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

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

Thesis (Ph. D.)--Illinois State University, 1999. / Title from title page screen, viewed July 20, 2006. Dissertation Committee: Brian J. Wilkinson (chair), Radheshyam K. Jayaswal, Alan J. Katz, Anthony J. Otsuka, David L. Williams. Includes bibliographical references and abstract. Also available in print.

published_or_final_version / Community Medicine / Master / Master of Public Health

No description available.

published_or_final_version / Nursing Studies / Master / Master of Nursing

Staphylococci strains are among the most widespread multidrug-resistant nosocomial pathogens in Canada. Rapid and accurate identification and epidemiological typing of methicillin-resistant S. aureus (MRSA) and its discrimination from coagulase-negative staphylococci (CNS) and glycopeptide-intermediate S. aureus (GISA) are crucial for appropriate therapy and for monitoring and limiting intra- and inter-hospital spread of epidemic MRSA strains. Although pulsed-field gel electrophoresis and polymerase chain reaction methods for the identification of MRSA are reliable, they are technically demanding, time-consuming and inappropriate for routine clinical diagnosis. Moreover, no reliable method exists for discrimination of epidemic MRSA from sporadic MRSA and from GISA strains. The objective of the research described in this thesis was to investigate whether Fourier transform infrared (FTIR) spectroscopy could be used to distinguish MRSA from methicillin-susceptible S. aureus, borderline oxacillin-resistant S. aureus (BORSA), CNS, including methicillin-resistant CNS, and GISA. The application of FTIR spectroscopy for epidemiological typing of Canadian epidemic MRSA (CMRSA) strains as well as their discrimination from sporadic MRSA was also assessed. FTIR spectra were recorded from intact stationary-phase cells grown on Universal Medium (UM™) and deposited and dried on a ZnSe optical window, normalized, and converted to first-derivative spectra. Various chemometric approaches were employed to cluster the different phenotypes of staphylococci species and to subtype five CMRSA strains based on the similarity of their infrared spectral fingerprints in narrow spectral regions selected by visual inspection and by employing a singularvalue decomposition (SVD) algorithm. Pairwise separation of MRSA from MSSA, BORSA, CNS, MRCNS, and GISA was accomplished by using principal component analysis (PCA), self-organizing maps (SOM), and the K-nearest neighbors (KNN) algorithm. These chemometric techniques were also successfully employed for epidemiological typing of the five CMRSA strains and their discrimination from sporadic MRSA strains using a combination of different optimal spectral regions selected by SVD. These results demonstrate that FTIR spectroscopy has considerable potential as a rapid method for the identification of different phenotypes of staphylococci and epidemiological typing of MRSA.

Thesis (Ph.D.). / Written for the Dept. of Food Science and Agricultural Chemistry, Macdonald College of McGill University. Title from title page of PDF (viewed 2008/08/04). Includes bibliographical references.