Case of sepsis caused by multidrug-resistant neutropenic-phase Pseudomonas aeruginosa treated successfully with antibiotic combination therapy

Multidrug-resistant Pseudomonas aeruginosa (MDRP), defined as Pseudomonas aeruginosa resistant to aminoglycosides, carbapenems, and fluoroquinolones, has emerged as an increasingly problematic cause of hospital-acquired infection. With parenteral colistin unavailable in Japan, effective antimicrobial options are severely limited. We report a case of MDRP bacteremia successfully treated with antibiotic combination therapy screened by a 'Break-point Checkerboard Plate'. A 54-year-old man with malignant lymphoma who became febrile 9 days after a recent course of chemotherapy had a neutrophil count of 176/microL. Treatment with meropenem and vancomycin was ineffective and high fever persisted. Methicillin-resistant Staphylococcus aureus (MRSA) and MDRP were isolated from blood culture and combination therapy with aztreonam and amikacin was selected for MDRP based on 'Break-point Checkerboard Plate' results. Linezolid was used for MRSA. The patient recovered successfully from MDRP and MRSA sepsis.     

Detection of mupirocin resistant staphylococci from patients treated with mupirocin

Susceptibility testing of mupirocin (MUP) was performed by an agar dilution method according to the National Committee for Clinical Laboratory Standard (NCCLS) to detect the MUP resistance. A total of 434 isolates of methicillin-resistant staphylococci were examined and all of 205 isolates of methicillin-resistant Staphylococcus aureus (MRSA) from 43 hospitals nationwide in 1993 were sensitive to MUP. However, MUP resistance emerged among 228 isolates [185 isolates (88 cases) of MRSA and 43 isolates (28 cases) of methicillin-resistant coagulase negative staphylococci (MR-CNS)] from nasal swabs of patients with MUP treatment between Sep 1996 and Feb 2000 in the Nagoya University Hospital. The high-level MUP resistance (MIC > or = 512 micrograms/mL) was isolated from two patients, one isolate of MRSA and four of S. hominis, respectively. Low-level MUP resistance (MIC 8-128 micrograms/mL) was isolated from three patients, 11 isolates of MRSA, one of S. chromogenes and five of S. epidermidis, respectively. The mupA which encodes the MUP resistant isoleucyl-tRNA synthetase (IRS) were investigated by PCR in these MUP resistant isolates. The mupA was detected only in high-level MUP resistant S. hominis, but not detected in high-level MUP resistant MRSA and low-level MUP resistant isolates. We also investigated the characteristics of the patients with MUP resistance. All of MUP resistant staphylococci were isolated after initiation of MUP treatment. Four patients with MUP resistant MRSA and low-level MUP resistant MR-CNS had MRSA infectious disease and MUP resistant strains were successfully eradicated with vancomycin treatment in two patients. MUP high-level resistant S. hominis, has emerged after MUP treatment for eradication of MRSA. Clinical guidelines for the prudent use of MUP should be generally adopted with careful monitoring of emergence of MUP resistance.     

Virulence Characteristics of <Emphasis Type="Italic">Escherichia coli</Emphasis> Strains Causing Asymptomatic Bacteriuria

Background: The objective of this study was to examine the expression of Escherichia coli virulence-associated factors among the strains isolated from a group of women with a history of recurrent urinary tract infections (UTIs), in whom asymptomatic bacteriuria (ABU) was detected at follow-up, and from a group of children without a history of previous UTI, in whom ABU was detected during the screening. Possible differences between the virulence potential of these strains were investigated.Materials and Methods: Hemolysin production, the ability to adhere to Buffalo green monkey cell line and hemagglutination (HA) ability of the ABU-associated E. coli strains were tested. E. coli strains isolated from patients with acute recurrent UTIs served as a comparison. Results: The well-known low virulence of strains isolated from patients with ABU was demonstrated. In contrast to strains isolated from recurrent uncomplicated UTIs, the ABU-associated strains were mostly nonhemolytic (75%), nonadherent (70%) and lacked HA ability (61%). HA ability was significantly more common among the strains isolated from children without a history of UTI than among the strains isolated from women with recurrent UTIs (² = 9.97, p < 0.01), whereas the adherence and hemolytic abilities did not differ between the two ABU groups.Conclusion: A further prospective study is needed to determine whether the HA ability is the predictor of subsequent symptomatic UTI.     

Study of the cases with multidrug-resistant Pseudomonas aeruginosa by sputum culture]

We evaluated the clinical features of multidrug-resistant Pseudomonas aeruginosa cases determined by sputum culture between April, 2005 and December, 2006. The clinical features of most cases were: (1) pneumonia in the elderly with cerebrovascular diseases, (2) previous administration of carbapenems and antipseudomonal cephems, (3) PIPC, CAZ and ISP sensitve MDRP, (4) MRSA was isolated concurrently, (5) not necessary of therapy against MDRP, (6) good outcome.     

Handheld computer surveillance: shoe-leather epidemiology in the "palm" of your hand

BACKGROUND: Although urinary tract infections (UTIs) are the most common nosocomial infection, active UTI surveillance is often not feasible for infection control departments. METHODS: As part of an ongoing urinary catheter evaluation, we investigated the accuracy and cost-effectiveness of using handheld personal digital assistants (PDA) and computer-based UTI surveillance in comparison with traditional surveillance of UTIs among medical intensive care unit (MICU) patients. From September 22, 2000, to October 22, 2000, an infection control practitioner (ICP) actively surveyed all MICU patients who had a urinary catheter to determine criteria for a nosocomial UTI as defined by the Centers for Disease Control and Prevention (CDC). Research assistants visited the unit each day to determine which patients had urinary catheters, and this information was uploaded to a database designed for laboratory-based UTI surveillance. Patients with a urinary catheter were included if admitted to the MICU for >48 hours and excluded if symptoms developed <48 hours after admission. RESULTS: Both data collection methods identified 8 UTIs within the 1-month period, with 3 UTIs meeting inclusion criteria. Traditional surveillance required 8 hours weekly, whereas the PDA-computer surveillance required 1-and-a-half hours weekly. Traditional surveillance correctly attributed all 3 UTIs to the MICU. The PDA-computer surveillance incorrectly attributed the location of 2 of the UTIs. In both cases, the UTI occurred less than 48 hours after the patient was transferred from the MICU. CONCLUSION: Our data demonstrate that PDA surveillance detects nosocomial UTIs efficiently and is a novel, timesaving technique that realizes a cost savings in the first year.     

Effect of silver-coated urinary catheters: efficacy, cost-effectiveness, and antimicrobial resistance

BACKGROUND: Urinary tract infections (UTIs) are the most common nosocomial infection experienced by patients in United States hospitals and are responsible for significant morbidity and excess hospital costs. The purpose of this study was to determine the efficacy of a silver alloy, hydrogel-coated, urinary catheter in the prevention of catheter-associated UTI, to assess the cost effectiveness of the coated catheter, and to test for the emergence of silver-resistance in urinary microbial isolates. METHODS: A 2-year prospective surveillance study in 10 patient care units was conducted to determine the rate of catheter-associated UTI. Historic control data was utilized to assess the effect of the coated catheter. A cost-effectiveness analysis was conducted using a range of cost estimates. Silver susceptibility was determined for microbes responsible for catheter-associated UTI. RESULTS: Data were analyzed using a Poisson regression model. The rate of catheter-associated UTI fell from 6.13/1000 catheter-days during the period 1999-2000 to 2.62/1000 catheter-days during 2001-2002 ( P = .002). Calculated cost savings varied widely. Modest savings were achieved at the realistic lower cost estimates. No silver-resistant microbes were recovered in the susceptibility tests. CONCLUSIONS: The introduction of a silver alloy, hydrogel-coated urinary catheter was associated with a significant decline in nosocomial UTI and cost savings over the range of cost estimates. Silver-resistant urinary pathogens were not recovered from patients experiencing catheter-associated UTI during the study period.     

Temporal changes in the prevalence of community-acquired antimicrobial-resistant urinary tract infection affected by Escherichia coli clonal group composition.

BACKGROUND: The changing prevalence of drug-resistant community-acquired urinary tract infection (UTI) is often attributed to local antimicrobial drug use or prescribing practices. However, recent molecular epidemiologic studies of community-acquired UTI suggest that other factors may play a greater role. METHODS: We conducted a multiyear, cross-sectional study to characterize temporal changes in the prevalence of drug-resistant community-acquired UTI at a university community in California. During four 3.5-month sampling periods, urine samples from patients consecutively presenting to the university health service with symptoms of UTI were cultured for Escherichia coli. Antimicrobial susceptibility and genotyping tests of the E. coli isolates were performed. RESULTS: We recovered 780 E. coli isolates from 1667 patients with UTI. The prevalence of trimethoprim-sulfamethoxazole, ciprofloxacin, and nitrofurantoin resistance showed no trend over the 4 periods. The prevalence of ampicillin resistance decreased significantly over the last 2 study periods. A single clonal group accounted for 75% of this decrease. Enterobacterial repetitive intergenic consensus 2 PCR-based genotyping revealed that only 4 large clonal groups accounted for 52% of the UTIs resistant to trimethoprim-sulfamethoxazole, ciprofloxacin, or nitrofurantoin. No initially pansusceptible clonal groups gained resistance over time. CONCLUSIONS: This study revealed no obvious trend in the prevalence of drug-resistant community-acquired UTI in a single community. Prevalence at any time was influenced by a small number of E. coli clonal groups. This observation suggests that the introduction of strains that are drug resistant into a community plays a greater role in changing the prevalence of drug-resistant UTI than does the drug use or prescribing habits in that community.     

Current antibiotic therapy for isolated urinary tract infections in women

BACKGROUND: Sulfa antibiotics, such as a combination product of trimethoprim and sulfamethoxazole, have traditionally been the drugs of choice for urinary tract infections (UTIs) and remained the most common treatment as recently as a decade ago. However, increasing sulfa resistance among Escherichia coli may have led to changes in prescribing practices. METHODS: We used the 2000-2002 National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey to obtain nationally representative data on antibiotics prescribed for women with isolated outpatient UTIs following visits to physicians' offices, hospital clinics, and emergency departments (n = 2638). Logistic regression was used to determine predictors of quinolone use. RESULTS: Quinolones were more commonly prescribed than sulfa antibiotics in each year evaluated. In the most recent year of data, quinolones were prescribed in 48% and sulfas in 33% of UTI visits (P<.04). Quinolones were significantly more likely to be prescribed to older patients and in visits occurring in the Northeast; however, no difference in quinolone prescribing was seen when evaluating insurance status, setting, race, ethnicity, health care provider type, and year. Approximately one third of the quinolones used were broader-spectrum agents. CONCLUSIONS: Quinolones have surpassed sulfas as the most common class of antibiotic prescribed for isolated outpatient UTI in women. Few significant predictors of quinolone use exist, suggesting that the increase is not confined to a certain subset of patients. This pervasive growth in quinolone use raises concerns about increases in resistance to this important class of antibiotics.     

甘肃武威地区2006～2007年常见葡萄球菌感染及耐药状况分析

目的了解甘肃武威地区常见葡萄球菌感染及耐药状况,以更好地指导临床用药。方法将2006～2007年甘肃省武威市医院采集的320株葡萄球菌采用常规方法分离,用Vitek-32全自动微生物分析仪进行菌种鉴定及药敏试验。结果分离到金黄色葡萄球菌192株,表皮葡萄球菌86株,溶血性葡萄球菌42株。其中耐甲氧西林葡萄球菌213株,包括耐甲氧西林金黄色葡萄球菌118株（36．9％）,耐甲氧西林表皮葡萄球菌60株（18．8％）,耐甲氧西林溶血性葡萄球菌35株（10．9％）。耐甲氧西林金黄色葡萄球菌、表皮葡萄球菌和溶血性葡萄球菌均成多重耐药特征,未发现耐万古霉素、替考拉丁的葡萄球菌。结论耐甲氧西林葡萄球菌检出率呈明显上升趋势,合理使用抗生素,尤其万古霉素的使用,已成为当务之急。     

Sporadic isolations of a multi-drug resistant Pseudomonas aeruginosa clone during a 14-month epidemic in a general hospital in Hiroshima

Background

During 2005–2007, we experienced sporadic isolations of multidrug-resistant (MDRP) Pseudomonas aeruginosa from wards in a general hospital in Hiroshima. The objective of this study was to analyze epidemiology relationships and the mode of spread of the strains.

Methods

Clonality was assessed using pulsed-field gel electrophoresis (PFGE) and serotyping. MICs were determined using the microdilution broth method. Investigations of the affected patients’ movements and environmental sampling from the affected wards were conducted.

Results

An abrupt increase in MDRP isolations began at the end of 2005 and ended in February 2007. A total of 25 MDRP strains were sporadically isolated from nine wards. Fourteen strains were genotypically and serologically identical. Analysis of the patients’ movements identified that six of the 14 MDRP-positive patients became positive for MDRP when they were in the intensive care unit (ICU), and two became positive after the patients moved from the ICU to another nursing unit. Four MDRP strains were isolated from patients who did not stay in the ICU and were in ward E6, which had the second highest number of isolations. In July 2006, environmental sampling of the hospital identified a toilet brush in ward E6 that was contaminated with MDRP that was genotypically and serologically identical to the clinical isolates.

Conclusions

Our study suggests that the sporadic increase in MDRP isolates during 2005–2007 in the general hospital in Hiroshima was due to an epidemic of an MDRP clone. Continuity and spread of infection was probably due to cross infection and contamination in the hospital with the MDRP strain.     

Antibiotic Resistance in Pediatric Urinary Tract Infections

Urinary tract infections (UTIs) are a common problem in pediatric patients. Resistance to common antibiotic agents appears to be increasing over time, although resistance rates may vary based on geographic region or country. Prior antibiotic exposure is a pertinent risk factor for acquiring resistant organisms during a first UTI and recurrent UTI. Judicious prescribing of antibiotics for common pediatric conditions is needed to prevent additional resistance from occurring. Complex pediatric patients with histories of hospitalizations, prior antibiotic exposure, and recurrent UTIs are also at high risk for acquiring UTIs due to extended spectrum beta-lactamase-producing organisms. Data regarding the impact of in vitro antibiotic susceptibility testing interpretation on UTI treatment outcomes is lacking.     

Increasing antimicrobial resistance and the management of uncomplicated community-acquired urinary tract infections.

Community-acquired urinary tract infections (UTIs) are among the most common bacterial infections in women. Therapy for these infections is usually begun before results of microbiological tests are known. Furthermore, in women with acute uncomplicated cystitis, empirical therapy without a pretherapy urine culture is often used. The rationale for this approach is based on the highly predictable spectrum of etiologic agents causing UTI and their antimicrobial resistance patterns. However, antimicrobial resistance among uropathogens causing community-acquired UTIs, both cystitis and pyelonephritis, is increasing. Most important has been the increasing resistance to trimethoprim-sulfamethoxazole (TMP-SMX), the current drug of choice for treatment of acute uncomplicated cystitis in women. What implications do these trends have for treatment of community-acquired UTIs? Preliminary data suggest that clinical cure rates may be lower among women with uncomplicated cystitis treated with TMP-SMX when the infecting pathogen is resistant to TMP-SMX. Women with pyelonephritis also have less bacterial eradication and lower clinical cure rates when treated with TMP-SMX for an infection that is resistant to the drug. Therefore, in the outpatient setting, identifying risk factors for TMP-SMX resistance and knowing the prevalence of TMP-SMX resistance in the local community are important steps in choosing an appropriate therapeutic agent. When choosing a treatment regimen, physicians should consider such factors as in vitro susceptibility, adverse effects, cost-effectiveness, and selection of resistant strains. Using a management strategy that takes these variables into account is essential for maintaining the safety and efficacy of treatment for acute UTI.     

Susceptibility to vancomycin of methicillin-resistant Staphylococcus aureus isolated in a university hospital in Japan

Intravenous vancomycin was approved in 1991 in Japan and has been widely used for treatment of infections caused by methicillin-resistant Staphylococcus aureus (MRSA). Consequently, ever since the initial discovery of vancomycin intermediate-resistant S. aureus in Japan, the vancomycin resistance of this organism has been a great concern in clinical settings. We investigated whether vancomycin resistance had emerged in MRSA isolated in our hospital since the approval of the use of intravenous vancomycin. Vancomycin susceptibility was evaluated on the basis of minimum inhibitory concentrations determined by the agar dilution method and a heterogeneous resistance examination. The median minimum inhibitory concentration of the 69 MRSA strains isolated in 1988 and the 74 isolated in 1998 was 0.75 microgram/ml and 1.0 microgram/ml, respectively (p < 0.001), however, all of the strains were classified in the susceptible group. None of them was an MRSA heterogeneously resistant to vancomycin (hetero-VRSA), which has been defined as a strain having a 1/10(6) or greater heterogeneously resistant subpopulation to vancomycin. In another set of investigations, no hetero-VRSA were found among 12 other MRSA strains isolated after intravenous administration of vancomycin for 14 or more days (range: 14 to 77 days). We conclude that while the use of intravenous vancomycin may have slightly lowered the vancomycin susceptibility of MRSA in our hospital, the decrease in so small that it may not be significant clinically. In addition, no hetero-VRSA were found in our hospial.     

Report of questionnaire survey for methicillin-resistant Staphylococcus aureus and penisillin-resistant Streptococcus pneumoniae between 1998 and 2000 in the Kinki district

Kinki Infection Working Group made an annual (1998-2000) comparative study of an epidemiological investigation for Staphylococcus aureus and Streptococcus pneumoniae in the Kinki district. The number of S. aureus and methicillin-resistant S. aureus (MRSA) isolated decreased for three years, but the isolation frequencies of MRSA has not changed which was approximately 60%. All strains of MRSA were not resistant to vancomysin (VCM) and teicoplanin (TEIC), and the frequencies of resistance to sulfamethoxazole-trimethoprim (ST) and arbekacin (ABK) were 0.1 to 0.7% and 1.9 to 3.1%, respectively. On the other hand, the number of S. aureus and penicillin-resistant S. pneumoniae (PRSP) isolated did not show a consistent tendency, but the isolation frequencies of PRSP has increased for three years. All strains of PRSP were sensitive to vancomycin (VCM), but the frequencies of resistance to cefaclor and other some antibiotics have increased.     

下呼吸道感染金葡菌耐药性分析

目的调查我院住院病人下呼吸道感染金黄色葡萄球菌（SA）的耐药现状。方法对101例下呼吸道感染sA的住院病人临床资料进行分析,并比较甲氧西林敏感金黄色葡萄球菌（MSSA）与耐甲氧西林金黄色葡萄球菌（MRSA）对抗生素的耐药性差异。结果共101例下呼吸道感染患者,分离出MRSA71例,分离率70．30％。下呼吸道sA感染发生于基础疾病较多,接受侵入性操作,长时间使用抗生素的患者;药敏结果显示,MRSA对多种抗菌药物的产生高度耐药,且耐药率明显高于MSSA（P〈0．01）,但对替加环素、万古霉素、利奈唑胺敏感率为100％。结论下呼吸道感染sA多发生于危险因素较多的患者;MRSA分离率高,对常用抗菌药物呈多重耐药。     

Methicillin resistance among Trinidadian isolates of community and hospital strains of Staphylococcus aureus and their patterns of resistance to non-beta-lactam antibiotics

The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) strains in Trinidad and the extent of their resistance to other antimicrobial agents in hospital-acquired and community-acquired infections were evaluated over a 2-year period. A total of 450 S. aureus strains were isolated from different patients. The prevalence of methicillin resistance among S. aureus strains was 9.8% (44/450). The proportion of MRSA isolated from hospital sources and community sources was 12.5% (38/305) and 4.1% (6/145), respectively (P < 0.05). The resistant rates of MRSA to the non-beta-lactam antibiotics were as follows: 93.2% resistance to tetracycline, 68.2% to erythromycin, 61.4% to gentamicin, 45.5% to co-trimoxazole, and 20.5% to ciprofloxacin. No MRSA resistant to vancomycin was observed in this study. Study results showed significant increases in MRSA in hospital, 2% in 1995 to 12.5% in 1998 (P < 0.05), and community, 0% in 1995 to 4.1% in 1998 (P < 0.05). It has become apparent that infection control and surveillance initiatives must be focused now on the community in order to monitor and limit the spread of this new and expanding reservoir of MRSA.     

Diaper cystitis as recurrent cause of urinary infections in geriatric community hospital

AIM: Chronic cystitis in diaper-dependent elderly patients can be a causative pathology for recurrent urinary tract infections (UTIs) in community hospitals. METHODS: We analyzed hospital infections to determine causative organisms from January 2007 to December 2009 in patients in a long-term care hospital. The reading causes of hospital infections were UTIs (30.4%), aspiration pneumonia (CAP; 26%) and hospital-acquired pneumonia (HAP; 17.2%). Of a total of 3,097 hospital infections over the investigation period, UTIs were the most common (n=940, 30.4%) followed by CAP (n=809, 26%) and HAP (n=533, 17.2%). Of 278 UTIs in 2007, the causative strains were Escherichia coli (n=106, 38%), Enterococcus faecalis (n=44, 16%), Proteus mirabilis (n=31, 11%), α-hemolytic streptococcus (n=22, 8%), and β-hemolytic streptococcus (n=14, 5%). Extended spectrum β-lactamase (n=14, 13%) strains were noted in 106 patients with Escherichia coli. We then retrospectively examined the records of 110 diaper dependent elderly patients, (medical words, n=52, mix-care wards, n=68) for UTIs over the same study period. Of these 16 (14.5%) had no UTIs at any time, 12 (11%) were infected 50% of the time, 17 (15.5%) were infected 51% to 99% of the time and 65 (59%) were infected 100% of the time. The UTI rate was not correlated with bladder function or between the 2 wards. We treated bacterial cystitis with antibiotics for 3-5 days but these were unsuccessful. Antiseptics worked temporarily, but recurrence or re-infection always occurred. It remains unknown if diapers are a potential cause of chronic cystitis in dependent elderly patients. The clinical dilemma of whether recurrent diaper cystitis should be treated and prohibit the growth and spread of drug-resistant strains, remains challenging.     

'Break-point Checkerboard Plate' for screening of appropriate antibiotic combinations against multidrug-resistant Pseudomonas aeruginosa

Increase of multiple drug resistant Pseudomonas aeruginosa (MDRP) is becoming a serious problem in the clinical setting. Although the checkerboard method to determine FIC index and synergistic effects of antibiotic combinations is useful, it is not well adapted to a routine test, mainly because of its time-consuming and labor-intensive nature. Here we report 'Break-point Checkerboard Plate', in which breakpoint concentrations, such as 'S' (sensitive) and 'I' (intermediate), were combined in a microtiter plate with 8 antibiotics, including carbapenem, aminoglycoside and fluoroquinolone. The results obtained from 12 strains of MDRP demonstrated a strong synergistic effect of some antibiotic combinations at clinically relevant concentrations. Our data suggest a usefulness of 'Break-point Checkerboard Plate' to screen appropriate antibiotic combinations against drug resistant organisms, including MDRP.     

烧伤患者创面感染金黄色葡萄球菌分离株耐药性及流行病学分析

目的对河北地区烧伤患者创面分离的120株金黄色葡萄球菌进行mecA和SCCmec检测分析MRSA耐药机制,为临床合理用药提供依据。方法在2009~2013年收治的烧伤患者创面中分离的120株金黄色葡萄球菌,采用头孢西丁纸片法进行MRSA筛选,对mecA基因,SCCmec和spa基因进行PCR扩增以及分型。结果 120株金黄色葡萄球菌中有74株为MRSA,占61.7%。药敏试验显示,MRSA对16种临床常见抗生素耐药率,超过85%的有7种,依次为苯唑西林（98.6%）,青霉素（96.0%）,环丙沙星（94.6%）,阿莫西林和头孢唑林（89.2%）,亚胺培南（87.8%）,庆大霉素（85.1%）,另有1株对万古霉素耐药。结论本组金黄色葡萄球菌MRSA检出率较高,并表现出较高的耐药性。MRSA具有的多重耐药性mecA基因密切关系。     

Genotyping of methicillin-resistant Staphylococcus aureus isolated from inpatients and medical workers in orthopaedics ward

Methicillin-resistant Staphylococcus aureus (MRSA) strains were isolated from the inpatients in orthopaedics ward hospitalized from March 1998 to November 2000, hospital environments, medical workers and the inpatients transferred from TCC (Trauma and Critical Care Center). Genotype by pulsed field gel electrophoresis (PFGE) and biotype according to the production of coagulase, enterotoxin and toxic-shock syndrome toxin-1 (TSST-1) were determined for the MRSA strains to analyze the infection source and transmission route of the infection. Out of 673 S. aureus strains isolated from the inpatients, 390 strains (57.5%) were MRSA. In 89 medical workers in orthopaedics ward, MRSA were isolated in 23 (25.8%) and 7 (7.9%) workers from nasal cavity and hand, finger, respectively. In contrast, no MRSA was isolated from hospital environments. Eighty MRSA strains (80%) from the inpatients and 8 MRSA strains (75%) from the medical workers were shown to have same biotype; coagulase II-enterotoxin C-TSST-1 (+) (II-C- (+)). MRSA strains isolated from the inpatients were grouped into 24 types according to PFGE patterns, and types 17 (17 strains), 12 (13 strains), 1 (8 strains), 4 (8 strains) and 13 (6 strains) were dominant among the MRSA strains isolated. It was shown that MRSA strains with the same PFGE genotype were detected at the same time in the different wards. In addition, MRSA strains isolated from medical workers were all PFGE genotypes 1 and 4. MRSA strain isolated from a new inpatient had a different PFGE type from the 24 kinds of genotype. These results suggest that the involvement of the medical workers might be important as infection source and for transmission of MRSA in hospital.