Reproduction de : Thèse doctorat : Médecine. Biologie cellulaire : Reims : 2006. / Titre provenant de l'écran-titre. Bibliogr. p.140-158.

Reproduction de : Thèse d'exercice : Médecine vétérinaire : Toulouse 3 : 2007. / Titre provenant de l'écran titre. Bibliogr. p. 130-137.

Thesis (M.S.)--University of Hawaii at Manoa, 2005. / Includes bibliographical references (leaves 160-171). Also available via World Wide Web.

Thesis (M.S.)--Ball State University, 2009. / Title from PDF t.p. (viewed on Nov. 30, 2009). Includes bibliographical references (p. 61-67).

published_or_final_version / Microbiology / Master / Master of Philosophy

published_or_final_version / Microbiology / Master / Master of Medical Sciences

Background Methicillin resistant Staphylococcus aureus (MRSA) is endemic in healthcare settings in many countries of the world. Patients who have acquired MRSA serve as a source of transmission by contamination of their surrounding environments. Numerous studies illustrate that many different inanimate surfaces in hospitals can become a reservoir for MRSA. Objectives The objective of this study is to examine the presence of MRSA on environmental surfaces and its relationship between patients’ acquisition of MRSA by studying their molecular characteristics. Methodology The near-patient surfaces of 30 MRSA positive patients, 30 control patients and the ward environments were sampled from June 2011 to September 2011. The swabs were enriched and cultured for the presence of MRSA. The MRSA isolates obtained from environmental samples and from the clinical samples of the patients were then characterized by Spa typing. Results The MRSA found in case patients and control patients’ environmental surfaces was 97% (29/30) and 40% (12/30) respectively. Environmental surfaces that were highly contaminated by MRSA positive patients were bed sheets (70%), followed by pillows (55%), patient bed frames (52%) and patient lockers (52%). On the environmental surfaces other than the near-patient areas, ambulatory chair armrests had the highest amount of MRSA (21%), followed by fax machines which accounted for 14%. Among the 216 MRSA isolates (30 clinical isolates and 151 environmental isolates), eight spa types were found and the most predominant spa type was t1081 (63.3%) followed by t032 (17.6%) and t037 (7.4%). 27 patients were found to have the MRSA isolates with same spa type in the clinical samples and their surrounding environments. The agreement between the MRSA isolated from the clinical sample of patients and their surrounding environment was 93.1%. Conclusion Identical isolates were recovered from the patient and their environment (93.1%) which suggests possible environmental contamination of the ward cubicles, possibly contributing to endemic MRSA. More effective and rigorous use of current approaches to cleaning and decontamination is required and consideration of newer technologies to eradicate MRSA. / published_or_final_version / Microbiology / Master / Master of Medical Sciences

Methicillin-resistant Staphylococcus aureus (MRSA) is an important and common pathogen causing community- and healthcare-associated infection. Culture methods were used for identification of MRSA for a long period of time, however it spends a lot of time on incubation and 1 to 2 days is needed to obtain the identification and antibiogram. Molecular tests were developed in the past decades and different genes were used. In this study a Staphylococcus aureus-specific gene, sau gene was designed and accompanied with mecA gene to detect the presence of MRSA in 322 nasal swabs from Tuen Mun Hospital. To evaluate the performance of in-house RT-PCR, samples were run in parallel with LightCycler? MRSA Advanced test and BBLTM CHROMagar? MRSA. 75 (23%) of samples were MRSA positive. The sensitivities and specificities of in-house RT-PCR and LightCycler? MRSA Advanced test were 76.7%/ 89.2% and 87.8%/ 96.6% respectively. The mean processing time for a batch of 32 samples by CHROMagar, in-house RT-PCR and LightCycler? MRSA Advanced test were 48.9 hours, 134.4 mins and 149.8 mins. In-house RT-PCR showed comparable performance and short turnaround time. sau gene can be used with mecA gene for the detection of MRSA in nasal swab. / published_or_final_version / Medicine / Master / Master of Medical Sciences

No description available.

Viable bacteria have been found on environmental surfaces, including washed and unwashed clothing, and places that come into contact with laundry. Under certain conditions, clothing contaminated with pathogenic organisms may present a health risk to the laundry handler. This research project focused on i) evaluating Staphylococcus aureus and MRSA survival using front-load and top-load washing machines; ii) determining relative microbial levels on new, disposable, laundered and unlaundered hospital scrubs; iii) characterizing the relative hygiene of public and apartment laundromat surfaces; and iv) developing a quantitative risk assessment for laundry handlers.Standard microbial evaluation techniques were used to identify and quantify a variety of microorganisms on fabrics and environmental surfaces, including HPC bacteria, S. aureus, MRSA, total coliforms and Escherichia coli. S. aureus and MRSA were exclusively used during evaluation of bacteria reduction levels achieved by front- and top-load washers.Results from this research indicate:i) Washing in either a top- or front-load washer affords a 5 - 6 log10 reduction of S. aureus and MRSA when detergent is used. If complete drying and/or bleach are also employed, a 6 - 7 log10 reduction is achieved and few organisms remain.ii) Bacteria cross-contamination of other fabrics within a laundry load is common for both types of washers and between loads on the interior of top-load washers.iii) Significantly fewer bacteria (p=0.044) were detected on hospital-laundered scrubs than on home-laundered scrubs.iv) Laundromat surfaces can be contaminated with substantial numbers of bacteria and the potential exists for transfer of bacteria from a past user to the next laundromat patron.v) The risk of acquiring a S. aureus infection after handling unwashed laundry contaminated with an initial S. aureus level of 106 CFU/cm2 was estimated to be 0.59 infections per person per year. The estimated risk became negligible if handling washed laundry.