted between 1/1/06-31/12/15. Sixty-two children were identified with a male predominance (34, 55%). The median age was 2 years. There were 37 (60%) suppurative lymphadenitis, 15 (24%) parapharyngeal abscess, and 10 (16%) retropharyngeal abscess cases. Twenty-nine (47%) children received antibiotic treatment prior to admission, most commonly β-lactam agents. Of them, 15 (52%) had positive cultures, including 7 (47%) with SA. On admission, 45 (73%) children had already received amoxicillin-clavulanate. Of those who did not improve, 16 (26%) received ceftriaxone and clindamycin. Twenty-one (38%) cultures were negative. The most common isolated bacteria were SA in 13 (24%), Streptococcus pyogenes in 7 (13%), and Streptococcus viridians group in 9 (16%). Of the SA isolates, there was only 1 (8%) case of MRSA; however, there were 4 (31%) clindamycin-resistant SA isolates. Unlike previously published data, there was no increase in MRSA incidence at our institution. However, the high prevalence of clindamycin-resistant SA was in line with previous reports. These findings should be considered when starting empirical therapy in pediatric neck abscesses. Copyright © 2017 Elsevier B.V. All rights reserved.

Reduced susceptibility to vancomycin and biofilm formation in methicillin-resistant Staphylococcus epidermidis isolated from blood cultures

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Luiza Pinheiro

2014-11-01

Full Text Available This study aimed to correlate the presence of ica genes, biofilm formation and antimicrobial resistance in 107 strains of Staphylococcus epidermidis isolated from blood cultures. The isolates were analysed to determine their methicillin resistance, staphylococcal cassette chromosome mec (SCCmec type, ica genes and biofilm formation and the vancomycin minimum inhibitory concentration (MIC was measured for isolates and subpopulations growing on vancomycin screen agar. The mecA gene was detected in 81.3% of the S. epidermidis isolated and 48.2% carried SCCmec type III. The complete icaADBC operon was observed in 38.3% of the isolates; of these, 58.5% produced a biofilm. Furthermore, 47.7% of the isolates grew on vancomycin screen agar, with an increase in the MIC in 75.9% of the isolates. Determination of the MIC of subpopulations revealed that 64.7% had an MIC ≥ 4 μg mL-1, including 15.7% with an MIC of 8 μg mL-1 and 2% with an MIC of 16 μg mL-1. The presence of the icaADBC operon, biofilm production and reduced susceptibility to vancomycin were associated with methicillin resistance. This study reveals a high level of methicillin resistance, biofilm formation and reduced susceptibility to vancomycin in subpopulations of S. epidermidis. These findings may explain the selection of multidrug-resistant isolates in hospital settings and the consequent failure of antimicrobial treatment.

First report in South America of companion animal colonization by the USA1100 clone of community-acquired meticillin-resistant Staphylococcus aureus (ST30) and by the European clone of methicillin-resistant Staphylococcus pseudintermedius (ST71).

Science.gov (United States)

Quitoco, Isidório Mebinda Zuco; Ramundo, Mariana Severo; Silva-Carvalho, Maria Cícera; Souza, Raquel Rodrigues; Beltrame, Cristiana Ossaille; de Oliveira, Táya Figueiredo; Araújo, Rodrigo; Del Peloso, Pedro Fernandez; Coelho, Leonardo Rocchetto; Figueiredo, Agnes Marie Sá

2013-08-27

Methicillin-resistant staphylococci can colonize and cause diseases in companion animals. Unfortunately, few molecular studies have been carried out in Brazil and other countries with the aim of characterizing these isolates. Consequently, little is known about the potential role of companion animals in transmitting these resistant bacteria to humans. In this work we searched for mecA gene among Staphylococcus isolates obtained from nasal microbiota of 130 healthy dogs and cats attended in a veterinary clinic located in the west region of Rio de Janeiro. The isolates recovered were identified to the species level and characterized using molecular tools. A community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) isolate related to USA1100 (Southwest Pacific clone) and susceptible to all non-β-lactams was detected in a cat (1.7%, 1/60). Another coagulase-positive isolate harboring mecA was recovered from a dog (1.4%, 1/70) and identified as Staphylococcus pseudintermedius (MRSP) related to the European clone (ST71). The two isolates of Staphylococcus conhii subsp. urealyticus (1.4%, 1/70 dogs and 1.7%, 1/60 cats), similarly to the MRSP isolate, also presented high-level multiresistance. The majority of the methicillin-resistant coagulase-negative staphylococci recovered were Staphylococcus saprophyticus (5.7%, 4/70 dogs and 6.7%, 4/60 cats) and all clustered into the same PFGE type. This work demonstrates that mecA-harboring Staphylococcus isolates are common members of the nasal microbiota of the healthy companion animals studied (9.2%, 12/130 animals), including some high-level multiresistant isolates of S. pseudintermedius and S. conhii subsp. urealyticus. The detection, for the first time in South America, of USA1100-related CA-MRSA and of ST71 MRSP (European clone), colonizing companion animals, is of concern. Both S. pseudintermedius and S. aureus are important agents of infections for animals. The USA1100 CA-MRSA is a causative of severe and

Draft Genome Sequence of a Sequence Type 398 Methicillin-Resistant Staphylococcus aureus Isolate from a Danish Dairy Cow with Mastitis

DEFF Research Database (Denmark)

Ronco, Troels; Stegger, Marc; Pedersen, Karl

2017-01-01

Livestock-associated (LA) methicillin-resistant Staphylococcus aureus (MRSA) strains of sequence type 398 (ST398) colonize both humans and various livestock species. In 2016, an ST398 LA-MRSA isolate (Sa52) was collected from a Danish dairy cow with mastitis, and here, we report the draft genome...

Analysis of methicillin-resistant Staphylococcus aureus by IS1181 profiling.

Science.gov (United States)

Symms, C; Cookson, B; Stanley, J; Hookey, J V

1998-06-01

Variation in the genomic location and copy number of the insertion element IS1181 in methicillin-resistant Staphylococcus aureus (MRSA) was investigated. Sixty-three isolates representing the Jevons type strain (NCTC 10442), phage-propagating strains, and epidemic strains were examined. A PCR amplicon of the insertion element was used to probe genomic restriction endonuclease digests. HindIII genomic digests gave 25 distinct IS1181 patterns, while EcoRI digests gave 20 patterns. EMRSA-01, -02, -04, -06, -07, -09, -10, -11, -13 and -14 contained the element but could not be subtyped by profiling it. EMRSA-16 did not contain IS1181, consistent with a unique evolutionary origin for this major UK epidemic strain. Marked heterogeneity was observed among isolates of EMRSA-03. Each EMRSA-03 strain examined gave a unique pattern, thereby allowing subtyping of an important epidemic phage type for the purposes of hospital cross-infection control.

Phylogeographic variation in recombination rates within a global clone of Methicillin-Resistant Staphylococcus aureus (MRSA)

DEFF Research Database (Denmark)

Castillo-Ramirez, Santiago; Corander, Jukka; Marttinen, Pekka

2012-01-01

by employing a recently developed Bayesian approach, BRATNextGen, for detecting recombination on an expanded NGS dataset of the globally disseminated methicillin-resistant Staphylococcus aureus (MRSA) clone ST239. RESULTS: The data confirm strong geographical clustering at continental, national and city scales...... that the rapid global dissemination of a single pathogenic bacterial clone results in local variation in measured recombination rates. Possible explanatory variables include the size and time since emergence of each defined sub-population (as determined by the sampling frame), variation in transmission dynamics...

[Epidemic of Staphylococcus aureus nosocomial infections resistant to methicillin in a maternity ward].

Science.gov (United States)

Le Coq, M; Simon, I; Sire, C; Tissot-Guerraz, F; Fournier, L; Aho, S; Noblot, G; Reverdy, M E; Françoise, M

2001-02-01

Methicillin-resistant Staphylococcus aureus (MRSA) nosocomial infections frequently occur in the hospital environment, but their incidence is less often observed in neonates. In the present investigation, seventeen cases were recorded over a nine-week period (two cases per week). Pulsed field gradient gel electrophoresis confirmed the clonal character of the strain. The hypothesis of manually-transmitted infection due to contamination from multiple sources was reinforced by the fact the epidemic persisted in spite of the elimination of the main human infectious source and an absence of risk factors determined by the case-control study. The role of environmental factors in the persistence of this outbreak of MRSA infection has been considered.

Origin and evolution of European community-acquired methicillin-resistant Staphylococcus aureus.

Science.gov (United States)

Stegger, Marc; Wirth, Thierry; Andersen, Paal S; Skov, Robert L; De Grassi, Anna; Simões, Patricia Martins; Tristan, Anne; Petersen, Andreas; Aziz, Maliha; Kiil, Kristoffer; Cirković, Ivana; Udo, Edet E; del Campo, Rosa; Vuopio-Varkila, Jaana; Ahmad, Norazah; Tokajian, Sima; Peters, Georg; Schaumburg, Frieder; Olsson-Liljequist, Barbro; Givskov, Michael; Driebe, Elizabeth E; Vigh, Henrik E; Shittu, Adebayo; Ramdani-Bougessa, Nadjia; Rasigade, Jean-Philippe; Price, Lance B; Vandenesch, Francois; Larsen, Anders R; Laurent, Frederic

2014-08-26

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) was recognized in Europe and worldwide in the late 1990s. Within a decade, several genetically and geographically distinct CA-MRSA lineages carrying the small SCCmec type IV and V genetic elements and the Panton-Valentine leukocidin (PVL) emerged around the world. In Europe, the predominant CA-MRSA strain belongs to clonal complex 80 (CC80) and is resistant to kanamycin/amikacin and fusidic acid. CC80 was first reported in 1993 but was relatively rare until the late 1990s. It has since been identified throughout North Africa, the Middle East, and Europe, with recent sporadic reports in sub-Saharan Africa. While strongly associated with skin and soft tissue infections, it is rarely found among asymptomatic carriers. Methicillin-sensitive S. aureus (MSSA) CC80 strains are extremely rare except in sub-Saharan Africa. In the current study, we applied whole-genome sequencing to a global collection of both MSSA and MRSA CC80 isolates. Phylogenetic analyses strongly suggest that the European epidemic CA-MRSA lineage is derived from a PVL-positive MSSA ancestor from sub-Saharan Africa. Moreover, the tree topology suggests a single acquisition of both the SCCmec element and a plasmid encoding the fusidic acid resistance determinant. Four canonical SNPs distinguish the derived CA-MRSA lineage and include a nonsynonymous mutation in accessory gene regulator C (agrC). These changes were associated with a star-like expansion into Europe, the Middle East, and North Africa in the early 1990s, including multiple cases of cross-continent imports likely driven by human migrations. With increasing levels of CA-MRSA reported from most parts of the Western world, there is a great interest in understanding the origin and factors associated with the emergence of these epidemic lineages. To trace the origin, evolution, and dissemination pattern of the European CA-MRSA clone (CC80), we sequenced a global collection

Effect of bactericidal activity of three disinfectants on methicillin-resistant Staphylococcus aureus (MRSA

Directory of Open Access Journals (Sweden)

Cesar Augusto Marchionatti Avancini

2017-05-01

Full Text Available Background and Objectives: Methicillin-resistant Staphylococcus aureus (MRSA can cause hospital-acquired infections (HA-MRSA, community- acquired ones (CA-MRSA, and infections transmitted by pets and animals raised for food production (livestock-acquired or LA-MRSA. The conduct to control the transmission of these diseases requires a careful action against the causative agents on surfaces in the environment and the choice of disinfectants and antiseptics is crucial. The objective of the present study was to evaluate the effect of the bactericidal activity of sodium hypochlorite (SH, iodophor (I and a quaternary ammonium compound (QAC, cetyl-trimethyl-ammonium chloride, commonly used in hospital and animal production settings, on 21 MRSA isolates and a control bacterium, and test the hypothesis of cross resistance of antibiotics and disinfectants. Methods: The bactericidal activity of four successive dilutions of the disinfectants was evaluated through the suspension test, using an initial inoculum population density of 107 CFU/mL, after contact times of 5, 15 and 30 minutes. Results: Five minutes of contact of SH 25 ppm, I 12.5 ppm and QAC 125 ppm sufficed to inactivate the reference bacterium S. aureus ATCC 6538 and all MRSA. Conclusions: Once the factors that influence the efficiency of disinfectants are controlled, sodium hypochlorite, iodophor and the quaternary ammonium compound are suitable for controlling MRSA in the sources of infection. No resistance relationship was observed in the methicillin-resistant isolates with these substances.

Prevention and control of methicillin-resistant Staphylococcus aureus.

LENUS (Irish Health Repository)

Humphreys, H

2009-02-01

Recent efforts to combat infections have focused on pharmaceutical interventions. However, the global spread of antimicrobial resistance calls for the reappraisal of personal and institutional hygiene. Hygiene embodies behavioural and procedural rules that prevent bacterial transmission. Consequently, the chance of spreading bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) is significantly reduced. Hygiene is part of the primacy and totality of patient care, ensuring that no harm is done. Any prevention and control strategy must be underpinned by changes in attitude, embraced by all. The major components of preventing and controlling MRSA include hand and environmental hygiene (as part of standard precautions), patient isolation, and patient\\/staff decolonization. Improving hand hygiene practice is especially important where the risk of infection is highest, e.g. in intensive care. Physical isolation has two advantages: the physical barrier interrupts transmission, and this barrier emphasizes that precautions are required. With limited isolation facilities, risk assessment should be conducted to indicate which patients should be isolated. Environmental hygiene, although important, has a lower priority than standard precautions. When a patient is ready for discharge (home) or transfer (to another healthcare facility), the overall interests of the patient should take priority. All patients should be informed of their MRSA-positive status as soon as possible. Because of increased mupirocin resistance, a selective approach to decolonization should be taken. When MRSA-positive staff are identified, restricting their professional activity will depend on the nature of their work. Finally, politicians and others need to commit to providing the necessary resources to maximize MRSA prevention and control.

Prevention and control of methicillin-resistant Staphylococcus aureus.

Science.gov (United States)

Humphreys, H; Grundmann, H; Skov, R; Lucet, J-C; Cauda, R

2009-02-01

Recent efforts to combat infections have focused on pharmaceutical interventions. However, the global spread of antimicrobial resistance calls for the reappraisal of personal and institutional hygiene. Hygiene embodies behavioural and procedural rules that prevent bacterial transmission. Consequently, the chance of spreading bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) is significantly reduced. Hygiene is part of the primacy and totality of patient care, ensuring that no harm is done. Any prevention and control strategy must be underpinned by changes in attitude, embraced by all. The major components of preventing and controlling MRSA include hand and environmental hygiene (as part of standard precautions), patient isolation, and patient/staff decolonization. Improving hand hygiene practice is especially important where the risk of infection is highest, e.g. in intensive care. Physical isolation has two advantages: the physical barrier interrupts transmission, and this barrier emphasizes that precautions are required. With limited isolation facilities, risk assessment should be conducted to indicate which patients should be isolated. Environmental hygiene, although important, has a lower priority than standard precautions. When a patient is ready for discharge (home) or transfer (to another healthcare facility), the overall interests of the patient should take priority. All patients should be informed of their MRSA-positive status as soon as possible. Because of increased mupirocin resistance, a selective approach to decolonization should be taken. When MRSA-positive staff are identified, restricting their professional activity will depend on the nature of their work. Finally, politicians and others need to commit to providing the necessary resources to maximize MRSA prevention and control.

Clinical Outcome with Oral Linezolid and Rifampin Following Recurrent Methicillin-Resistant Staphylococcus aureus Bacteremia Despite Prolonged Vancomycin Treatment

Directory of Open Access Journals (Sweden)

Jon-David Schwalm

2004-01-01

Full Text Available Drug-resistant Gram-positive bacteria, especially Staphylococcus aureus, are emerging as the predominant organisms involved in both nosocomial and community-acquired infections. Since the 1980s, vancomycin has been the first-line antibiotic used to treat methicillin-resistant S aureus. However, allergy and intolerance to vancomycin, the increasing number of vancomycin clinical failures and the existence of vancomycin intermediate-susceptible isolates of S aureus suggest that new antibiotics are needed. This paper reports the only known case of a successful clinical outcome with long term oral linezolid and rifampin therapy in the management of recurrent and persistent methicillin-resistant S aureus bacteremia with metastatic infections despite prolonged vancomycin use. More than two years since the initiation of linezolid and rifampin, the study patient has been clinically well with no evidence of adverse drug reactions including cytopenia and hepatic toxicities. Physicians must be aware of the novel developments in antibiotic therapy to treat drug-resistant bacterial infections.

Presence of a Novel DNA Methylation Enzyme in Methicillin-Resistant Staphylococcus aureus Isolates Associated with Pig Farming Leads to Uninterpretable Results in Standard Pulsed-Field Gel Electrophoresis Analysis

OpenAIRE

Bens, Corina C. P. M.; Voss, Andreas; Klaassen, Corné H. W.

2006-01-01

Genomic DNA from methicillin-resistant Staphylococcus aureus isolates recovered from pigs and their caretakers proved resistant to SmaI digestion, leading to uninterpretable results in standard pulsed-field gel electrophoresis. This is the result of a yet unknown restriction/methylation system in the genus Staphylococcus with the recognition sequence CCNGG.

A study of the effects of different disinfectants used in Riyadh hospitals and their efficacy against Methicillin Resistant Staphylococcus Aureus (MRSA)

International Nuclear Information System (INIS)

Baddour, Manal M.

2008-01-01

Methicillin resistant Staphylococcus aureus (MRSA) and the means of controlling it, continue to be of major interest to the healthcare community. The bactericidal activity of some disinfectants which are in common use in seven major tertiary care hospitals in Riyadh was tested against two control strains of S.aureus, namely MRSA ATCC 33591 and Methicillin sensitive Staphylococcus aureus (MSSA) ATCC 29213. The disinfectants tested in this study were a group used for hand antisepsis (Purell, EZ-clean, Cida stat and Manorapid Synergy) and another group used for environmental disinfection (Combi spray, Tristel fusion, Alphadine, Isopropanol, Presept and Diesin). Presept, diesin and tristel fusion had a remarkable effect on the tested strains, both methicillin sensitive and methicillin resistant. There was hardly any noticeable difference between the effects on either (P>0.05). On the other hand, Purell and EZ-clean and Manorapid Synergy hand rubs had a relatively weak action after 15 and 30 minutes while their effect was better after 1 and 2 hours. There was no observable differences between their effects on MRSA or MSSA, P>0.05. Cita stat had a remarkably pronounced effect against both MRSA and MSSA. Contrary to some previous reports, this study has proven also that chlorhexidine and quaternary ammonium compounds show comparable efficacy against both MRSA and MSSA. (author)

Occurrence of nosocomial methicillin-resistant Staphylococcus aureus as a marker for transmission in a surgical intensive care unit in China

NARCIS (Netherlands)

Chen, Yong; Zhao, Wei; Liu, Hui; Song, Qing; Wang, Yan; Zhao, Jingya; Zheng, Dongyu; Han, Xuelin; Hu, Xiaohua; Grundmann, Hajo; Han, Li

In 2008, an intensive care unit (ICU) in a large Chinese hospital was moved from a 6-bed old ward to a 20-bed new ward. After the move, the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in patients and environmental sites decreased significantly, but the number of ICU-acquired

Transmission Dynamics of Methicillin-Resistant Staphylococcus aureus in Pigs

Science.gov (United States)

Crombé, Florence; Argudín, M. Angeles; Vanderhaeghen, Wannes; Hermans, Katleen; Haesebrouck, Freddy; Butaye, Patrick

2013-01-01

From the mid-2000s on, numerous studies have shown that methicillin-resistant Staphylococcus aureus (MRSA), renowned as human pathogen, has a reservoir in pigs and other livestock. In Europe and North America, clonal complex (CC) 398 appears to be the predominant lineage involved. Especially worrisome is its capacity to contaminate humans in close contact with affected animals. Indeed, the typical multi-resistant phenotype of MRSA CC398 and its observed ability of easily acquiring genetic material suggests that MRSA CC398 strains with an increased virulence potential may emerge, for which few therapeutic options would remain. This questions the need to implement interventions to control the presence and spread of MRSA CC398 among pigs. MRSA CC398 shows a high but not fully understood transmission potential in the pig population and is able to persist within that population. Although direct contact is probably the main route for MRSA transmission between pigs, also environmental contamination, the presence of other livestock, the herd size, and farm management are factors that may be involved in the dissemination of MRSA CC398. The current review aims at summarizing the research that has so far been done on the transmission dynamics and risk factors for introduction and persistence of MRSA CC398 in farms. PMID:23518663

Radiological findings of community-acquired methicillin-resistant and methicillin-susceptible staphylococcus aureus pediatric pneumonia in Hawaii

International Nuclear Information System (INIS)

Erdem, Guliz; Bergert, Lora; Len, Kyra; Melish, Marian; Kon, Kevin; DiMauro, Robert

2010-01-01

Community-acquired Staphylococcus aureus (CA-SA) infections are common among pediatric patients in Hawaii. We wanted to characterize the radiological features of methicillin-susceptible (CA-MSSA) and methicillin-resistant (CA-MRSA) staphylococcal pneumonia in Hawaiian children. We retrospectively reviewed medical records and imaging studies of children with SA pneumonia identified from 1996 through 2007. Of 40 children, 26 (65%) had CA-MRSA pneumonia and 14 patients (35%) had CA-MSSA pneumonia. CA-MRSA patients were significantly younger than CA-MSSA patients (65% younger than 1 year vs. 36% older). In a majority (62%) of CA-MRSA patients, the consolidation was unilateral; in most of the CA-MSSA cases (79%), the consolidation was bilateral. Fifty percent of the patients with CA-MRSA and 21% of those with CA-MSSA had pneumatoceles (P = 0.1). CA-MRSA patients more commonly had pleural effusions (85% vs. 64% for CA-MSSA) and pleural thickening (50% vs. 36% for CA-MSSA). This case series describes the radiologic characteristics of CA-MRSA and CA-MSSA pneumonia in children in a highly endemic area. We found that CA-MRSA pneumonias are unilateral in a majority of pediatric pneumonia cases, are more common in children 1 year or younger, and have higher rates of complications in comparison to CA-MSSA patients. (orig.)

Radiological findings of community-acquired methicillin-resistant and methicillin-susceptible staphylococcus aureus pediatric pneumonia in Hawaii

Energy Technology Data Exchange (ETDEWEB)

Erdem, Guliz; Bergert, Lora; Len, Kyra; Melish, Marian [University of Hawaii, John A. Burns School of Medicine, Department of Pediatrics, Honolulu, HI (United States); Kon, Kevin; DiMauro, Robert [Kapiolani Medical Center for Women and Children, Department of Radiology, Honolulu, HI (United States)

2010-11-15

Community-acquired Staphylococcus aureus (CA-SA) infections are common among pediatric patients in Hawaii. We wanted to characterize the radiological features of methicillin-susceptible (CA-MSSA) and methicillin-resistant (CA-MRSA) staphylococcal pneumonia in Hawaiian children. We retrospectively reviewed medical records and imaging studies of children with SA pneumonia identified from 1996 through 2007. Of 40 children, 26 (65%) had CA-MRSA pneumonia and 14 patients (35%) had CA-MSSA pneumonia. CA-MRSA patients were significantly younger than CA-MSSA patients (65% younger than 1 year vs. 36% older). In a majority (62%) of CA-MRSA patients, the consolidation was unilateral; in most of the CA-MSSA cases (79%), the consolidation was bilateral. Fifty percent of the patients with CA-MRSA and 21% of those with CA-MSSA had pneumatoceles (P = 0.1). CA-MRSA patients more commonly had pleural effusions (85% vs. 64% for CA-MSSA) and pleural thickening (50% vs. 36% for CA-MSSA). This case series describes the radiologic characteristics of CA-MRSA and CA-MSSA pneumonia in children in a highly endemic area. We found that CA-MRSA pneumonias are unilateral in a majority of pediatric pneumonia cases, are more common in children 1 year or younger, and have higher rates of complications in comparison to CA-MSSA patients. (orig.)

Horizontal infection control strategy decreases methicillin-resistant Staphylococcus aureus infection and eliminates bacteremia in a surgical ICU without active surveillance.

Science.gov (United States)

Traa, Maria X; Barboza, Lorena; Doron, Shira; Snydman, David R; Noubary, Farzad; Nasraway, Stanley A

2014-10-01

Methicillin-resistant Staphylococcus aureus infection is a significant contributor to morbidity and mortality in hospitalized patients worldwide. Numerous healthcare bodies in Europe and the United States have championed active surveillance per the "search and destroy" model. However, this strategy is associated with significant economic, logistical, and patient costs without any impact on other hospital-acquired pathogens. We evaluated whether horizontal infection control strategies could decrease the prevalence of methicillin-resistant S. aureus infection in the ICU, without the need for active surveillance. Retrospective, observational study in the surgical ICU of a tertiary care medical center in Boston, MA, from 2005 to 2012. A total of 6,697 patients in the surgical ICU. Evidence-based infection prevention strategies were implemented in an iterative fashion, including 1) hand hygiene program with refresher education campaign, 2) chlorhexidine oral hygiene program, 3) chlorhexidine bathing, 4) catheter-associated bloodstream infection program, and 5) daily goals sheets. The prevalence of methicillin-resistant S. aureus infection fell from 2.66 to 0.69 per 1,000 patient days from 2005 to 2012, an average decrease of 21% per year. The biggest decline in rate of infection was detected in 2008, which may suggest that the catheter-associated bloodstream infection prevention program was particularly effective. Among 4,478 surgical ICU admissions over the last 5 years, not a single case of methicillin-resistant S. aureus bacteremia was observed. Aggressive multifaceted horizontal infection control is an effective strategy for reducing the prevalence of methicillin-resistant S. aureus infection and eliminating methicillin-resistant S. aureus bacteremia in the ICU without the need for active surveillance and decontamination.

[Change in drug resistance of Staphylococcus aureus].

Science.gov (United States)

Lin, Yan; Liu, Yan; Luo, Yan-Ping; Liu, Chang-Ting

2013-11-01

To analyze the change in drug resistance of Staphylococcus aureus (SAU) in the PLA general hospital from January 2008 to December 2012, and to provide solid evidence to support the rational use of antibiotics for clinical applications. The SAU strains isolated from clinical samples in the hospital were collected and subjected to the Kirby-Bauer disk diffusion test. The results were assessed based on the 2002 American National Committee for Clinical Laboratory Standards (NCCLS) guidelines. SAU strains were mainly isolated from sputum, urine, blood and wound excreta and distributed in penology, neurology wards, orthopedics and surgery ICU wards. Except for glycopeptide drugs, methicillin-resistant Staphylococcus aureus (MRSA) had a higher drug resistance rate than those of the other drugs and had significantly more resistance than methicillin-sensitive Staphylococcus aureus (MSSA) (P resistance, we discovered a gradual increase in drug resistance to fourteen test drugs during the last five years. Drug resistance rate of SAU stayed at a higher level over the last five years; moreover, the detection ratio of MRSA keeps rising year by year. It is crucial for physicians to use antibiotics rationally and monitor the change in drug resistance in a dynamic way.

Persistence of Livestock-Associated Methicillin-Resistant Staphylococcus aureus in Field Workers after Short-Term Occupational Exposure to Pigs and Veal Calves

NARCIS (Netherlands)

van Cleef, B.A.G.L.; Graveland, H.; Haenen, A.P.J.; van de Giessen, A.W.; Heederik, D.; Wagenaar, J.A.; Kluytmans, J.A.J.W.

2011-01-01

The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) carriage in pig and veal calf farmers in the Netherlands is estimated at 25 to 35%. However, no information is available about MRSA carriage in humans after short-term occupational exposure to pigs or veal calves. This study

The action of NIR (808nm) laser radiation and gold nanorods labeled with IgA and IgG human antibodies on methicillin-resistant and methicillin sensitive strains of Staphylococcus aureus

Science.gov (United States)

Tuchina, Elena S.; Petrov, Pavel O.; Ratto, Fulvio; Centi, Sonia; Pini, Roberto; Tuchin, Valery V.

2015-03-01

The effect of NIR laser radiation (808 nm) on methicillin-sensitive and methicillin resistant strains of Staphylococcus aureus incubated with gold nanorods is studied. Nanorods having length of 44 (± 4) nm and diameter of 10 (± 3) nm with the absorption maximum in the NIR (800 nm), functionalized with human immunoglobulins IgA and IgG, were synthesized and used in the studies. The killing ability up to 97% of the microorganism populations by using this nanotechnology was shown.

Screening agars for MRSA: evaluation of a stepwise diagnostic approach with two different selective agars for the screening for methicillin-resistant Staphylococcus aureus (MRSA).

Science.gov (United States)

Micheel, Volker; Hogan, Benedikt; Köller, Thomas; Warnke, Philipp; Crusius, Sabine; Hinz, Rebecca; Hagen, Ralf Matthias; Schwarz, Norbert Georg; Frickmann, Hagen

2015-01-01

Colonization with methicillin-resistant Staphylococcus aureus (MRSA) poses a hygiene risk that does not spare field hospitals or military medical field camps during military deployments. Diagnostic options for unambiguously identifying MRSA isolates are usually scarce in military environments. In this study, we assessed the stepwise application of two different selective agars for the specific identification of MRSA in screening analyses. Nasal swabs from 1541 volunteers were subjected to thioglycollate broth enrichment and subsequently screened on CHROMagar MRSA selective agar for the identification of MRSA. The MRSA identity of suspicious-looking colonies was confirmed afterwards or excluded by another selective agar, chromID MRSA. All isolates from the selective agars with MRSA-specific colony morphology were identified by biochemical methods and mass spectrometry. The initial CHROMagar MRSA screening identified suspicious colonies in 36 out of 1541 samples. A total of 25 of these 36 isolates showed MRSA-like growth on chromID agar. Out of these 25 isolates, 24 were confirmed as MRSA, while one isolate was identified as Staphylococcus kloosii. From the 11 strains that did not show suspicious growth on chromID agar, 3 were methicillin-sensitive Staphylococcus aureus (MSSA, with one instance of co-colonization with Corynebacterium spp.), 2 were confirmed as MRSA (with 1 instance of co-colonization with MSSA), 2 were lost during passaging and could not be re-cultured, one could not be identified by the applied approaches, and the remaining 3 strains were identified as Staphylococcus saprophyticus, Staphylococcus hominis (co-colonized with Macrococcus caseolyticus) and Staphylococcus cohnii, respectively. The application of the selective agar CHROMagar MRSA alone proved to be too non-specific to allow for a reliable diagnosis of the presence of MRSA. The combined use of two selective agars in a stepwise approach reduced this non-specificity with an acceptably low

Isolation and molecular characterization of methicillin-resistant Staphylococcus aureus from public transport.

Science.gov (United States)

Iwao, Yasuhisa; Yabe, Shizuka; Takano, Tomomi; Higuchi, Wataru; Nishiyama, Akihito; Yamamoto, Tatsuo

2012-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) not only causes disease in hospitals, but also in the community. The characteristics of MRSA transmission in the environment remain uncertain. In this study, MRSA were isolated from public transport in Tokyo and Niigata, Japan. Of 349 trains examined, eight (2.3%) were positive for MRSA. The MRSA isolated belonged to sequence types (STs) 5, 8, 88, and 89, and included community infection-associated ST8 MRSA (with novel type IV staphylococcal cassette chromosome mec) and the ST5 New York/Japan hospital clone. The data indicate that public transport could contribute to the spread of community-acquired MRSA, and awareness of this mode of transmission is necessary. © 2012 The Societies and Blackwell Publishing Asia Pty Ltd.

Retail ready-to-eat food as a potential vehicle for Staphylococcus spp. harboring antibiotic resistance genes.

Science.gov (United States)

Chajęcka-Wierzchowska, Wioleta; Zadernowska, Anna; Nalepa, Beata; Sierpińska, Magda; Laniewska-Trokenheim, Lucja

2014-06-01

Ready-to-eat (RTE) food, which does not need thermal processing before consumption, could be a vehicle for the spread of antibiotic-resistant microorganisms. As part of general microbiological safety checks, staphylococci are routinely enumerated in these kinds of foods. However, the presence of antibiotic-resistant staphylococci in RTE food is not routinely investigated, and data are only available from a small number of studies. The present study evaluated the pheno- and genotypical antimicrobial resistance profile of Staphylococcus spp. isolated from 858 RTE foods (cheeses, cured meats, sausages, smoked fishes, salads). Of 113 strains isolated, S. aureus was the most prevalent species, followed by S. xylosus, S. saprophyticus, and S. epidermidis. More than half (54.9%) of the isolates were resistant to at least one class of tested antibiotic; of these, 35.4% of the strains were classified as multidrug resistant. Most of the isolates were resistant to cefoxitin (49.6%), followed by clindamycin (39.3%), tigecycline (27.4%), quinupristin-dalfopristin (22.2%), rifampin (20.5%), tetracycline (17.9%), and erythromycin (8.5%). All methicillin-resistant staphylococci harbored the mecA gene. Among the isolates resistant to at least one antibiotic, 38 harbored tetracycline resistance determinant tet (M), 24 harbored tet (L), and 9 harbored tet (K). Of the isolates positive for tet (M) genes, 34.2% were positive for the Tn916-Tn1545-like integrase family gene. Our results indicated that retail RTE food could be considered an important route for the transmission of antibiotic-resistant bacteria harboring multiple antibiotic resistance genes.

Potential Mechanism of Action of 3′-Demethoxy-6-O-demethyl-isoguaiacin on Methicillin Resistant Staphylococcus aureus

OpenAIRE

Favela-Hernández, Juan; Clemente-Soto, Aldo; Balderas-Rentería, Isaías; Garza-González, Elvira; Camacho-Corona, María

2015-01-01

Bacterial infections represent one of the main threats to global public health. One of the major causative agents associated with high morbidity and mortality infections in hospitals worldwide is methicillin-resistant Staphylococcus aureus. Therefore, there is a need to develop new antibacterial agents to treat these infections, and natural products are a rich source of them. In previous studies, we reported that lignan 3′-demethoxy-6-O-demethylisoguaiacin, isolated and characterized from L...

Antimicrobial susceptibility of microorganisms isolated from sputum culture of patients with cystic fibrosis: Methicillin-resistant Staphylococcus aureus as a serious concern.

Science.gov (United States)

Mazloomi Nobandegani, Narges; Mahmoudi, Shima; Pourakbari, Babak; Hosseinpour Sadeghi, Reihaneh; Najafi Sani, Mehri; Farahmand, Fateme; Motamed, Farzaneh; Nabavizadeh Rafsanjani, Raheleh; Mamishi, Setareh

2016-11-01

Infection is a major cause of morbidity and mortality in patients with cystic fibrosis (CF). Antimicrobial resistance of the bacterial spp. particularly methicillin resistance in Staphylococcus aureus has caused a lot of attention. The aim of this study was to describe the prevalence of S. aureus, Pseudomonas aeruginosa and Burkholderia cepacia-complex as well as their antimicrobial susceptibility patterns in CF patients in an Iranian referral pediatrics Hospital. From March 2011 until February 2012, 172 samples were collected at the Children Medical Center (CMC), an Iranian referral hospital in Tehran, Iran. Sputum specimens were cultured for the following bacterial pathogens: P. aeruginosa, S. aureus, B. cepacia complex. Antimicrobial susceptibility was performed according to the Clinical Laboratory Standards Institute recommendations. In our study, 54% of the patients (n = 93) harbored at least once S. aureus, 30% (n = 52) P. aeruginosa, and 2% (n = 3) Burkholderia cepacia. In 40 patients (23%), none of these organisms was grown. An increasing colonization rate of P. aeruginosa in the second decade of life was found. In contrast, the colonization rate of S. aureus was constant in both decades of life. Methicillin resistant S. aureus (MRSA) was detected in 40 isolates (43%). Among MRSA, no resistance against vancomycin, linezolid and quinupristin/dalfopristin occurred. The susceptibility of P. aeruginosa isolates to meropenem, imipenem, doripenem, levofloxacin and polymixin B were more than 90%. The prevalence of MRSA has been rising. Since its impact on clinical outcomes, optimal prevention and treatment strategies are unclear, further studies to expand the knowledge about the infection control strategies and MRSA treatment are highly recommended. Copyright © 2016 Elsevier Ltd. All rights reserved.

Public transport as a reservoir of methicillin-resistant staphylococci.

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Stepanović, S; Cirković, I; Djukić, S; Vuković, D; Svabić-Vlahović, M

2008-10-01

The aim of this study was to explore the occurrence of methicillin-resistant staphylococci in a large urban public transport system. Samples were taken from hand rails, which passengers hold onto when they are standing. In total, 1400 swabs taken from 55 vehicles (trolleybuses, trams and buses) were examined. As many as 30.1% samples were positive for the presence of methicillin-resistant coagulase-negative staphylococci (MRCoNS), but none for methicillin-resistant Staphylococcus aureus (MRSA). MRCoNS were isolated from all 55 vehicles. Nearly 50% of MRCoNS isolates displayed resistance not only to beta-lactams, but at least to two or more other classes of antimicrobials as well. This study demonstrated widespread occurrence of MRCoNS on hand rails in public transport vehicles. MRSA was not detected. The recovery of methicillin-resistant staphylococci from public transport system implies a potential risk for transmission of these bacteria in an out-hospital environment.

Antimicrobial sensitivity profile of Staphylococcus spp. Isolated from clinical mastitis

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Thamires Martins

2012-12-01

Full Text Available Inflammation of the mammary gland, which is also known as mastitis, occupies a prominent place among the diseases that affect dairy cattle, having a great economic importance in the dairy sector. Mastitis may have different origins, however, infectious mastitis is the most frequent and represents a risk to public health due to the propagation of microorganisms through milk. Staphylococcus spp. are considered the microorganisms that cause the greatest losses in milk production, being that Staphylococcus aureus is the pathogen of major importance because they present high resistence to antimicrobials. Empirical treatment, without prior identification of the pathogens and their resistance profile, may contribute to the emergence of multidrug-resistant strains and risk the efficiency of the antimicrobial. In that scenery, the study aimed to evaluate the resistance profile of Staphylococcus spp. against some antimicrobials used in the treatment of cows with clinical mastitis. The study was conducted on a property in the state of São Paulo from January 2011 to June 2012. We evaluated 29 lactating cows that present clinical mastitis in, at least, one mammary quarter. The diagnosis of clinical mastitis was performed by evaluating the clinical signs and also by Tamis test. Samples of milk from mammary quarters were collected aseptically in sterile tubes for microbiological evaluation. Microorganisms were isolated on sheep blood agar 5% and Sabouraud agar with chloramphenicol. The sensitivity profile of Staphylococcus spp. to the antibiotics ampicillin, cephalexin, ceftiofur, cefaclor, gentamicin, kanamycin, neomycin, penicillin G and oxacillin, was tested by disk diffusion test on Mueller-Hinton agar. From a total of 106 samples of milk analyzed, 64 (60.38% presented microbiological growth, being observed isolation of Streptococcus spp. 29 (34.52%, Staphylococcus spp. 28 (33.33%, Corynebacterium spp. 17 (20.24%, filamentous fungi 4 (4.76%, yeast 4 (4

Genotyping of Methicillin Resistant Staphylococcus aureus Strains Isolated from Hospitalized Children

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Mouna Ben Nejma

2014-01-01

Full Text Available Community associated methicillin resistant Staphylococcus aureus (CA-MRSA is an emerging pathogen increasingly reported to cause skin and soft tissue infections for children. The emergence of highly virulencet CA-MRSA strains in the immunodeficiency of young children seemed to be the basic explanation of the increased incidence of CA-MRSA infections among this population. The subjects of this study were 8 patients hospitalized in the Pediatric Department at the University Hospital of Monastir. The patients were young children (aged from 12 days to 18 months who were suffering from MRSA skin infections; two of them had the infections within 72 h of their admission. The isolates were classified as community isolates as they all carried the staphylococcal cassette chromosome mec (SCCmec IV and pvl genes. Epidemiological techniques, pulsed-field gel electrophoresis (PFGE and multilocus sequence typing (MLST, were applied to investigate CA-MRSA strains. Analysis of molecular data revealed that MRSA strains were related according to PFGE patterns and they belonged to a single clone ST80. Antimicrobial susceptibility tests showed that all strains were resistant to kanamycin and 2 strains were resistant to erythromycin.

Introduction of a hydrolysis probe PCR assay for high-throughput screening of methicillin-resistant Staphylococcus aureus with the ability to include or exclude detection of Staphylococcus argenteus.

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Bogestam, Katja; Vondracek, Martin; Karlsson, Mattias; Fang, Hong; Giske, Christian G

2018-01-01

Many countries using sensitive screening methods for detection of carriage of methicillin-resistant Staphylococcus aureus (MRSA) have a sustained low incidence of MRSA infections. For diagnostic laboratories with high sample volumes, MRSA screening requires stability, low maintenance and high performance at a low cost. Herein we designed oligonucleotides for a new nuc targeted hydrolysis probe PCR to replace the standard in-house nuc SybrGreen PCR assay. This new, more time-efficient, PCR assay resulted in a 40% increase in daily sample capacity, with maintained high specificity and sensitivity. The assay was also able to detect Staphylococcus aureus clonal cluster 75 (CC75) lineage strains, recently re-classified as Staphylococcus argenteus, with a sensitivity considerably increased compared to our previous assay. While awaiting consensus if the CC75 lineage of S. aureus should be considered as S. argenteus, and whether methicillin-resistant S. argenteus should be included in the MRSA definition, many diagnostic laboratories need to update their MRSA assay sensitivity/specificity towards this lineage/species. The MRSA screening assay presented in this manuscript is comprised of nuc oligonucleotides separately targeting S. aureus and CC75 lineage strains/S. argenteus, thus providing high user flexibility for the detection of CC75 lineage strains/S. argenteus.

Community-acquired necrotizing pneumonia caused by methicillin-resistant Staphylococcus aureus ST30-SCCmecIVc-spat019-PVL positive in San Antonio de Areco, Argentina

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Silvina Fernández

2015-03-01

Full Text Available Community-acquired methicillin-resistant Staphylococcus aureus is the first cause of skin and soft tissue infections, but can also produce severe diseases such as bacteremia, osteomyelitis and necrotizing pneumonia. Some S. aureus lineages have been described in cases of necrotizing pneumonia worldwide, usually in young, previously healthy patients. In this work, we describe a fatal case of necrotizing pneumonia due to community-acquired methicillin-resistant S. aureus clone ST30-SCCmecIVc-spat019-PVL positive in an immunocompetent adult patient.

Staphylococcus aureus ocular infection: methicillin-resistance, clinical features, and antibiotic susceptibilities.

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Chih-Chun Chuang

Full Text Available BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA infection is an important public health issue. The study aimed to determine the prevalence of ocular infections caused by MRSA and to identify the clinical characteristics and antibiotic susceptibility of ocular MRSA infections by comparing those of ocular methicillin-sensitive S. aureus (MSSA infections. METHODOLOGY/PRINCIPAL FINDINGS: The medical records of the patients (n = 519 with culture-proven S. aureus ocular infections seen between January 1, 1999 and December 31, 2008 in Chang Gung Memorial Hospital were retrospectively reviewed. Two hundred and seventy-four patients with MRSA and 245 with MSSA ocular infections were identified. The average rate of MRSA in S. aureus infections was 52.8% and the trend was stable over the ten years (P value for trend  = 0.228. MRSA ocular infections were significantly more common among the patients with healthcare exposure (P = 0.024, but 66.1% (181/274 patients with MRSA ocular infections had no healthcare exposure. The most common clinical presentation for both MRSA and MSSA ocular infections was keratitis; MRSA and MSSA caused a similar disease spectrum except for lid infections. MRSA was significantly more resistant than MSSA to clindamycin, erythromycin and sulfamethoxazole/trimethoprim (all P<0.001. CONCLUSIONS/SIGNIFICANCE: We demonstrated a paralleled trend of ocular MRSA infection in a highly prevalent MRSA country by hospital-based survey. Except for lid disorder, MRSA shared similar spectrum of ocular pathology with MSSA. Since S. aureus is a common ocular pathogen, our results raise clinician's attention to the existence of highly prevalent MRSA.

Healthcare Associated Infections of Methicillin-Resistant Staphylococcus aureus: A Case-Control-Control Study.

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Zhenjiang Yao

Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA is one of the most widespread and dangerous pathogens in healthcare settings. We carried out this case-control-control study at a tertiary care hospital in Guangzhou, China, to examine the antimicrobial susceptibility patterns, risk factors and clinical outcomes of MRSA infections.A total of 57 MRSA patients, 116 methicillin-susceptible Staphylococcus aureus (MSSA patients and 102 S. aureus negative patients were included in this study. We applied the disk diffusion method to compare the antimicrobial susceptibilities of 18 antibiotics between MRSA and MSSA isolates. Risk factors of MRSA infections were evaluated using univariate and multivariate logistic regression models. We used Cox proportional hazards models and logistic regression analysis to assess the hospital stay duration and fatality for patients with MRSA infections.The MRSA group had significantly higher resistance rates for most drugs tested compared with the MSSA group. Using MSSA patients as controls, the following independent risk factors of MRSA infections were identified: 3 or more prior hospitalizations (OR 2.8, 95% CI 1.3-5.8, P = 0.007, chronic obstructive pulmonary disease (OR 5.9, 95% CI 1.7-20.7, P = 0.006, and use of a respirator (OR 3.6, 95% CI 1.0-12.9, P = 0.046. With the S. aureus negative patients as controls, use of a respirator (OR 3.8, 95% CI 1.0-13.9, P = 0.047 and tracheal intubation (OR 8.2, 95% CI 1.5-45.1, P = 0.016 were significant risk factors for MRSA infections. MRSA patients had a longer hospital stay duration and higher fatality in comparison with those in the two control groups.MRSA infections substantially increase hospital stay duration and fatality. Thus, MRSA infections are serious issues in this healthcare setting and should receive more attention from clinicians.

The effect of antimicrobial photodynamic therapy on the expression of novel methicillin resistance markers determined using cDNA-AFLP approach in Staphylococcus aureus.

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Hoorijani, Mohammad Neshvan; Rostami, Hosein; Pourhajibagher, Maryam; Chiniforush, Nasim; Heidari, Mansour; Pourakbari, Babak; Kazemian, Hossein; Davari, Kambiz; Amini, Vahid; Raoofian, Reza; Bahador, Abbas

2017-09-01

Widespread methicillin resistant Staphylococcus aureus (MRSA) and absence of effective antimicrobial agents has led to limited therapeutic options for treating MRSA infection. We aimed to evaluate the effect of antimicrobial photodynamic therapy (aPDT) on the expression of novel identified methicillin resistance markers (NIMRMs) in S. aureus using complementary DNA-Amplified Fragment Length Polymorphism (cDNA-AFLP) approaches to address the therapeutic alternatives for MRSA infections. We used cDNA-AFLP to compare MRSA and methicillin susceptible S. aureus (MSSA) for identification of target genes implicated in methicillin resistance. To determine the sub-lethal aPDT (sPDT), MRSA and MSSA clinical isolates photosensitized with toluidine blue O (TBO), and then were irradiated with diode laser. After sPDT, the colony forming units/mL was quantified. Antimicrobial susceptibility against methicillin was assessed for cell-surviving aPDT. Effects of sPDT on the expression of NIMRMs were evaluated by real-time quantitative reverse transcription PCR. According to our results, serine hydrolase family protein (Shfp) encoding gene and a gene encoding a conserved hypothetical protein (Chp) were implicated in methicillin resistance in MRSA. sPDT reduced the minimum inhibitory concentrations of methicillin by 3-fold in MRSA. sPDT could lead to about 10- and 6.2- fold suppression of expression of the Chp and Shfp encoding genes, respectively. sPDT would lead to reduction in resistance to methicillin of MRSA in surviving cells by suppressing the expression of the Shfp and Chp encoding genes associated with methicillin resistance. This may have potential implications of aPDT for the treatment of MRSA infections. Copyright © 2017 Elsevier B.V. All rights reserved.

Diversity of staphylococcal cassette chromosome mec structures in methicillin-resistant Staphylococcus epidermidis and Staphylococcus haemolyticus strains among outpatients from four countries.

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Ruppé, Etienne; Barbier, François; Mesli, Yasmine; Maiga, Aminata; Cojocaru, Radu; Benkhalfat, Mokhtar; Benchouk, Samia; Hassaine, Hafida; Maiga, Ibrahim; Diallo, Amadou; Koumaré, Abdel Karim; Ouattara, Kalilou; Soumaré, Sambou; Dufourcq, Jean-Baptiste; Nareth, Chhor; Sarthou, Jean-Louis; Andremont, Antoine; Ruimy, Raymond

2009-02-01

In staphylococci, methicillin (meticillin) resistance (MR) is mediated by the acquisition of the mecA gene, which is carried on the size and composition variable staphylococcal cassette chromosome mec (SCCmec). MR has been extensively studied in Staphylococcus aureus, but little is known about MR coagulase-negative staphylococci (MR-CoNS). Here, we describe the diversity of SCCmec structures in MR-CoNS from outpatients living in countries with contrasting environments: Algeria, Mali, Moldova, and Cambodia. Their MR-CoNS nasal carriage rates were 29, 17, 11, and 31%, respectively. Ninety-six MR-CoNS strains, comprising 75 (78%) Staphylococcus epidermidis strains, 19 (20%) Staphylococcus haemolyticus strains, 1 (1%) Staphylococcus hominis strain, and 1 (1%) Staphylococcus cohnii strain, were analyzed. Eighteen different SCCmec types were observed, with 28 identified as type IV (29%), 25 as type V (26%), and 1 as type III (1%). Fifteen strains (44%) were untypeable for their SCCmec. Thirty-four percent of MR-CoNS strains contained multiple ccr copies. Type IV and V SCCmec were preferentially associated with S. epidermidis and S. haemolyticus, respectively. MR-CoNS constitute a widespread and highly diversified MR reservoir in the community.

Acute rise in methicillin-resistant Staphylococcus aureus infections in a coastal community.

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Bothwell, Nici Eddy; Shvidler, Joseph; Cable, Benjamin B

2007-12-01

Describe the incidence of head and neck community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections over a 5-year period at a coastal tertiary medical center. Retrospective chart review. All patients presenting to the otolaryngology service with cultures taken from head and neck infections between 1999 and 2004 were eligible for inclusion. Statistical analysis was used to determine significance of the changing incidence of isolated organisms over the study period. CA-MRSA infections rose from 21% to 64% over the 5-year period. The increasing trend in CA-MRSA infections reached statistical significance from 2003 to 2004. All CA-MRSA isolates were resistant to cefazolin and penicillin, but most were sensitive to clindamycin. Our data demonstrates a striking increase in the incidence of CA-MRSA. We have tailored our treatment of cutaneous head and neck infections to include empiric treatment for CA-MRSA using clindamycin. Awareness and monitoring of this trend will be important for all practitioners involved in the care of these patients.

Role of Berberine in the Treatment of Methicillin-Resistant Staphylococcus aureus Infections

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Chu, Ming; Zhang, Ming-Bo; Liu, Yan-Chen; Kang, Jia-Rui; Chu, Zheng-Yun; Yin, Kai-Lin; Ding, Ling-Yu; Ding, Ran; Xiao, Rong-Xin; Yin, Yi-Nan; Liu, Xiao-Yan; Wang, Yue-Dan

2016-04-01

Berberine is an isoquinoline alkaloid widely used in the treatment of microbial infections. Recent studies have shown that berberine can enhance the inhibitory efficacy of antibiotics against clinical multi-drug resistant isolates of methicillin-resistant Staphylococcus aureus (MRSA). However, the underlying mechanisms are poorly understood. Here, we demonstrated that sub-minimum inhibitory concentrations (MICs) of berberine exhibited no bactericidal activity against MRSA, but affected MRSA biofilm development in a dose dependent manner within the concentration ranging from 1 to 64 μg/mL. Further study indicated that berberine inhibited MRSA amyloid fibrils formation, which consist of phenol-soluble modulins (PSMs). Molecular dynamics simulation revealed that berberine could bind with the phenyl ring of Phe19 in PSMα2 through hydrophobic interaction. Collectively, berberine can inhibit MRSA biofilm formation via affecting PSMs’ aggregation into amyloid fibrils, and thereby enhance bactericidal activity of antibiotics. These findings will provide new insights into the multiple pharmacological properties of berberine in the treatment of microbial-generated amyloid involved diseases.

Clinical and epidemiological factors associated with methicillin resistance in community-onset invasive Staphylococcus aureus infections: prospective multicenter cross-sectional study in Korea.

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Eu Suk Kim

Full Text Available Successful empirical therapy of Staphylococcus aureus infections requires the ability to predict methicillin resistance. Our aim was to identify predictors of methicillin resistance in community-onset (CO invasive S. aureus infections. Sixteen hospitals across Korea participated in this study from May to December 2012. We prospectively included cases of S. aureus infection in which S. aureus was isolated from sterile clinical specimens ≤ 72 hours after hospitalization. Clinical and epidemiological data were gathered and compared in methicillin-resistant S. aureus (MRSA and methicillin-susceptible S. aureus (MSSA cases. Community-associated (CA infections were defined as in previous studies. In total, there were 786 cases of community-onset S. aureus infection, 102 (13.0% of which were CA-MRSA. In addition to known risk factors, exposure to 3rd generation cephalosporins in the past 6 months [odds ratio (OR, 1.922; 95% confidence interval (CI, 1.176-3.142] and close contact with chronically ill patients in the past month (OR, 2.647; 95% CI, 1.189-5.891 were independent risk factors for MRSA infection. However, no clinical predictors of CA-MRSA were identified. Methicillin resistance, CO infection, and appropriateness of empirical antibiotics were not significantly related to 30-day mortality. MRSA infection should be suspected in patients recently exposed to 3rd generation cephalosporins or chronically-ill patients. There were no reliable predictors of CA-MRSA infection, and mortality was not affected by methicillin resistance.

Livestock Origin for a Human Pandemic Clone of Community-Associated Methicillin-Resistant Staphylococcus aureus

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Spoor, Laura E.; McAdam, Paul R.; Weinert, Lucy A.

2013-01-01

ABSTRACT The importance of livestock as a source of bacterial pathogens with the potential for epidemic spread in human populations is unclear. In recent years, there has been a global increase in community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections of healthy...... with the independent acquisition of mobile genetic elements encoding antimicrobial resistance and human-specific mediators of immune evasion, consistent with an important role for these genetic events in the capacity to survive and transmit among human populations. In conclusion, we provide evidence that livestock...... at the human-livestock interface. IMPORTANCE Animals are the major source of new pathogens affecting humans. However, the potential for pathogenic bacteria that originally were found in animals to switch hosts and become widely established in human populations is not clear. Here, we report the discovery...

Staphyloxanthin photobleaching sensitizes methicillin-resistant Staphylococcus aureus to reactive oxygen species attack

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Dong, Pu-Ting; Mohammad, Haroon; Hui, Jie; Wang, Xiaoyu; Li, Junjie; Liang, Lijia; Seleem, Mohamed N.; Cheng, Ji-Xin

2018-02-01

Given that the dearth of new antibiotic development loads an existential burden on successful infectious disease therapy, health organizations are calling for alternative approaches to combat methicillin-resistant Staphylococcus aureus (MRSA) infections. Here, we report a drug-free photonic approach to eliminate MRSA through photobleaching of staphyloxanthin, an indispensable membrane-bound antioxidant of S. aureus. The photobleaching process, uncovered through a transient absorption imaging study and quantitated by absorption spectroscopy and mass spectrometry, decomposes staphyloxanthin, and sensitizes MRSA to reactive oxygen species attack. Consequently, staphyloxanthin bleaching by low-level blue light eradicates MRSA synergistically with external or internal reactive oxygen species. The effectiveness of this synergistic therapy is validated in MRSA culture, MRSAinfected macrophage cells. Collectively, these findings highlight broad applications of staphyloxanthin photobleaching for treatment of MRSA infections.

Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA isolates of swine origin form robust biofilms.

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Tracy L Nicholson

Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA colonization of livestock animals is common and prevalence rates for pigs have been reported to be as high as 49%. Mechanisms contributing to the persistent carriage and high prevalence rates of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA strains in swine herds and production facilities have not been investigated. One explanation for the high prevalence of MRSA in swine herds is the ability of these organisms to exist as biofilms. In this report, the ability of swine LA-MRSA strains, including ST398, ST9, and ST5, to form biofilms was quantified and compared to several swine and human isolates. The contribution of known biofilm matrix components, polysaccharides, proteins and extracellular DNA (eDNA, was tested in all strains as well. All MRSA swine isolates formed robust biofilms similar to human clinical isolates. The addition of Dispersin B had no inhibitory effect on swine MRSA isolates when added at the initiation of biofilm growth or after pre-established mature biofilms formed. In contrast, the addition of proteinase K inhibited biofilm formation in all strains when added at the initiation of biofilm growth and was able to disperse pre-established mature biofilms. Of the LA-MRSA strains tested, we found ST398 strains to be the most sensitive to both inhibition of biofilm formation and dispersal of pre-formed biofilms by DNaseI. Collectively, these findings provide a critical first step in designing strategies to control or eliminate MRSA in swine herds.

The increasing importance of community-acquired methicillin-resistant Staphylococcus aureus infections.

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Agostino, Jason W; Ferguson, John K; Eastwood, Keith; Kirk, Martyn D

2017-11-06

To identify groups at risk of methicillin-resistant Staphylococcus aureus (MRSA) infection, patterns of antimicrobial resistance, and the proportion of patients with MRSA infections but no history of recent hospitalisation. Case series of 39 231 patients with S. aureus isolates from specimens processed by the Hunter New England Local Health District (HNELHD) public pathology provider during 2008-2014. Proportion of MRSA infections among people with S. aureus isolates; antimicrobial susceptibility of MRSA isolates; origin of MRSA infections (community- or health care-associated); demographic factors associated with community-associated MRSA infections. There were 71 736 S. aureus-positive specimens during the study period and MRSA was isolated from 19.3% of first positive specimens. Most patients (56.9%) from whom MRSA was isolated had not been admitted to a public hospital in the past year. Multiple regression identified that patients with community-associated MRSA were more likely to be younger (under 40), Indigenous Australians (odds ratio [OR], 2.6; 95% CI, 2.3-2.8), or a resident of an aged care facility (OR, 4.7; 95% CI, 3.8-5.8). The proportion of MRSA isolates that included the dominant multi-resistant strain (AUS-2/3-like) declined from 29.6% to 3.4% during the study period (P resistant strain decreased, new strategies for controlling infections in the community are needed to reduce the prevalence of non-multi-resistant strains.

Daptomycin as a possible new treatment option for surgical management of Methicillin-Resistant Staphylococcus aureus sternal wound infection after cardiac surgery

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Emmert Alexander

2010-08-01

Full Text Available Abstract We present a case of a 77-year old female who had undergone a coronary artery bypass grafting with an aortic valve replacement and developed three month later a Methicillin-Resistant Staphylococcus aureus (MRSA sternal wound infection which was successful treated with Daptomycin combined with vacuum-assisted closure (VAC.

Direct detection of methicillin-resistant Staphylococcus aureus from blood cultures using an immunochromatographic immunoassay-based MRSA rapid kit for the detection of penicillin-binding protein 2a.

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Shin, Kyeong Seob; Song, Hyung Geun; Kim, Haejung; Yoon, Sangsun; Hong, Seung Bok; Koo, Sun Hoe; Kim, Jimyung; Kim, Jongwan; Roh, Kyoung Ho

2010-07-01

Using an EZ-Step MRSA rapid kit, a novel screening test for methicillin-resistant Staphylococcus aureus (MRSA) that detects penicillin-binding protein 2a, 34 of 36 MRSA-positive clinical blood culture samples were positive on direct testing (sensitivity, 94.4%), whereas 21 of 21 methicillin-susceptible S. aureus-positive samples were negative (specificity, 100%).

Simplified screening in an emergency department detected methicillin-resistant Staphylococcus aureus

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Mogensen, Christian Backer; Kjældgaard, Poul; Jensen, Charlotte

2016-01-01

with a non-Danish family within the past three years" and "daily contact with children at a nursery or kindergarten". A new model with only five questions increased the sensitivity insignificantly from 18-55% to 73% in the revised model, whereas no changes were seen for specificity, predictive values....... Furthermore, we assessed if other questions were more adequate and if a simplified screening model would perform equal to or better than the one presently used. METHODS: Swabs were obtained for MRSA culture from patients who were more than ten years old and who had been admitted to an emergency department (ED......INTRODUCTION: All patients admitted to Danish hospitals are screened for methicillin-resistant Staphylococcus aureus (MRSA) by a questionnaire consisting of 19 questions issued by the Danish Health and Medicines Authority (DHMA). This study aimed to evaluate which of the questions were most useful...

Infectious caused by community-acquired Methicillin-Resistant Staphylococcus aureus (CA-MRSA: three-years experience of an universitary hospital in Rome

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Anna Altieri

2010-06-01

Full Text Available To date methicillin-resistant Staphylococcus aureus (MRSA is one of the most common pathogens causing nosocomial infections(1. In Europe the proportion of MRSA is increasing sharply and the distribution varies from country to country. In recent years there has, in various parts of the world, the emergence of infection with strains of S. aureus methicillin-resistant community-acquired (CA-MRSA than those circulating in hospitals(2. These strains contain a gene that confers resistance to methicillin (mec A SSC mec IV which is usually associated with the gene for Leukocidin Panton Valentine (PVL toxin responsible for necrosis of skin and soft tissue (3. In 2006-2008, at the Laboratory of Bacteriology PolyclinicTor Vergata,were isolated a total of 738 strains of S. aureus from biological samples of different nature (oral, vaginal secretions, wound swab, secreted headset, etc ... of patients related to our surgeries.The identification and study of drug sensitivity of strains were performed with the automatic VITEK2 (bioMérieux. Of the 738 strains of S. aureus identified 212 (28.7% were resistant to methicillin (MRSA, with an increasing trend over the years: 46 isolates, respectively, in 2006, 76 in 2007 and 90 in 2008. The highest frequency of MRSA (varying between 85% and 95% was detected in wound swabs from the dispensary and diabetes (diabetic foot.

Resistance to antimicrobials and biofilm formation in Staphylococcus spp. isolated from bovine mastitis in the Northeast of Brazil.

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da Costa Krewer, Carina; Santos Amanso, Evandro; Veneroni Gouveia, Gisele; de Lima Souza, Renata; da Costa, Mateus Matiuzzi; Aparecido Mota, Rinaldo

2015-03-01

Mastitis is the principal disease affecting dairy herds worldwide. The aim of the present study was to characterize phenotypic and genotypic features associated with resistance to antimicrobials in Staphylococcus spp. isolated from 2064 milk samples of 525 lactating cows in the Northeast of Brazil. Of the 218 isolates analyzed, 57.8% were characterized as Staphylococcus aureus, 28% as coagulase-positive staphylococci other than S. aureus (oCPS), and 14.2% as coagulase-negative staphylococci (CNS). The test for susceptibility to antimicrobials showed amoxicillin (32.6%) to be the less effective drug in vitro, and the multi-drug resistance (MDR) rate for beta-lactams varied from 0 to 0.75. The genotypic characterization showed that 93.1% of the samples were tested positive for the blaZ gene, while none amplified mecA. The antibiotic efflux mechanism was observed in 0.9% of isolates. The biofilm formation was found in 3.7 and 96.3% of samples, respectively, on Congo red agar and on the microplate adhesion test, while the icaD gene was present in 92.2% of Staphylococcus spp. The high frequency of blaZ gene observed in this study was associated with the resistance of most Staphylococcus spp. to one or more of the beta-lactams tested, which are routinely used in Brazilian herds for mastitis treatment. The biofilm formation was also detected in the isolates analyzed being an important characteristic for pathogenicity and antimicrobial resistance of bacteria.

Prevalence and genotypic relatedness of methicillin resistant Staphylococcus aureus in a tertiary care hospital

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B A Fomda

2014-01-01

Full Text Available Background: Methicillin-resistant Staphylococcus aureus (MRSA is the most common multidrug-resistant pathogen causing nosocomial infections across the world. MRSA is not only associated with significant mortality and morbidity but also places a large economic strain on our health care system. MRSA isolates are also typically resistant to multiple, non-β-lactam antibiotics. We conducted a prospective study in a tertiary care hospital, to determine the prevalence of MRSA and to establish the clonal distribution of MRSA isolates recovered from various clinical specimens. Materials and Methods: Clinical samples were cultured and S. aureus was identified as per standard microbiological procedures. Susceptibility testing was done by agar disk diffusion and minimum inhibitory concentration (MIC method as recommended by CLSI. Methicillin resistance was detected by phenotypic methods namely, oxacillin disc diffusion (ODD, minimum inhibitory concentration (MIC of oxacillin, cefoxitin disk diffusion (CDD, and MIC of cefoxitin. Amplification of mecA gene by PCR was used as gold standard for detection of methicillin resistance. Pulsed field gel electrophoresis (PFGE typing was performed for MRSA isolates. Results: Out of 390 S. aureus isolates, 154 (39.48% isolates were MRSA and 236 (60.51% isolates were MSSA. Penicillin was the least effective antibacterial drug against the hospital associated S. aureus isolates with 85.64% resistance rate. All the isolates were susceptible to vancomycin. The MRSA showed a high level of resistance to all antimicrobials in general in comparison to the MSSA and the difference was statistically significant (P < 0.05. Multiplex PCR performed for all strains showed amplification of both the mecA and nucA genes in MRSA strains whereas MSSA strains showed amplification of only nucA gene. PFGE of these isolates showed 10 different patterns. Conclusion: Prevalence of MRSA in our hospital was 39.48%. Most of these isolates were

Surgimiento y diseminación de Staphylococcus aureus meticilinorresistente Staphylococcus aureus methicillin-resistant: emergence and dissemination

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Maria Elena Velázquez-Meza

2005-10-01

Full Text Available Las infecciones nosocomiales ocasionadas por cepas de Staphylococcus aureus meticilinorresistentes (SAMR son un problema de salud importante en todo el mundo. Este microorganismo produce una gran variedad de infecciones incluyendo osteomielitis, endocarditis invasora, artritis séptica y septicemia. La multirresistencia es un factor que influye en la persistencia de los SAMR dentro del ámbito hospitalario. La introducción de técnicas de tipificación molecular dentro de las investigaciones epidemiológicas ha provisto nuevas herramientas para conocer el origen y las vías de diseminación de este microorganismo. Una de las conclusiones importantes que han surgido de este tipo de estudios es que un número pequeño de clonas son las responsables de las infecciones estafilocócicas en todo el mundo.Nosocomial infections due to methicillin-resistant Staphylococcus aureus (MRSA is an important health problem worldwide. This microorganism causes a variety of clinical infections, including osteomyelitis, invasive endocarditis, septic arthritis and septicemia. Antimicrobial resistance is a factor that influences the persistence of MRSA in the hospital environment. The introduction of molecular typing techniques in epidemiological investigations has provided new tools for identifying the microorganism's origin and routes of dissemination. One of the most important conclusions that have resulted from these types of studies is that a small number of clones are responsible for most of the staphylococcal infections throughout the world.

Label-free, electrochemical detection of methicillin-resistant staphylococcus aureus DNA with reduced graphene oxide-modified electrodes

KAUST Repository

Wang, Zhijuan

2011-05-01

Reduced graphene oxide (rGO)-modified glassy carbon electrode is used to detect the methicillin-resistant Staphylococcus aureus (MRSA) DNA by using electrochemical impedance spectroscopy. Our experiments confirm that ssDNA, before and after hybridization with target DNA, are successfully anchored on the rGO surface. After the probe DNA, pre-adsorbed on rGO electrode, hybridizes with target DNA, the measured impedance increases dramatically. It provides a new method to detect DNA with high sensitivity (10-13M, i.e., 100 fM) and selectivity. © 2011 Elsevier B.V.

Carriage of methicillin-resistant Staphylococcus aureus by wild urban Norway rats (Rattus norvegicus.

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Chelsea G Himsworth

Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA is an important cause of multi-drug-resistant infections in people, particularly indigent populations. MRSA can be transmitted between people and domestic animals, but the potential for transmission between people and commensal pests, particularly rodents, had not been investigated. The objective of this study was to identify the presence and characterize the ecology of MRSA in rats (Rattus spp. from in an impoverished, inner-city neighborhood. Oropharyngeal swabs were collected from rats trapped in 33 city blocks and one location within the adjacent port. Bacterial culture was performed and MRSA isolates were characterized using a variety of methods, including whole-genome sequencing (WGS. The ecology of MRSA in rats was described using phylogenetic analysis, geospatial analysis, and generalized linear mixed models. MRSA was identified 22 of 637 (3.5% rats tested, although prevalence varied from 0 - 50% among blocks. Isolates belonged to 4 clusters according to WGS, with the largest cluster (n = 10 containing isolates that were genetically indistinguishable from community-acquired USA300 MRSA strains isolated from people within the study area. MRSA strains demonstrated both geographic clustering and dispersion. The odds of an individual rat carrying MRSA increased with increased body fat (OR = 2.53, 95% CI = 1.33-4.82, and in the winter (OR = 5.29, 95% CI = 1.04-26.85 and spring (OR = 5.50, 95% CI = 1.10-27.58 compared to the fall. The results show that urban rats carried the same MRSA lineages occurring in local human and/or animal populations, supporting recent transmission from external sources. MRSA carriage was influenced by season, most likely as a result of temporal variation in rat behavior and rat-human interactions.

Surveillance of Physician-Diagnosed Skin and Soft Tissue Infections Consistent With Methicillin-Resistant "Staphylococcus aureus" (MRSA) among Nebraska High School Athletes, 2008-2012

Science.gov (United States)

Buss, Bryan F.; Connolly, Susan

2014-01-01

Though historically confined to hospital settings, methicillin-resistant Staphylococcus aureus (MRSA) has received increasing attention in the wider community, particularly among athletes. A 2007-2008 investigation in Nebraska concluded that MRSA skin infections were an emerging problem among the state's student athletes. Statewide surveillance…

Population structure analyses of Staphylococcus aureus at Tygerberg Hospital, South Africa, reveals a diverse population, a high prevalence of Panton-Valentine leukocidin genes, and unique local methicillin-resistant S. aureus clones

NARCIS (Netherlands)

Oosthuysen, W. F.; Orth, H.; Lombard, C. J.; Sinha, B.; Wasserman, E.

Studies reporting on the population structure of Staphylococcus aureus in South Africa have focused only on methicillin-resistant S. aureus (MRSA). This study describes the population structure of S. aureus, including methicillin-susceptible S. aureus (MSSA) isolated from patients at Tygerberg

Antimicrobial susceptibility profiles of Staphylococcus spp. from domestic and wild animals

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Isabela de Godoy

Full Text Available ABSTRACT: The aim of this study was to determine the prevalence and diversity of veterinary clinical isolates of Staphylococcus and analyze their antimicrobial susceptibility. One hundred Staphylococcus spp. clinical isolates from domestic and wild animals were subjected to partial sequencing of the 16S rRNA gene to species determination. Antimicrobial susceptibility was obtained by a disk diffusion test against six antibiotics: amoxicillin (AMX, cephalexin (LEX, ciprofloxacin (CIP, erythromycin (ERY, gentamicin (GEN and trimethoprim-sulfamethoxazole (SXT. The most common specie was S. pseudintermedius (61%, 61/100 and resistance to ERY (57%, 57/100, SXT (50%, 50/100 and AMX (46%, 46/100 was detected most frequently. In total, 40% (40/100 of Staphylococcus spp. exhibited a multidrug-resistant (MDR phenotype. Results of this study emphasize that animals are reservoir of MDR Staphylococcus spp.

Efficacy of an alcohol/chlorhexidine hand hygiene program in a hospital with high rates of nosocomial methicillin-resistant Staphylococcus aureus (MRSA) infection.

Science.gov (United States)

Johnson, Paul D R; Martin, Rhea; Burrell, Laurelle J; Grabsch, Elizabeth A; Kirsa, Susan W; O'Keeffe, Jason; Mayall, Barrie C; Edmonds, Deidre; Barr, Wendy; Bolger, Christopher; Naidoo, Humsha; Grayson, M Lindsay

2005-11-21

To assess the effect of a multifaceted hand hygiene culture-change program on health care worker behaviour, and to reduce the burden of nosocomial methicillin-resistant Staphylococcus aureus (MRSA) infections. Timetabled introduction of interventions (alcohol/chlorhexidine hand hygiene solution [ACHRS], improved cleaning of shared ward equipment, targeted patient decolonisation, comprehensive "culture change" package) to five clinical areas of a large university teaching hospital that had high levels of MRSA. Health care worker hand hygiene compliance; volume of ACHRS used; prevalence of patient and health care worker MRSA colonisation; environmental MRSA contamination; rates of clinical MRSA infection; and rates of laboratory detection of ESBL-producing Escherichia coli and Klebsiella spp. In study wards, health care worker hand hygiene compliance improved from a pre-intervention mean of 21% (95% CI, 20.3%-22.9%) to 42% (95% CI, 40.2%-43.8%) 12 months post-intervention (P hand hygiene compliance and reducing nosocomial MRSA infections, despite high-level MRSA endemicity.

Prevalence and molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) among pigs on German farms and import of livestock-related MRSA into hospitals

NARCIS (Netherlands)

Köck, R; Harlizius, J; Bressan, N; Laerberg, R; Wieler, L H; Witte, W; Deurenberg, R H; Voss, A; Becker, K; Friedrich, A W

The aim of this study was to evaluate the prevalence and molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) among pigs and estimate the impact of this animal reservoir on human healthcare. Nasal swabs were derived from 1,600 pigs at 40 German farms. The MRSA were

Prevalence and molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) among pigs on German farms and import of livestock-related MRSA into hospitals.

NARCIS (Netherlands)

Kock, R.; Harlizius, J.; Bressan, N.; Laerberg, R.; Wieler, L.H.; Witte, W.; Deurenberg, R.H.; Voss, A.; Becker, K.; Friedrich, A.W.

2009-01-01

The aim of this study was to evaluate the prevalence and molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) among pigs and estimate the impact of this animal reservoir on human healthcare. Nasal swabs were derived from 1,600 pigs at 40 German farms. The MRSA were

Molecular epidemiology of community-onset methicillin-resistant Staphylococcus aureus infections in Israel.

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Biber, A; Parizade, M; Taran, D; Jaber, H; Berla, E; Rubin, C; Rahav, G; Glikman, D; Regev-Yochay, G

2015-08-01

Data on community-associated (CA) methicillin-resistant Staphylococcus aureus (MRSA) in Israel are scarce. The objective of this study was to characterize the major CA-MRSA clones in Israel. All clinical MRSA isolates detected in the community during a period of 2.5 years (2011-2013) from individuals insured by a major health maintenance organization in Israel were collected, with additional data from medical records. Antibiotic susceptibility patterns and staphylococcal chromosomal cassette mec (SCCmec) typing were determined. SCCmec IV and V isolates were further typed by pulsed-field gel electrophoresis (PFGE), spa typing, and detection of a panel of toxin genes. MRSA were detected in 280 patients, mostly from skin infections. Patients with SCCmec IV (n = 120, 43 %) were younger (p Israel, approximately 20 % are typical CA-MRSA clones, mainly USA300 and a local clone, t991.

The detection and differentiation of methicillin-resistant and methicillin-susceptible Staphylococcus aureus endocarditis by using the BD GeneOhm StaphSR Assay.

Science.gov (United States)

Frey, Amy B; Wilson, Deborah A; LaSalvia, Margaret M; Tan, Carmela D; Rodriguez, E Rene; Shrestha, Nabin K; Hall, Gerri S; Procop, Gary W

2011-11-01

We use the BD GeneOhm StaphSR Assay (BD Diagnostics, Oakville, Canada) to screen for Staphylococcus aureus nasal colonization and sought to evaluate this assay for the assessment of valve specimens from patients with endocarditis. We examined 23 paired fresh and formalin-fixed, paraffin-embedded cardiac valve tissue samples, 12 of which had S aureus endocarditis, using the BD GeneOhm StaphSR Assay for the detection and differentiation of methicillin-susceptible and methicillin-resistant S aureus. This assay appropriately characterized all specimens with respect to the presence or absence of S aureus. There was an 87.5% correlation between the presence or absence of the mecA gene and the oxacillin susceptibility results for the S aureus isolates studied. The GeneOhm StaphSR assay accurately detected S aureus in cardiac valve tissue samples. Rare discordances were observed between oxacillin susceptibility status and mecA gene detection by this assay.

Stethoscopes as a source of hospital-acquired methicillin-resistant Staphylococcus aureus.

Science.gov (United States)

Russell, Abigail; Secrest, Janet; Schreeder, Carolyn

2012-04-01

Stethoscopes are potential vectors of methicillin-resistant Staphylococcus aureus (MRSA). The purpose of this project was to determine the presence of MRSA on the diaphragms of personal and unit stethoscopes within a hospital setting before and after cleaning with alcohol prep pads. The sample consisted of 141 personal and unit stethoscopes in adult medical-surgical and intensive care units of a large university hospital in the Southeast. Each stethoscope was cultured once before cleaning and once after cleaning. Cultures were obtained using sterile swabs and inoculated on a selective medium for MRSA. Bacterial growth was noted in the precleaning group, but no MRSA colonies were detected. The postcleaning group had no bacterial growth. There was not enough data to statistically support that isopropyl alcohol is effective in decreasing bacterial counts; however, these findings suggest that current disinfection guidelines are effective in preventing MRSA colonization on stethoscopes in this setting. Copyright © 2012 American Society of PeriAnesthesia Nurses. Published by Elsevier Inc. All rights reserved.

Frequency, antimicrobial susceptibility and clonal distribution of methicillin-resistant Staphylococcus pseudintermedius in canine clinical samples submitted to a veterinary diagnostic laboratory in Italy: A 3-year retrospective investigation

DEFF Research Database (Denmark)

Ventrella, G.; Moodley, A.; Grandolfo, E.

2017-01-01

In the last decade there has been a rapid global spread of methicillin-resistant Staphylococcus pseudintermedius (MRSP) clones displaying multidrug resistance in dogs. We investigated prevalence, antimicrobial susceptibility and clonal distribution of MRSP isolated from clinical canine samples be...

Biotechnological Methods for Precise Diagnosis of Methicillin Resistance in Staphylococci

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Aija Zilevica

2005-04-01

Full Text Available Antimicrobial resistance is one of the most urgent problems in medicine nowadays. The purpose of the study was to investigate the microorganisms resistant to first-line antimicrobials, including gram-positive cocci, particularly the methicillin-resistant Staphylococcus aureus and coagulase-negative Staphylococci, the major agents of nosocomial infections. Owing to the multi-resistance of these agents, precise diagnosis of the methicillin resistance of Staphylococci is of greatest clinical importance. It is not enough to use only conventional microbiological diagnostic methods. Biotechnological methods should be also involved. In our studies, the following methicillin resistance identification methods were used: the disk diffusion method, detection of the mecA gene by PCR, E-test and Slidex MRSA test. For molecular typing, PFGL, RAPD tests and detection of the coa gene were used. All the MRS strains were multiresistant to antibacterials. No vancomycine resistance was registered.

Evaluation of antibacterial and antibiofilm mechanisms by usnic acid against methicillin-resistant Staphylococcus aureus.

Science.gov (United States)

Pompilio, Arianna; Riviello, Antonella; Crocetta, Valentina; Di Giuseppe, Fabrizio; Pomponio, Stefano; Sulpizio, Marilisa; Di Ilio, Carmine; Angelucci, Stefania; Barone, Luana; Di Giulio, Andrea; Di Bonaventura, Giovanni

2016-10-01

To evaluate the antibacterial and antibiofilm mechanisms of usnic acid (USN) against methicillin-resistant Staphylococcus aureus from cystic fibrosis patients. The effects exerted by USN at subinhibitory concentrations on S. aureus Sa3 strain was evaluated by proteomic, real-time PCR and electron microscopy analyses. Proteomic analysis showed that USN caused damage in peptidoglycan synthesis, as confirmed by microscopy. Real-time PCR analysis showed that antibiofilm activity of USN is mainly due to impaired adhesion to the host matrix binding proteins, and decreasing lipase and thermonuclease expression. Our data show that USN exerts anti-staphylococcal effects through multitarget inhibitory effects, thus confirming the rationale for considering it 'lead compound' for the treatment of cystic fibrosis infections.

Carcinogenic Activities and Sperm Abnormalities of Methicillin Resistance Staphylococcus aureus and Inhibition of Their Virulence Potentials by Ayamycin.

Science.gov (United States)

El-Gendy, Mervat Morsy Abbas Ahmed; Abdel-Wahhab, Khaled G; Mannaa, Fathia A; Farghaly, Ayman A; El-Bondkly, Ahmed M A

2017-11-01

This investigation aimed to study the in vivo harmful effects of the subcutaneous injection of different methicillin resistance Staphylococcus aureus extracts (MRSA2, MRSA4, MRSA10, MRSA69, MRSA70, MRSA76, and MRSA78). Such strains represented the highest minimum inhibition concentration toward methicillin with various multidrug-resistant patterns. The obtained results revealed that rats injected with the MRSA4 extract died immediately after the last dose indicating the high cytotoxicity of MRSA4 strain (100% mortality). While the mortalities in other groups injected by the other MRSA extracts ranged from 50 to 75%. In comparison with the normal animal group, all MRSA extracts induced a hepatotoxic effect which was indicated from the significant (p study focused on fighting MRSA virulence factors by the new compound ayamycin, which proved to be potent anti-virulence factor against all MRSA strains under study by significant decreasing of their streptokinase activities, hemolysin synthesis, biofilm formation, and their cell surface hydrophobicity.

Synergism between Medihoney and rifampicin against methicillin-resistant Staphylococcus aureus (MRSA.

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Patrick Müller

Full Text Available Skin and chronic wound infections caused by highly antibiotic resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA are an increasing and urgent health problem worldwide, particularly with sharp increases in obesity and diabetes. New Zealand manuka honey has potent broad-spectrum antimicrobial activity, has been shown to inhibit the growth of MRSA strains, and bacteria resistant to this honey have not been obtainable in the laboratory. Combinational treatment of chronic wounds with manuka honey and common antibiotics may offer a wide range of advantages including synergistic enhancement of the antibacterial activity, reduction of the effective dose of the antibiotic, and reduction of the risk of antibiotic resistance. The aim of this study was to investigate the effect of Medihoney in combination with the widely used antibiotic rifampicin on S. aureus. Using checkerboard microdilution assays, time-kill curve experiments and agar diffusion assays, we show a synergism between Medihoney and rifampicin against MRSA and clinical isolates of S. aureus. Furthermore, the Medihoney/rifampicin combination stopped the appearance of rifampicin-resistant S. aureus in vitro. Methylglyoxal (MGO, believed to be the major antibacterial compound in manuka honey, did not act synergistically with rifampicin and is therefore not the sole factor responsible for the synergistic effect of manuka honey with rifampicin. Our findings support the idea that a combination of honey and antibiotics may be an effective new antimicrobial therapy for chronic wound infections.

Impairments of mecA gene detection in bovine Staphylococcus spp.

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Dayanne Araújo de Melo

2014-09-01

Full Text Available Staphylococcus aureus antimicrobial resistance, especially to beta-lactams, favors treatment failures and its persistence in herd environment. This work aimed to develop a more specific primer for mecA gene detection based on the comparison of the conserved regions from distinct host origins and also investigated the presence of homologue mecA LGA251 in bovine strains. A total of 43 Staphylococcus spp. were included in this study, comprising 38 bovine S. aureus, two human and three equine coagulase-negative staphylococci (CNS. Phenotypical methicillin-resistance detection was performed through oxacillin agar-screening and cefoxitin disk-diffusion test. None isolate tested positive for mecA LGA251 gene. For mecA gene PCR, new primers were designed based on the sequences of human S. aureus (HE681097 and bovine S. sciuri (AY820253 mecA. The new primers based on the S. aureus mecA sequence amplified fragments of human and equine CNS and the ones based on S. sciuri mecA sequence only yielded fragments for S. aureus bovine strains. Multiples alignments of mecA gene sequences from bovine, human and equine revealed punctual but significant differences in bovine strains that can lead to the mecA gene detection impairment. The observed divergences of mecA gene sequences are not a matter of animal or human origin, it is a specificity of bovine samples.

Livestock-Associated Methicillin Resistant and Methicillin Susceptible Staphylococcus aureus Sequence Type (CC)1 in European Farmed Animals: High Genetic Relatedness of Isolates from Italian Cattle Herds and Humans

DEFF Research Database (Denmark)

Alba, Patricia; Feltrin, Fabiola; Cordaro, Gessica

2015-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) Sequence Type (ST)1, Clonal Complex( CC) 1, SCCmec V is one of the major Livestock-Associated (LA-) lineages in pig farming industry in Italy and is associated with pigs in other European countries. Recently, it has been increasingly detected...... in Italian dairy cattle herds. The aim of this study was to analyse the differences between ST1 MRSA and methicillin-susceptible S. aureus (MSSA) from cattle and pig herds in Italy and Europe and human isolates. Sixty-tree animal isolates from different holdings and 20 human isolates were characterized...... by pulsed-field gel electrophoresis (PFGE), spa-typing, SCCmec typing, and by micro-array analysis for several virulence, antimicrobial resistance, and strain/host-specific marker genes. Three major PFGE clusters were detected. The bovine isolates shared a high (>= 90% to 100%) similarity with human...

Presentación atípica de piomiositis tropical difusa de psoas por Staphylococcus aureus meticilino resistente Atypical presentation of diffuse tropical pyomiositis of the psoas due to methicillin resistant Staphylococcus aureus

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Ray Ticse

2012-03-01

Full Text Available La piomiositis tropical difusa primaria es una enfermedad de presentación infrecuente en nuestro medio, con pocos casos asociados a Staphylococcus aureus meticilino resistente, adquirido en la comunidad (MRSA-AC. Se presenta el caso de un paciente de 70 años, con tratamiento irregular para diabetes mellitus tipo 2, que fue hospitalizado por presentar un cuadro de diez días de evolución, con dolor lumbar irradiado a miembro inferior izquierdo, fiebre y flexión forzada de la cadera derecha por dolor a la movilización. El diagnóstico de piomiositis difusa de ambos psoas se realizó con resonancia magnética. Del cultivo de una colección paravertebral posterior se aisló Staphylococcus aureus resistente a oxacilina, penicilina y dicloxacilina.Diffuse tropical primary pyomyositis is an infrequent entity in our country, with few cases associated to communityacquired Methicillin- resistant Staphylococcus aureus. There are no reported cases of Community-Acquired Methicillin- Resistant Staphylococcus aureus (CA- MRSA in Peru. We present the case of a 70 year old male with a previous diagnosis of type 2 diabetes mellitus, receiving irregular treatment, who was admitted to the hospital with a history of 10 days of low back pain radiating to the left leg, fever and forced flexion of the right hip due to pain during movement. The diagnosis of diffuse pyomyositis of both psoas muscles was performed with MRI and culture of a posterior paravertebral collection, from which Staphylococcus aureus resistant to oxacillin, penicillin and dicloxacillin was isolated.

Successful treatment of methicillin-resistant Staphylococcus aureus osteomyelitis with combination therapy using linezolid and rifampicin under therapeutic drug monitoring.

Science.gov (United States)

Ashizawa, Nobuyuki; Tsuji, Yasuhiro; Kawago, Koyomi; Higashi, Yoshitsugu; Tashiro, Masato; Nogami, Makiko; Gejo, Ryuichi; Narukawa, Munetoshi; Kimura, Tomoatsu; Yamamoto, Yoshihiro

2016-05-01

Linezolid is an effective antibiotic against most gram-positive bacteria including drug-resistant strains such as methicillin-resistant Staphylococcus aureus. Although linezolid therapy is known to result in thrombocytopenia, dosage adjustment or therapeutic drug monitoring of linezolid is not generally necessary. In this report, however, we describe the case of a 79-year-old woman with recurrent methicillin-resistant S. aureus osteomyelitis that was successfully treated via surgery and combination therapy using linezolid and rifampicin under therapeutic drug monitoring for maintaining an appropriate serum linezolid concentration. The patient underwent surgery for the removal of the artificial left knee joint and placement of vancomycin-impregnated bone cement beads against methicillin-resistant S. aureus after total left knee implant arthroplasty for osteoarthritis. We also initiated linezolid administration at a conventional dose of 600 mg/h at 12-h intervals, but reduced it to 300 mg/h at 12-h intervals on day 9 because of a decrease in platelet count and an increase in serum linezolid trough concentration. However, when the infection exacerbated, we again increased the linezolid dose to 600 mg/h at 12-h intervals and performed combination therapy with rifampicin, considering their synergistic effects and the control of serum linezolid trough concentration via drug interaction. Methicillin-resistant S. aureus infection improved without reducing the dose of or discontinuing linezolid. The findings in the present case suggest that therapeutic drug monitoring could be useful for ensuring the therapeutic efficacy and safety of combination therapy even in patients with osteomyelitis who require long-term antibiotic administration. Copyright © 2015 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Methicillin-resistente Staphylococcus aureus (MRSA) in der Veterinärmedizin : ein "New Emerging Pathogen"?

NARCIS (Netherlands)

Walther, Birgit; Friedrich, Alexander W; Brunnberg, Leo; Wieler, Lothar H; Lübke-Becker, Antina

2006-01-01

The problem of nosocomial infections is of increasing importance in veterinary medicine. As an example, this review summarizes current knowledge regarding methicillin-resistant Staphylococcus aureus (MRSA) as a typical example, as these pathogens are the most important agents of nosocomial

High prevalence of methicillin-resistant coagulase-negative staphylococci isolated from a university environment in Thailand.

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Seng, Rathanin; Leungtongkam, Udomluk; Thummeepak, Rapee; Chatdumrong, Wassana; Sitthisak, Sutthirat

2017-06-01

The present study was conducted to isolate and characterize the molecular epidemiology of the methicillin-resistant staphylococci in the general university environment, where all five locations; the library, restrooms, canteens, computer rooms and outdoor surfaces, are in common use by a large population of students. We used Mannitol Salt Agar (MSA) supplemented with 4 μg/ml of oxacillin to screen the methicillin-resistant staphylococci. The species level was identified by PCR of rdr (Staphylococcus epidermidis), groESL (Staphylococcus haemolyticus) and nuc (Staphylococcus aureus and Staphylococcus warneri) genes and DNA sequencing of tuf and dnaJ genes. The susceptibility patterns of the isolates were determined using the disk diffusion method. Antibiotic and disinfectant resistance genes, together with SCCmec types, were detected by the PCR method. The methicillin resistant-staphylococci were isolated from 41 of 200 samples (20.5%), and all of them were found to be methicillin-resistant coagulase negative staphylococci (MR-CoNS). The library had the highest percentage of contamination, with 43.3% of the samples found to be contaminated. All isolates belonged to 6 different species including S. haemolyticus, S. epidermidis, S. warneri, S. cohnii, S. saprophyticus and S. hominis. The antimicrobial resistance rates were highest against penicillin (100%), then cefoxitin (73.1%), erythromycin (73.1%) and oxacillin (68.3%). Altogether, the isolates were approximately 61.0% multidrug resistant (MDR), with the S. epidermidis isolates being the most multidrug resistant. The prevalence of the qacA/B gene was detected in 63.4% of the isolates, and SCCmec could be typed in 43.9% (18/41) of the isolates. The type range was: II (n = 1), IVd (n = 1), I (n = 2), V (n = 6), IVa (n = 8) and untypeable (n = 23). This result indicates that these university environments are contaminated with methicillin-resistant coagulase negative staphylococci that carry various SCCmec types and

Inducible Clindamycin Resistance in Staphylococcus Species

International Nuclear Information System (INIS)

Afridi, F. I.; Zeb, M.; Farooqi, B. J.; Murtaza, G.; Hussain, A.

2014-01-01

Objective: To determine the frequency of inducible clindamycin resistance in clinical isolates of Staphylococcus species by phenotypic D-test. Study Design: Observational study. Place and Duration of Study: Ziauddin University Hospital, Karachi, from July to December 2011. Methodology: Consecutive clinical isolates of Staphylococcus species were collected and identified by conventional microbiological techniques. Antimicrobial susceptibility testing and inducible clindamycin resistance was carried out by performing D-test using CLSI criteria. Methicillin resistance was detected by using Cefoxitin disk as a surrogate marker. Statistical analysis was performed by SPSS version-17. Results: A total of 667 clinical isolates of Staphylococcus species were obtained during the study period. In these isolates, 177 (26.5%) were Staphylococcus aureus, and 490 (73.5%) were coagulase negative Staphylococci. The total frequency of inducible clindamycin resistance among isolates of Staphylococcus species was 120/667 (18%). Frequency of inducible clindamycin resistance among coagulase negative Staphylococci group and Staphylococcus aureus group were 18.57% and 16.38% respectively. Median age of patients in D-test positive group was 19.5 (1 - 54) years. Conclusion: The frequency of inducible clindamycin resistance among Staphylococcus species may differ in different hospital setup. Clinical microbiology laboratories should implement testing simple and effective D-test on all Staphylococcus species. D-test positive isolates should be reported clindamycin resistant to decrease treatment failure. (author)

Detection of meca gene from methicillin resistant staphylococcus aureus isolates of north sumatera

Science.gov (United States)

Septiani Nasution, Gabriella; Suryanto, Dwi; Lia Kusumawati, R.

2018-03-01

Methicillin Resistant Staphylococcus aureus (MRSA) is a major pathogen associated with hospital-acquired infections (nosocomial infections). MRSA is a type of S. aureus resistant to the sub-group of beta-lactam antibiotics such as penicillin, cephalosporin, monobactam, and carbapenem. MRSA is resistant because of genetic changes caused by exposure to irrational antibiotic therapy. This study aimed to detect mecA gene in North Sumatra isolates of MRSA and to determine the pattern of antibiotic resistance in S.aureus isolates classified as MRSA by Vitek 2 Compact in the Central Public Hospital Haji Adam Malik, Medan. Samples were 40 isolates of S. aureus classified as MRSA obtained from clinical microbiology specimens. DNA isolation of the isolates was conducted by a method of freeze-thaw cycling. Amplification of mecA gene was done by PCR technique using specific primer for the gene. PCR products were visualized using mini-gel electrophoresis. The results showed that all MRSA isolates showed to have 533 bp band of mecA. Antibiotics test of Vitek 2 Compact showed that despite all isolates were resistant to beta-lactam antibiotics groups; the isolates showed multidrug resistant to other common antibiotics, such as aminoglycosides, macrolides, and fluoroquinolones. However, they were still sensitive to vancomycin (82.5% isolates), linezolid (97.5% isolates), and tigecycline (100% isolates).

Presence of a novel DNA methylation enzyme in methicillin-resistant Staphylococcus aureus isolates associated with pig farming leads to uninterpretable results in standard pulsed-field gel electrophoresis analysis.

NARCIS (Netherlands)

Bens, C.C.; Voss, A.; Klaassen, C.H.W.

2006-01-01

Genomic DNA from methicillin-resistant Staphylococcus aureus isolates recovered from pigs and their caretakers proved resistant to SmaI digestion, leading to uninterpretable results in standard pulsed-field gel electrophoresis. This is the result of a yet unknown restriction/methylation system in

A Livestock-Associated, Multidrug-Resistant, Methicillin-Resistant Staphylococcus aureus Clonal Complex 97 Lineage Spreading in Dairy Cattle and Pigs in Italy

DEFF Research Database (Denmark)

Feltrin, Fabiola; Alba, Patricia; Kraushaar, Britta

2016-01-01

by macrorestriction pulsed-field gel electrophoresis (PFGE) analysis, multilocus sequence typing (MLST), spa typing, staphylococcal cassette chromosome mec (SCCmec) typing, and antimicrobial resistance pattern analysis. Virulence and resistance genes were investigated by PCR and microarray analysis. Most...... resistance, fluoroquinolone resistance (n = 33), tet(K) in 32/37 tet(M)-positive isolates, and blaZ in almost all MRSA isolates. Few host-associated differences were detected among CC97 MRSA isolates: their extensive MDR nature in both pigs and dairy cattle may be a consequence of a spillback from pigs......Pandemic methicillin-resistant Staphylococcus aureus (MRSA) clonal complex 97 (CC97) lineages originated from livestock-to-human host jumps. In recent years, CC97 has become one of the major MRSA lineages detected in Italian farmed animals. The aim of this study was to characterize and analyze...

Prolonged exposure of methicillin-resistant Staphylococcus aureus (MRSA) COL strain to increasing concentrations of oxacillin results in a multidrug-resistant phenotype

DEFF Research Database (Denmark)

Martins, Ana; Couto, Isabel; Aagaard, Lone

2007-01-01

Our previous studies demonstrated that exposure of a bacterium to increasing concentrations of an antibiotic would increase resistance to that antibiotic as a consequence of activating efflux pumps. This study utilises the same approach; however, it employs the methicillin-resistant Staphylococcus...... aureus (MRSA) COL strain, which is highly resistant to oxacillin (OXA). MRSA COL was adapted to 3200 mg/L of OXA. Changes in resistance to other antibiotics were evaluated and efflux pump activity during the adaptation process was determined. MRSA COL was exposed to stepwise two-fold increases of OXA....... At the end of each step, minimum inhibitory concentration determination for erythromycin (ERY) and other antibiotics was conducted. Reserpine (RES) was employed to evaluate whether resistance to ERY was dependent on efflux pump activity. Efflux pump activity was also evaluated using the ethidium bromide (EB...

Electronic hand hygiene monitoring as a tool for reducing health care-associated methicillin-resistant Staphylococcus aureus infection.

Science.gov (United States)

Kelly, J William; Blackhurst, Dawn; McAtee, Wendy; Steed, Connie

2016-08-01

Electronic monitoring of hand hygiene compliance using the World Health Organization's My 5 Moments for Hand Hygiene is a new innovation that has not yet been shown to reduce hospital infections. We analyzed existing data from 23 inpatient units over a 33-month period and found a significant correlation between unit-specific improvements in electronic monitoring compliance and reductions in methicillin-resistant Staphylococcus aureus infection rates (r = -0.37, P < .001). Copyright © 2016 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

The rise of methicillin resistant Staphylococcus aureus: now the dominant cause of skin and soft tissue infection in Central Australia.

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Macmorran, E; Harch, S; Athan, E; Lane, S; Tong, S; Crawford, L; Krishnaswamy, S; Hewagama, S

2017-10-01

This study aimed to examine the epidemiology and treatment outcomes of community-onset purulent staphylococcal skin and soft tissue infections (SSTI) in Central Australia. We performed a prospective observational study of patients hospitalised with community-onset purulent staphylococcal SSTI (n = 160). Indigenous patients accounted for 78% of cases. Patients were predominantly young adults; however, there were high rates of co-morbid disease. Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) was the dominant phenotype, accounting for 60% of cases. Hospitalisation during the preceding 6 months, and haemodialysis dependence were significant predictors of CA-MRSA infection on univariate analysis. Clinical presentation and treatment outcomes were found to be comparable for methicillin-susceptible S. aureus (MSSA) and methicillin-resistant cases. All MRSA isolates were characterised as non-multi-resistant, with this term used interchangeably with CA-MRSA in this analysis. We did not find an association between receipt of an active antimicrobial agent within the first 48 h, and progression of infection; need for further surgical debridement; unplanned General Practitioner or hospital re-presentation; or need for further antibiotics. At least one adverse outcome was experienced by 39% of patients. Clindamycin resistance was common, while rates of trimethoprim-sulfamethoxazole resistance were low. This study suggested the possibility of healthcare-associated transmission of CA-MRSA. This is the first Australian report of CA-MRSA superseding MSSA as the cause of community onset staphylococcal SSTI.

SUSCEPTIBILIDAD ANTIMICROBIANA DE CEPAS DE Staphylococcus spp. AISLADAS DEL PERSONAL DE ENFERMERÍA DE LA UNIDAD DE NEONATOLOGÍA DEL HOSPITAL UNIVERSITARIO “ANTONIO PATRICIO DE ALCALÁ”, CUMANÁ, VENEZUELA | ANTIMICROBIAL SUSCEPTIBILITY OF Staphylococcus spp. STRAINS ISOLATED FROM THE NURSING PERSONNEL OF NEONATOLOGY UNIT IN THE UNIVERSITY HOSPITAL “ANTONIO PATRICIO DE ALCALÁ”, CUMANÁ, VENEZUELA

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Edda Díaz Ruíz

2016-08-01

Full Text Available The aim of this research was to evaluate the antimicrobial susceptibility of Staphylococcus spp. strains isolated in nostrils and hands from 19 nursing professionals, associated to the neonatology unit of the University Hospital “Antonio Patricio de Alcalá”, Cumana, Sucre state, during the period July - August 2009. The bacterial identification was carried out by conventional microbiological methods. To determine the antimicrobial susceptibility, the disk diffusion method was used, according to the Clinical Laboratory and Standards Institute guideline. Results showed that 21.05% of individual samples were of Staphylococcus aureus and 78.95% were coagulase negative Staphylococcus (CNS. Most isolations were obtained from the nostrils (50.00%. Regarding the antimicrobial susceptibility, strains of S. aureus from the nostrils were resistant to Oxacilline 66.67% and 33.33% to Ciprofloxacin and Erythromycin. CNS were resistant to Erythromycin (90.00%, Clindamycin (50.00%, Ciprofloxacin (40.00% and Oxacilline (30.00%. The S. aureus strains isolated from hands resulted resistant to all the studied antibiotics (50.00%, and in the CNS isolated from hands, most resistance was related to Erythromycin (91.67%, while Clindamycin, Oxacilline and Ciprofloxacin showed resistance percentages of 58.33%, 50.00% and 41.67%, respectively. This study reveals the presence of methicillin-resistant strains of Staphylococcus spp. among the nursing personnel of the neonatal unit, and the colonization of these bacteria increases the likelihood of transmission of strains from staff to patient, and among them and the community.

Community-acquired necrotizing pneumonia caused by methicillin-resistant Staphylococcus aureus ST30-SCCmecIVc-spat019-PVL positive in San Antonio de Areco, Argentina.

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Fernandez, Silvina; Murzicato, Sofía; Sandoval, Orlando; Fernández-Canigia, Liliana; Mollerach, Marta

2015-01-01

Community-acquired methicillin-resistant Staphylococcus aureus is the first cause of skin and soft tissue infections, but can also produce severe diseases such as bacteremia, osteomyelitis and necrotizing pneumonia. Some S. aureus lineages have been described in cases of necrotizing pneumonia worldwide, usually in young, previously healthy patients. In this work, we describe a fatal case of necrotizing pneumonia due to community-acquired methicillin-resistant S. aureus clone ST30-SCCmecIVc-spat019-PVL positive in an immunocompetent adult patient. Copyright © 2014 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Methicillin-resistant Staphylococcus aureus and Acinetobacter baumannii on computer interface surfaces of hospital wards and association with clinical isolates

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Ma Ling

2009-10-01

Full Text Available Abstract Background Computer keyboards and mice are potential reservoirs of nosocomial pathogens, but routine disinfection for non-water-proof computer devices is a problem. With better hand hygiene compliance of health-care workers (HCWs, the impact of these potential sources of contamination on clinical infection needs to be clarified. Methods This study was conducted in a 1600-bed medical center of southern Taiwan with 47 wards and 282 computers. With education and monitoring program of hand hygiene for HCWs, the average compliance rate was 74% before our surveillance. We investigated the association of methicillin-resistant Staphylococcus aureus (MRSA, Pseudomonas aeruginosa and Acinetobacter baumannii, three leading hospital-acquired pathogens, from ward computer keyboards, mice and from clinical isolates in non-outbreak period by pulsed field gel electrophoresis and antibiogram. Results Our results revealed a 17.4% (49/282 contamination rate of these computer devices by S. aureus, Acinetobacter spp. or Pseudomonas spp. The contamination rates of MRSA and A. baumannii in the ward computers were 1.1% and 4.3%, respectively. No P. aeruginosa was isolated. All isolates from computers and clinical specimens at the same ward showed different pulsotypes. However, A. baumannii isolates on two ward computers had the same pulsotype. Conclusion With good hand hygiene compliance, we found relatively low contamination rates of MRSA, P. aeruginosa and A. baumannii on ward computer interface, and without further contribution to nosocomial infection. Our results suggested no necessity of routine culture surveillance in non-outbreak situation.

Bovine mastitis outbreak in Japan caused by methicillin-resistant Staphylococcus aureus New York/Japan clone.

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Hata, Eiji

2016-05-01

Many methicillin-resistant Staphylococcus aureus (MRSA) strains are multidrug-resistant; consequently, infectious diseases involving MRSA are recognized as troublesome diseases not only in human health care but also in animal health care. A bovine mastitis case caused by MRSA isolates of the New York/Japan clone (NJC), which occurred in Japan in 2005, was monitored in the current study. Isolates of the NJC are typical of hospital-acquired MRSA in Japan. The genetic backgrounds of these strains differ from those of bovine-associated S. aureus, which are typically of clonal complex (CC)97, CC705, and CC133. Moreover, the NJC isolates in this bovine outbreak possessed a β-hemolysin-converting bacteriophage and an immune evasion cluster, as found in the NJC isolates from humans, so it is possible that this clone was introduced into the dairy herd by a human carrier. Most bovine intramammary infections (IMIs) caused by the NJC isolates in our study were asymptomatic, and obvious clinical signs were recognized in only the first 3 infected cows. Of a total of 78 cows, 31 cows were MRSA carriers, and these carrier cows were detected by testing the milk of all lactating cows at 1-month intervals. These S. aureus carrier cows were culled or the infected quarter was dried off and no longer milked. Both IMI and mastitis caused by MRSA were completely eradicated after 5 months. Genotyping data suggested that exchanging of the staphylococcal cassette chromosome mec (the determining factor in methicillin resistance) occurred easily between MRSA and methicillin-sensitive S. aureus in the udders of carrier cows. This case study demonstrates an effective procedure against the spread of MRSA in a dairy herd, and highlights the risk of emergence of new MRSA strains in a dairy herd. © 2016 The Author(s).

Nasal carriage of mecA-positive methicillin-resistant Staphylococcus aureus in pigs exhibits dose-response to zinc supplementation.

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Amachawadi, Raghavendra G; Scott, Harvey M; Nitikanchana, Sureemas; Vinasco, Javier; Tokach, Mike D; Dritz, Steve S; Nelssen, Jim L; Goodband, Robert D; Nagaraja, Tiruvoor G

2015-02-01

Zinc (Zn) is often supplemented at elevated concentrations in swine diets, particularly in piglets, to prevent enteric infections and promote growth. Previous studies from Denmark have suggested a genetic linkage and a phenotypic association between Zn resistance, encoded by czrC, and methicillin-resistance conferred by mecA in Staphylococcus aureus. Such an association has not been reported in the U.S. swine population. We conducted an analysis of the effects of Zn, supplemented as zinc oxide (ZnO), on the nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) in nursery (n=40) and finisher pigs (n=40) enrolled in a nutritional study. Nasal swabs, collected from nursery and finisher pigs, were inoculated onto MRSA CHROMagar and presumptive MRSA colonies were tested for the presence of mecA and czrC genes by polymerase chain reaction. Zinc susceptibility was determined by the agar dilution method. The prevalence of mecA-positive MRSA was 10% (4/40) and 20% (8/40) among nursery and finisher pigs, respectively. Of the 12 mecA-positive S. aureus isolates, 7 had the czrC gene (58.3%) compared to none among the 68 mecA-negative isolates. The presence of both mecA (p=0.002) and czrC (p=0.006) genes were positively associated with higher levels of Zn supplementation. The median minimum inhibitory concentrations of Zn for czrC-positive and czrC-negative isolates were 12 and 2 mM, respectively (presistance among S. aureus in pigs.

Molecular Typing and Antimicrobial Susceptibility of Methicillin-Resistant Staphylococcus aureus Isolated from Bovine Milk in Tanzania.

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Mohammed, Jibril; Ziwa, Michael Henry; Hounmanou, Yaovi Mahuton Gildas; Kisanga, Adela; Tuntufye, Huruma Nelwike

2018-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) in raw milk can be transmitted from animals to humans, and in Tanzania raw milk is sold in local markets and consumed as purchased. This study was performed to determine the molecular characteristics and antimicrobial susceptibility pattern of MRSA strains isolated from raw bovine milk sold at local markets in Tanzania. A total of 117 raw milk samples were cultured on Baird-Parker medium to isolate S. aureus and PCR was used for amplification of gltB gene for S. aureus identification and the presence of mecA gene for methicillin-resistant strains. Coagulase-negative (CN) S. aureus were reconfirmed using tube coagulase, DNase, and API Staph tests. MRSA isolates were spa typed whereas antimicrobial susceptibility testing was performed by the disc diffusion method. Forty-six coagulase positives (CP) and two CN S. aureus were identified. Most strains were resistant to penicillin (72%), and 3 isolates: 2 CN S. aureus and 1 coagulase-negative Staphylococci (CNS), were phenotypically resistant to vancomycin, oxacillin, and cefoxitin and were confirmed to carry mecA. Resistance to clindamycin, trimethoprim-sulfamethoxazole, and tetracycline was 23.9%, 30.4%, and 41.3%, respectively. Twelve isolates exhibited multidrug resistance; however, only one mecA positive strain among the three was typeable and belonged to spa type t2603. This study reports for the first time the presence of CN variant of MRSA, which was assigned the spa type t2603, and the presence of multidrug resistant S. aureus isolates from bovine milk in Morogoro, Tanzania.

Curcumin Reverse Methicillin Resistance in Staphylococcus aureus

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Su-Hyun Mun

2014-11-01

Full Text Available Curcumin, a natural polyphenolic flavonoid extracted from the rhizome of Curcuma longa L., was shown to possess superior potency to resensitize methicillin-resistant Staphylococcus aureus (MRSA to antibiotics. Previous studies have shown the synergistic activity of curcumin with β-lactam and quinolone antibiotics. Further, to understand the anti-MRSA mechanism of curcumin, we investigated the potentiated effect of curcumin by its interaction in diverse conditions. The mechanism of anti-MRSA action of curcumin was analyzed by the viability assay in the presence of detergents, ATPase inhibitors and peptidoglycan (PGN from S. aureus, and the PBP2a protein level was analyzed by western blotting. The morphological changes in the curcumin-treated MRSA strains were investigated by transmission electron microscopy (TEM. We analyzed increased susceptibility to MRSA isolates in the presence of curcumin. The optical densities at 600 nm (OD600 of the suspensions treated with the combinations of curcumin with triton X-100 and Tris were reduced to 63% and 59%, respectively, compared to curcumin without treatment. N,N'-dicyclohexylcarbodiimide (DCCD and sodium azide (NaN3 were reduced to 94% and 55%, respectively. When peptidoglycan (PGN from S. aureus was combined with curcumin, PGN (0–125 μg/mL gradually blocked the antibacterial activity of curcumin (125 μg/mL; however, at a concentration of 125 µg/mL PGN, it did not completely block curcumin. Curcumin has a significant effect on the protein level of PBP2a. The TEM images of MRSA showed damage of the cell wall, disruption of the cytoplasmic contents, broken cell membrane and cell lysis after the treatment of curcumin. These data indicate a remarkable antibacterial effect of curcumin, with membrane permeability enhancers and ATPase inhibitors, and curcumin did not directly bind to PGN on the cell wall. Further, the antimicrobial action of curcumin involved in the PBP2a-mediated resistance mechanism was

Co-colonization and clonal diversity of methicillin-sensitive and methicillin-resistant Staphylococcus aureus in sows.

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Fetsch, Alexandra; Roesler, Uwe; Kraushaar, Britta; Friese, Anika

2016-03-15

Methicillin-susceptible Staphylococcus (S.) aureus (MSSA) and methicillin-resistant S. aureus (MRSA) are colonizers of skin and mucosa. In humans, MSSA and MRSA compete for colonization space in the anterior nares of pig farmers; however, it was also shown that MSSA/MRSA co-colonization is common and one clone can be found rather than differing types of MSSA and MRSA. We investigated the colonization and clonality of both, MSSA and MRSA in pigs over a longer time. Eighteen sows were nasally sampled three times every ten weeks. Additionally, environmental samples were taken. Samples were investigated for MSSA and MRSA, respectively. The spa type was defined from up to five MRSA and MSSA isolates found per sample and sampling time; selected isolates were further investigated by microarray. Three sows (16.7%) were completely negative for MSSA and MRSA. Twelve pigs (66.7%) were irregularly positive for both, MSSA and MRSA over the time, whereas seven out of them (38.9%) were simultaneously colonized. CC398 (t034, t011) MRSA and CC9 (t337, t1430, and t13816) MSSA associated spa types were exclusively found. In 44.4% (n=8) of sows up to two different types of MSSA were present at the same time and sample. Strains of the same clonal lineage showed a high genetic identity despite their origin. Highly identic clones were present in sows and their environment. As conclusion, MSSA/MRSA may not exclude each other in the anterior nares of pigs. Pigs may also carry different clones at the same time. Copyright © 2016 Elsevier B.V. All rights reserved.

Modified DNA extraction for rapid PCR detection of methicillin-resistant staphylococci

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Japoni, A.; Alborzi, A.; Rasouli, M.; Pourabbas, B.

2004-01-01

Nosocomial infection caused by methicillin-resistant staphylococci poses a serious problem in many countries. The aim of this study was to rapidly and reliably detect methicillin-resistant-staphylococci in order to suggest appropriate therapy. The presence or absence of the methicillin-resistance gene in 115 clinical isolates of staphylococcus aureus and 50 isolates of coagulase negative staphylococci was examined by normal PCR. DNA extraction for PCR performance was then modified by omission of achromopeptadiase and proteinase K digestion, phenol/chloroform extraction and ethanol precipitation. All isolates with Mic>8 μ g/ml showed positive PCR. No differences in PCR detection have been observed when normal and modified DNA extractions have been performed. Our modified DNA extraction can quickly detect methicillin-resistant staphylococci by PCR. The advantage of rapid DNA extraction extends to both reduction of time and cost of PCR performance. This modified DNA extraction is suitable for different PCR detection, when staphylococci are the subject of DNA analysis

Concomitant genotyping revealed diverse spreading between methicillin-resistant Staphylococcus aureus and methicillin-susceptible Staphylococcus aureus in central Taiwan.

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Ho, Cheng-Mao; Lin, Chien-Yu; Ho, Mao-Wang; Lin, Hsiao-Chuan; Peng, Ching-Tien; Lu, Jang-Jih

2016-06-01

Staphylococcus aureus is a versatile bacterium, which can lead to various infectious diseases. Various molecular typing methods are applied to the evolution and epidemiology surveys of S. aureus, mostly for methicillin-resistant S. aureus (MRSA). However, methicillin-susceptible S. aureus (MSSA) is still an important pathogen, but their molecular typing is evaluated infrequently. Pulsed-field gel electrophoresis (PFGE), spa typing, and detection of five virulent genes for 95 MRSA and 56 MSSA isolates (July-December 2008 and July 2008-December 2009, respectively) during an overlapping period were performed. More diversity was found in MSSA isolates (23 pulsotypes and 25 spa types, excluding 4 new-type and 1 nontypable isolates for spa typing) than in MRSA isolates (19 pulsotypes and 16 spa types, excluding 1 new-type and 1 nontypable isolates for spa typing). By spa typing, t002 (n = 30), t037 (n = 23), t437 (n = 21), t234 (n = 3), t1081 (n = 3), and t1094 (n = 3) were the six major MRSA clones. For MSSA isolates, t189 (n = 13), t437 (n = 4), t084 (n = 3), t213 (n = 3), t701 (n = 3), and t7200 (n = 3) were the six major types. Combining PFGE and spa typing, there were five combinations (pulsotype + spa type) that contained both MRSA and MSSA isolates (pulsotype 9-t437, pulsotype 15-t037, pulsotype 19-t002, pulsotype 21-t002, and pulsotype 28-t1081). For all 151 S. aureus or 95 MRSA isolates, the PFGE typing had more discrimination power, but spa typing had larger discrimination index for 56 MSSA isolates. In conclusion, there were different predominant MRSA and MSSA clones clinically. Continuing longitudinal tracking of molecular typing is necessary for elucidating the evolution of this important clinical pathogen. Copyright © 2014. Published by Elsevier B.V.

Methicillin-resistant Staphylococcus aureus among animals: current overview.

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Aires-de-Sousa, M

2017-06-01

Currently, methicillin-resistant Staphylococcus aureus (MRSA) is a universal threat. After being well established in the healthcare setting, it has emerged in the community among people with no risk factors for MRSA acquisition, therefore imposing a new threat. The subsequent detection of MRSA colonizing or infecting animals as well as in food of animal origin was of major concern, revealing new reservoirs for MRSA. The major MRSA clonal lineages circulating in the different settings, i.e. in hospitals, in the community and among animals, are described here, differentiating between clones colonizing companion and food-chain animals. Particular attention is given to the widely spread livestock-associated MRSA clonal complex (CC) 398, which is mainly associated with professional exposure but may be of high pathogenicity. The recent detection of a mecA homologue, designated mecC, with a wide geographical distribution in Europe, and including a large diversity of hosts (food-chain, companion and wildlife animals and also detected in water samples) adds to the threat. Domestication as well as globalization of the livestock industry have intensified exchanges between human and animal bacteria. We report here several cases of transmission of MRSA between companion or food-chain animals and humans, as well as some MRSA clones of human origin that have adapted to new animal hosts eventually by losing useless virulence factors or acquiring new mobile genetic elements. Copyright © 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

[Study of marine actinomycetes isolated from the central coast of Peru and their antibacterial activity against methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecalis].

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León, Jorge; Aponte, Juan José; Rojas, Rosario; Cuadra, D'Lourdes; Ayala, Nathaly; Tomás, Gloria; Guerrero, Marco

2011-06-01

To determine the antimicrobial potential of marine actinomycetes against drug-resistant pathogens represented by strains of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecalis (VRE). Strains of actinomycetes (29) isolated from marine sediment were evaluated by their characteristics in two culture media and by testing their inhibitory capacity by in vitro antagonism against multi-drug resistant (MDR) pathogenic bacteria for MRSA and VRE. Organic extracts of 3 selected actinomicetes were processed to determine the minimum inhibitory concentration (MIC) of the active compound. Most isolated actinomycetes belong to a homogeneous group of write-gray actinomycetes with a good growth in Marine Agar. The inhibitory rates of the isolates were above 85% for both pathogens with inhibition zones greater than 69 and 78 mm in diameter for MRSA and VRE respectively. Dichloromethane extracts of 3 isolates (I-400A, B1-T61, M10-77) showed strong inhibitory activity of both pathogens, M10-77 being the highest actinomycete strain with antibiotic activity against methicillin-resistant S. aureus ATCC 43300 and vancomycin-resistant E. faecalis ATCC 51299 with a minimum inhibitory concentrations (MIC) of 7.9 and 31.7 μg/ml respectively. Phylogenetic analysis of M10-77 strain showed 99% similarity with the marine species Streptomyces erythrogriseus. Marine sediments of the central coast of Peru, are a source of actinomycetes strains showing high capacity to produce bioactive compounds able to inhibit pathogens classified as multi-drug-resistant such as methicillin-resistant S. aureus and vancomycin-resistant E. faecalis.

Methicillin-resistant staphylococcus aureus isolates in a hospital of shanghai.

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Wang, Xiaoguang; Ouyang, Lin; Luo, Lingfei; Liu, Jiqian; Song, Chiping; Li, Cuizhen; Yan, Hongjing; Wang, Ping

2017-01-24

Methicillin-resistant Staphylococcus aureus (MRSA) strains are now common both in the health care setting and in the community. Active surveillance is critical for MRSA control and prevention. Specimens of patients (200 patients with 1119 specimens) as well as medical staff and hospital setting (1000 specimens) were randomly sampled in a level 2 hospital in Shanghai from September 2011 to August 2012. Isolation, cultivation and identification of S. aureus were performed. Totally, 67 S. aureus strains were isolated. 32 S. aureus strains were isolated from patient samples; 13 (13/32, 40.6%) of the 32 S. aureus isolates were MRSA; sputum sample and patients in the department of general internal medicine were the most frequent specimen and patient group for S. aureus strains isolation. Remaining 35 S. aureus strains were isolated from the medical staff and hospital setting; 20 (20/35, 57.1%) of the 35 S. aureus isolates were MRSA; specimens sampled from doctors and nurses' hands and nose and hospital facilities were the most frequent samples to isolate S. aureus. Resistant and virulent genes detection showed that, all 33 MRSA strains were mecA positive which accounts for 49.3% of the 67 S. aureus strains; 38 isolates were Panton-Valentine leukocidin (PVL) gene positive which accounts for 56.7% of the 67 S. aureus strains; and 17 (17/67, 25.4%) isolates are mecA and PVL genes dual positive. Multidrug-resistant strains of MRSA and PVL positive S. aureus are common in patients, medical staff and hospital setting, the potential health threat is worthy of our attention.

Prevalence of antibiotic resistant coliform bacteria, Enterococcus spp. and Staphylococcus spp. in wastewater sewerage biofilm.

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Lépesová, Kristína; Kraková, Lucia; Pangallo, Domenico; Medveďová, Alžbeta; Olejníková, Petra; Mackuľak, Tomáš; Tichý, Jozef; Grabic, Roman; Birošová, Lucia

2018-03-28

Urban wastewater contains different micropollutants and high number of different microorganisms. Some bacteria in wastewater can attach to the surfaces and form biofilm, which gives bacteria advantage in fight against environmental stress. This work is focused on bacterial community analysis in biofilms isolated from influent and effluent sewerage of wastewater treatment plant in Bratislava. Biofilm microbiota detection was performed by culture-independent and culture-dependent approaches. Composition of bacterial strains was detected by denaturing gradient gel electrophoresis fingerprinting coupled with the construction of 16S rRNA clone libraries. The biofilm collected at the inlet point was characterized primarily by the presence of Pseudomonas sp., Acinetobacter sp. and Janthinobacterium sp. clones, while in the biofilm isolated at outflow of wastewater treatment plant members of Pseudomonas genus were largely detected. Beside this analysis prevalence of antibiotics and resistant coliforms, Enterococcus spp. and Staphylococcus spp. in sewerage was studied. In influent wastewater were dominant antibiotics like azithromycin, clarithromycin and ciprofloxacin. Removal efficiency of these antibiotics notably azithromycin and clarithromycin were 30% in most cases. The highest number of resistant bacteria with predominance of coliforms was detected in sample of effluent biofilm. Multidrug resistant strains in effluent biofilm showed very good ability to form biofilm. Copyright © 2018. Published by Elsevier Ltd.

Empiric guideline-recommended weight-based vancomycin dosing and mortality in methicillin-resistant Staphylococcus aureus bacteremia: a retrospective cohort study

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Hall Ronald G

2012-04-01

Full Text Available Abstract Background No studies have evaluated the effect of guideline-recommended weight-based dosing on in-hospital mortality of patients with methicillin-resistant Staphylococcus aureus bacteremia. Methods This was a multicenter, retrospective, cohort study of patients with methicillin-resistant Staphylococcus aureus bacteremia receiving at least 48 hours of empiric vancomycin therapy between 01/07/2002 and 30/06/2008. We compared in-hospital mortality for patients treated empirically with weight-based, guideline-recommended vancomycin doses (at least 15 mg/kg/dose to those treated with less than 15 mg/kg/dose. We used a general linear mixed multivariable model analysis with variables identified a priori through a conceptual framework based on the literature. Results A total of 337 patients who were admitted to the three hospitals were included in the cohort. One-third of patients received vancomycin empirically at the guideline-recommended dose. Guideline-recommended dosing was not associated with in-hospital mortality in the univariable (16% vs. 13%, OR 1.26 [95%CI 0.67-2.39] or multivariable (OR 0.71, 95%CI 0.33-1.55 analysis. Independent predictors of in-hospital mortality were ICU admission, Pitt bacteremia score of 4 or greater, age 53 years or greater, and nephrotoxicity. Conclusions Empiric use of weight-based, guideline-recommended empiric vancomycin dosing was not associated with reduced mortality in this multicenter study.

Staphylococcus aureus and community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in and around therapeutic whirlpools in college athletic training rooms.

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Kahanov, Leamor; Kim, Young Kyun; Eberman, Lindsey; Dannelly, Kathleen; Kaur, Haninder; Ramalinga, A

2015-04-01

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has become a leading cause of skin and soft tissue infection in the nonhospitalized community. Care of the athletes in athletic training rooms is specifically designed with equipment tailored to the health care needs of the athletes, yet recent studies indicate that CA-MRSA is still prevalent in athletic facilities and that cleaning methods may not be optimal. To investigate the prevalence of Staphylococcus aureus and CA-MRSA in and around whirlpools in the athletic training room. Cross-sectional study. National Collegiate Athletic Association Division I university. Student-athletes (n = 109) consisting of 46 men (42%) and 63 women (58%) representing 6 sports. Presence of MRSA and Staphylococcus aureus in and around the whirlpool structures relative to sport and number of athletes using the whirlpools. We identified Staphylococcus aureus in 22% (n = 52/240) of the samples and MRSA in 0.8% (n = 2/240). A statistically significant difference existed between the number of athletes using the whirlpool and the presence of Staphylococcus aureus in and around the whirlpools (F(2,238) = 2.445, P = .007). However, Staphylococcus aureus was identified regardless of whether multiple athletes used a whirlpool or no athletes used a whirlpool. We did not identify a relationship between the number of athletes who used a whirlpool and Staphylococcus aureus or MRSA density (P = .134). Staphylococcus aureus and MRSA were identified in and around the whirlpools. Transmission of the bacteria can be reduced by following the cleaning and disinfecting protocols recommended by the Centers for Disease Control and Prevention. Athletic trainers should use disinfectants registered by the Environmental Protection Agency to sanitize all whirlpools between uses.

Prevention strategies for methicillin-resistant Staphylococcus aureus (MRSA in Latin America

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Carlos Alvarez

Full Text Available After the first reports of the emergence of methicillin-resistant Staphylococcus aureus (MRSA in the 1970s, numerous measures intended to prevent its transmission were initiated in hospitals. However, in most cases, large-scale measures failed to be implemented and the transmission of MRSA has since led to a global pandemic. Presently, doubts still remain about the best approach to prevent and control MRSA and more often than not, control measures are not implemented. Therefore, we review here the current situation in Latin America with respect to existing policies for control of MRSA, and evaluate the evidence for control measures in hospitals and the community. We look at the risk factors for infection and transmission of MRSA between hospital patients and within specific populations in the community, and at the effect of antibiotic usage on the spread of MRSA in these settings. Finally, we summarize recommendations for the prevention and control of MRSA, which can be applied to the Latin American hospital environment and community setting

Clinical impact of antimicrobial resistance in European hospitals: excess mortality and length of hospital stay related to methicillin-resistant Staphylococcus aureus bloodstream infections.

LENUS (Irish Health Repository)

de Kraker, Marlieke E A

2011-04-01

Antimicrobial resistance is threatening the successful management of nosocomial infections worldwide. Despite the therapeutic limitations imposed by methicillin-resistant Staphylococcus aureus (MRSA), its clinical impact is still debated. The objective of this study was to estimate the excess mortality and length of hospital stay (LOS) associated with MRSA bloodstream infections (BSI) in European hospitals. Between July 2007 and June 2008, a multicenter, prospective, parallel matched-cohort study was carried out in 13 tertiary care hospitals in as many European countries. Cohort I consisted of patients with MRSA BSI and cohort II of patients with methicillin-susceptible S. aureus (MSSA) BSI. The patients in both cohorts were matched for LOS prior to the onset of BSI with patients free of the respective BSI. Cohort I consisted of 248 MRSA patients and 453 controls and cohort II of 618 MSSA patients and 1,170 controls. Compared to the controls, MRSA patients had higher 30-day mortality (adjusted odds ratio [aOR] = 4.4) and higher hospital mortality (adjusted hazard ratio [aHR] = 3.5). Their excess LOS was 9.2 days. MSSA patients also had higher 30-day (aOR = 2.4) and hospital (aHR = 3.1) mortality and an excess LOS of 8.6 days. When the outcomes from the two cohorts were compared, an effect attributable to methicillin resistance was found for 30-day mortality (OR = 1.8; P = 0.04), but not for hospital mortality (HR = 1.1; P = 0.63) or LOS (difference = 0.6 days; P = 0.96). Irrespective of methicillin susceptibility, S. aureus BSI has a significant impact on morbidity and mortality. In addition, MRSA BSI leads to a fatal outcome more frequently than MSSA BSI. Infection control efforts in hospitals should aim to contain infections caused by both resistant and susceptible S. aureus.

Discovery of a 1,2-bis(3-indolyl)ethane that selectively inhibits the pyruvate kinase of methicillin-resistant Staphylococcus aureus over human isoforms.

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Zoraghi, Roya; Campbell, Sara; Kim, Catrina; Dullaghan, Edie M; Blair, Lachlan M; Gillard, Rachel M; Reiner, Neil E; Sperry, Jonathan

2014-11-01

Methicillin-resistant Staphylococcus aureus pyruvate kinase (MRSA PK) has recently been identified as a target for development of novel antibacterial agents. Testing a series of 1,2-bis(3-indolyl)ethanes against MRSA PK has led to the discovery of a potent inhibitor that is selective over human isoforms. Copyright © 2014 Elsevier Ltd. All rights reserved.

Cost Comparison of Linezolid Versus Vancomycin for Treatment of Complicated Skin and Skin-Structure Infection Caused by Methicillin-Resistant Staphylococcus aureus in Quebec

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Martine Pettigrew

2012-01-01

Full Text Available BACKGROUND: In Canada, complicated skin and skin-structure infection (cSSSI caused by methicillin-resistant Staphylococcus aureus (MRSA is usually treated with antibiotics in hospital, with a follow-up course at home for stable patients. The cost implications of using intravenous and oral linezolid instead of intravenous vancomycin in Canadian clinical practice have not been examined.

Community-Acquired Methicillin-Resistant Staphylococcus aureus: The New Face of an Old Foe?

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Udo, Edet E.

2013-01-01

The burden of infections caused by community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is increasing among different patient populations globally. As CA-MRSA has become established in healthcare facilities, the range of infections caused by them has also increased. Molecular characterization of CA-MRSA isolates obtained from different centers has revealed significant diversity in their genetic backgrounds. Although many CA-MRSA strains are still susceptible to non-β-lactam antibiotics, multiresistance to non-β-lactam agents has emerged in some clones, posing substantial problems for empirical and directed therapy of infections caused by these strains. Some CA-MRSA clones have acquired the capacity to spread locally and internationally. CA-MRSA belonging to ST80-MRSA-IV and ST30-MRSA-IV appear to be the dominant clones in the countries of the Gulf Cooperation Council (GCC). The emergence of pandemic CA-MRSA clones not only limits therapeutic options but also presents significant challenges for infection control. Continued monitoring of global epidemiology and emerging drug resistance data is critical for the effective management of these infections. PMID:24051949

Disorganization of cell division of methicillin-resistant Staphylococcus aureus by methanolic extract from Phyllanthus columnaris stem bark

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Adnalizawati, A. Siti Noor; Nazlina, I. [School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Yaacob, W. A. [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

2013-11-27

The in vitro activity of methanolic extract from Phyllanthus columnaris stem bark was studied against Methicillin-resistant Staphylococcus aureus (MRSA) ATCC 43300 and MRSA BM1 (clinical strain) using time-kill curves in conjunction with scanning and transmission electron microscopy. The extract showed more markedly bactericidal activity in MRSA BM1 clinical strain within less than 4 h by 6.25-12.5 mg/mL and within 6 h by 1.56 mg/mL. Scanning electron microscopy of MRSA BM1 revealed distortion of cell whilst transmission electron microscopy revealed disruption in cell wall division.

Disorganization of cell division of methicillin-resistant Staphylococcus aureus by methanolic extract from Phyllanthus columnaris stem bark

International Nuclear Information System (INIS)

Adnalizawati, A. Siti Noor; Nazlina, I.; Yaacob, W. A.

2013-01-01

The in vitro activity of methanolic extract from Phyllanthus columnaris stem bark was studied against Methicillin-resistant Staphylococcus aureus (MRSA) ATCC 43300 and MRSA BM1 (clinical strain) using time-kill curves in conjunction with scanning and transmission electron microscopy. The extract showed more markedly bactericidal activity in MRSA BM1 clinical strain within less than 4 h by 6.25-12.5 mg/mL and within 6 h by 1.56 mg/mL. Scanning electron microscopy of MRSA BM1 revealed distortion of cell whilst transmission electron microscopy revealed disruption in cell wall division

The Plasmin-Sensitive Protein Pls in Methicillin-Resistant Staphylococcus aureus (MRSA Is a Glycoprotein.

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Isabelle Bleiziffer

2017-01-01

Full Text Available Most bacterial glycoproteins identified to date are virulence factors of pathogenic bacteria, i.e. adhesins and invasins. However, the impact of protein glycosylation on the major human pathogen Staphylococcus aureus remains incompletely understood. To study protein glycosylation in staphylococci, we analyzed lysostaphin lysates of methicillin-resistant Staphylococcus aureus (MRSA strains by SDS-PAGE and subsequent periodic acid-Schiff's staining. We detected four (>300, ∼250, ∼165, and ∼120 kDa and two (>300 and ∼175 kDa glycosylated surface proteins with strain COL and strain 1061, respectively. The ∼250, ∼165, and ∼175 kDa proteins were identified as plasmin-sensitive protein (Pls by mass spectrometry. Previously, Pls has been demonstrated to be a virulence factor in a mouse septic arthritis model. The pls gene is encoded by the staphylococcal cassette chromosome (SCCmec type I in MRSA that also encodes the methicillin resistance-conferring mecA and further genes. In a search for glycosyltransferases, we identified two open reading frames encoded downstream of pls on the SCCmec element, which we termed gtfC and gtfD. Expression and deletion analysis revealed that both gtfC and gtfD mediate glycosylation of Pls. Additionally, the recently reported glycosyltransferases SdgA and SdgB are involved in Pls glycosylation. Glycosylation occurs at serine residues in the Pls SD-repeat region and modifying carbohydrates are N-acetylhexosaminyl residues. Functional characterization revealed that Pls can confer increased biofilm formation, which seems to involve two distinct mechanisms. The first mechanism depends on glycosylation of the SD-repeat region by GtfC/GtfD and probably also involves eDNA, while the second seems to be independent of glycosylation as well as eDNA and may involve the centrally located G5 domains. Other previously known Pls properties are not related to the sugar modifications. In conclusion, Pls is a glycoprotein and

Polymerase chain reaction fingerprints of methicillin-resistant Staphylococcus aureus clinical isolates in Greece are related to certain antibiotypes.

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Bartzavali-Louki, Christina; Dimitracopoulos, George; Spiliopoulou, Iris

2003-06-01

Characterization of clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and representatives of three MRSA clones from other hospitals was performed by arbitrarily primed polymerase chain reaction (AP-PCR) and antibiotic susceptibility patterns. All isolates were mecA-positive and two main antibiotypes have been characterized. Two major clones were identified with AP-PCR related to the aforementioned antibiotypes. The combination of antibiotypes with AP-PCR patterns successfully identified the two major clones in our hospital, which are identical with the MRSA clones previously characterized in Athens and in Central and North Greece.

A Disposable Polymer Lab-On-A-Slide For Point-Of-Care Diagnostics Of Methicillin-Resistant Staphylococcus Aureus (Mrsa)

DEFF Research Database (Denmark)

Bu, Minqiang; R. Perch-Nielsen, Ivan; Skov, Julia

2013-01-01

This paper reports the design, fabrication and experimental verification of a polymer microfluidic labon-a-slide for rapid detection of methicillin-resistant Staphylococcus aureus (MRSA). MRSA cells were captured in a lysis chamber using magnetic beads, followed by thermal lysis. The released DNA...... was transferred into a second chamber for polymerase chain reaction (PCR) amplification. Fluidic control in the device was accomplished by pneumatic actuation of a micropump and five microvalves integrated on the device. The mecA gene from MRSA was successfully amplified by real-time PCR within 35 min. Presence...

The effect of rapid screening for methicillin-resistant Staphylococcus aureus (MRSA) on the identification and earlier isolation of MRSA-positive patients.

LENUS (Irish Health Repository)

Creamer, Eilish

2010-04-01

(1) To determine whether rapid screening with polymerase chain reaction (PCR) assays leads to the earlier isolation of patients at risk for methicillin-resistant Staphylococcus aureus (MRSA) colonization, (2) to assess compliance with routine MRSA screening protocols, (3) to confirm the diagnostic accuracy of the Xpert MRSA real-time PCR assay (Cepheid) by comparison with culture, and (4) to compare turnaround times for PCR assay results with those for culture results.

Epidemiologic Genotyping of Methicillin-Resistant Staphylococcus aureus (MRSA by Pulsed-Field Gel Electrophoresis (PFGE

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Maja Ostojić

2008-08-01

Full Text Available čćStaphylococcus aureus has long been recognized as one of the leading cause of hospital infections all over the world. Increased frequency of methicillin-resistant Staphylococcus aureus (MRSA in hospitalized patients and possibility of vancomycin resistance requires rapid and reliable characterization of isolates and control of MRSA spread in hospitals. Typing of isolates helps to understand pathogenesis and route of the hospital pathogen spread. In this study in the analysis of an outbreak of MRSA infections in one surgical ward, we used pulsed-field gel electrophoresis (PFGE as a method of typing. PFGE revealed one epidemic strain type A in 13 out of 16 patients, and another two types (type B in two patients and type C in one patient. Discussing the typing results in the ward has changed the admission policy of patients with infected vascular ulcers who were then cured as outpatients, and admitted for surgery after that. This policy resulted with the stopping of the outbreak; during next 2,5 year there was no further MRSA outbreak in the ward. PFGE also showed subtypes which enabled the insight into dynamics of MRSA strain changes during the outbreak. PFGE could be recommended as a screening method in the MRSA outbreak analysis. Because of it’s high discriminatory power still remains the gold standard for MRSA typing

Clinical features and molecular characteristics of childhood community-associated methicillin-resistant Staphylococcus aureus infection in a medical center in northern Taiwan, 2012.

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Wang, Hong-Kai; Huang, Chun-Yen; Huang, Yhu-Chering

2017-07-05

Since first reported in 2002, the rate of methicillin-resistant Staphylococcus aureus (MRSA) among childhood community-associated (CA) S. aureus infection in Taiwan increased significantly up to 2005. There have been no reports on this issue since then. We prospectively collected clinical S. aureus isolates from the patients Taiwan were MRSA. Though CC59 is still the prevalent community clone, several new clones emerged in northern Taiwan.

Graphene oxide-silver nanocomposite as a promising biocidal agent against methicillin-resistant Staphylococcus aureus.

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de Moraes, Ana Carolina Mazarin; Lima, Bruna Araujo; de Faria, Andreia Fonseca; Brocchi, Marcelo; Alves, Oswaldo Luiz

2015-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) has been responsible for serious hospital infections worldwide. Nanomaterials are an alternative to conventional antibiotic compounds, because bacteria are unlikely to develop microbial resistance against nanomaterials. In the past decade, graphene oxide (GO) has emerged as a material that is often used to support and stabilize silver nanoparticles (AgNPs) for the preparation of novel antibacterial nanocomposites. In this work, we report the synthesis of the graphene-oxide silver nanocomposite (GO-Ag) and its antibacterial activity against relevant microorganisms in medicine. GO-Ag nanocomposite was synthesized through the reduction of silver ions (Ag(+)) by sodium citrate in an aqueous GO dispersion, and was extensively characterized using ultraviolet-visible absorption spectroscopy, X-ray diffraction, thermogravimetric analysis, X-ray photoelectron spectroscopy, and transmission electron microscopy. The antibacterial activity was evaluated by microdilution assays and time-kill experiments. The morphology of bacterial cells treated with GO-Ag was investigated via transmission electron microscopy. AgNPs were well distributed throughout GO sheets, with an average size of 9.4±2.8 nm. The GO-Ag nanocomposite exhibited an excellent antibacterial activity against methicillin-resistant S. aureus, Acinetobacter baumannii, Enterococcus faecalis, and Escherichia coli. All (100%) MRSA cells were inactivated after 4 hours of exposure to GO-Ag sheets. In addition, no toxicity was found for either pristine GO or bare AgNPs within the tested concentration range. Transmission electronic microscopy images offered insights into how GO-Ag nanosheets interacted with bacterial cells. Our results indicate that the GO-Ag nanocomposite is a promising antibacterial agent against common nosocomial bacteria, particularly antibiotic-resistant MRSA. Morphological injuries on MRSA cells revealed a likely loss of viability as a result of the

Phenotypic and genetic characteristics of fluoroquinolone- and methicillin-resistant Staphylococcus aureus.

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Moreno-Flores, Antonio; Potel-Alvarellos, Carmen; Otero-Fernández, Susana; Álvarez-Fernández, Maximiliano

2017-07-20

Fluoroquinolone resistance in methicillin-resistant Staphylococcus aureus (MRSA) has increased in recent years. The objective of this study was to characterise two MRSA populations, one susceptible to fluoroquinolones and other resistant identifying the clonal types and the differential characteristics of both MRSA populations. Molecular typing using PFGE, MLST, spa and SSCmec was performed on 192 MRSA strains isolated from 2009 to 2011, 49 only oxacillin-resistant (OX-R) and 143 oxacillin and levofloxacin-resistant (OX-R-LEV-R). Mutations that conferred resistance to fluoroquinolones, hypermutable phenotypes and the presence of eight microbial surface components recognising adhesive matrix molecules (MSCRAMMs) were also studied. A statistically significant increase in the OX-R-LEV-R phenotype was observed (p<0.05). The most common clone of the OX-R isolates was sequence type (ST) 8 (32.6%), followed by ST72 (26.5%) and ST5 (26.5%). In the OX-R-LEV-R phenotype, the ST5 clone was the most common (65.7%), followed by ST72 (15.4%), and ST125 (12.6%). All isolates except the ST398 clone carried the SCCmecIVc. Clones ST5, ST72, ST125, and ST30 had hypermutable phenotypes. The ST72 clone and the ST30 clone in the OX-R phenotype harboured the highest number of MSCRAMMs. ST5 and ST72 clones were the most frequent clones identified in OX-R-LEV-R phenotype. Both clones showed a hypermutable phenotype that favours their selection as the fluoroquinolone resistant clones. The genetic relationships identified indicate that OX-R-LEV-R clones have evolved from OX-R MRSA clones. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

Direct detection of methicillin resistance in Staphylococcus aureus in blood culture broth by use of a penicillin binding protein 2a latex agglutination test.

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Qian, Qinfang; Venkataraman, Lata; Kirby, James E; Gold, Howard S; Yamazumi, Toshiaki

2010-04-01

We studied the utility of performing a penicillin binding protein 2a latex agglutination (PBP-LA) assay directly on Bactec blood culture broth samples containing Staphylococcus aureus to rapidly detect methicillin resistance. The sensitivity, specificity, positive predictive value, and negative predictive value of this method were 94.1%, 97.5%, 98%, and 92.9%, respectively.

Direct Detection of Methicillin Resistance in Staphylococcus aureus in Blood Culture Broth by Use of a Penicillin Binding Protein 2a Latex Agglutination Test▿

OpenAIRE

Qian, Qinfang; Venkataraman, Lata; Kirby, James E.; Gold, Howard S.; Yamazumi, Toshiaki

2010-01-01

We studied the utility of performing a penicillin binding protein 2a latex agglutination (PBP-LA) assay directly on Bactec blood culture broth samples containing Staphylococcus aureus to rapidly detect methicillin resistance. The sensitivity, specificity, positive predictive value, and negative predictive value of this method were 94.1%, 97.5%, 98%, and 92.9%, respectively.

Comparison of real-time PCR with disk diffusion, agar screen and E-test methods for detection of methicillin-resistant Staphylococcus aureus.

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Shariati, Laleh; Validi, Majid; Tabatabaiefar, Mohammad Amin; Karimi, Ali; Nafisi, Mohammad Reza

2010-12-01

Methicillin-resistant Staphylococcus aureus (MRSA) is a nosocomial pathogen. Our main objective was to compare oxacillin disk test, oxacillin E-test, and oxacillin agar screen for detection of methicillin resistance in S. aureus, using real-time PCR for mecA as the "gold standard" comparison assay. 196 S. aureus isolates were identified out of 284 Staphylococcus isolates. These isolates were screened for MRSA with several methods: disk diffusion, agar screen (6.0 μg/ml), oxacillin E-test, and real-time PCR for detection of mecA gene. Of the 196 S. aureus isolates tested, 96 isolates (49%) were mecA-positive and 100 isolates (51%) mecA-negative. All methods tested had a statistically significant agreement with real-time PCR. E-test was 100% sensitive and specific for mecA presence. The sensitivity and specificity of oxacillin agar screen method were 98 and 99%, respectively and sensitivity and specificity of oxacillin disk diffusion method were 95 and 93%, respectively. In the present study, oxacillin E-test is proposed as the best phenotypic method. For economic reasons, the oxacillin agar screen method (6.0 μg/ml), which is suitable for the detection of MRSA, is recommended due to its accuracy and low cost.

Characterization of mannitol-fermenting methicillin-resistant staphylococci isolated from pigs in Nigeria

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Clifford C. Ugwu

2015-09-01

Full Text Available This study was conducted to determine the species distribution, antimicrobial resistance pheno- and genotypes and virulence traits of mannitol-positive methicillin-resistant staphylococci (MRS isolated from pigs in Nsukka agricultural zone, Nigeria. Twenty mannitol-positive methicillin-resistant coagulase-negative staphylococcal (MRCoNS strains harboring the mecA gene were detected among the 64 Staphylococcus isolates from 291 pigs. A total of 4 species were identified among the MRCoNS isolates, namely, Staphylococcus sciuri (10 strains, Staphylococcus lentus (6 strains, Staphylococcus cohnii (3 strains and Staphylococcus haemolyticus (one strain. All MRCoNS isolates were multidrug-resistant. In addition to β-lactams, the strains were resistant to fusidic acid (85%, tetracycline (75%, streptomycin (65%, ciprofloxacin (65%, and trimethoprim/sulphamethoxazole (60%. In addition to the mecA and blaZ genes, other antimicrobial resistance genes detected were tet(K, tet(M, tet(L, erm(B, erm(C, aacA-aphD, aphA3, str, dfrK, dfrG, catpC221, and catpC223. Thirteen isolates were found to be ciprofloxacin-resistant, and all harbored a Ser84Leu mutation within the QRDR of the GyrA protein, with 3 isolates showing 2 extra substitutions, Ser98Ile and Arg100Lys (one strain and Glu88Asp and Asp96Thr (2 strains. A phylogenetic tree of the QRDR nucleotide sequences in the gyrA gene revealed a high nucleotide diversity, with several major clusters not associated with the bacterial species. Our study highlights the possibility of transfer of mecA and other antimicrobial resistance genes from MRCoNS to pathogenic bacteria, which is a serious public health and veterinary concern.

Characterization of mannitol-fermenting methicillin-resistant staphylococci isolated from pigs in Nigeria.

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Ugwu, Clifford C; Gomez-Sanz, Elena; Agbo, Ifeoma C; Torres, Carmen; Chah, Kennedy F