Case of fulminant leptospirosis in a renal transplant patient.

We present a case of fulminant leptospirosis that was acquired in the suburban area by a 48-year-old male renal transplant recipient. He developed acute renal and hepatic failure with profound jaundice. Spirochetes were identified on liver biopsy. Weil's disease was suspected, and the diagnosis was further supported by a positive serum Leptospira interrogans icterohaemorrhagiae antibody titer. Unfortunately, he suffered from recurrent lower gastrointestinal bleeding, had a prolonged hospital course, and eventually succumbed to overwhelming sepsis. This case is the third report to our knowledge of leptospirosis in a renal transplant recipient in the English literature.

Epidemiology and outcomes of community-associated methicillin-resistant Staphylococcus aureus infection.

Over a 2-year period (2003 to 2005) patients with community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) and community-acquired methicillin-susceptible Staphylococcus aureus (CA-MSSA) infections were prospectively identified. Patients infected with CA-MRSA (n = 102 patients) and CA-MSSA (n = 102 patients) had median ages of 46 and 53 years, respectively; the most common sites of infection in the two groups were skin/soft tissue (80 and 93%, respectively), respiratory tract (13 and 6%, respectively), and blood (4 and 1%, respectively). Fourteen percent of patients with CA-MRSA infections and 3% of patients with CA-MSSA infections had household contacts with similar infections (P < 0.01). Among the CA-MRSA isolates, the pulsed-field gel electrophoresis (PFGE) groups detected were USA300 (49%) and USA100 (13%), with 27 PFGE groups overall; 71% of the isolates were staphylococcal chromosome cassette mec (SCCmec) type IV, 29% were SCCmec type II, and 54% had the Panton-Valentine leucocidin (PVL) gene. Among the CA-MSSA isolates there were 33 PFGE groups, with isolates of the USA200 group comprising 11%, isolates of the USA600 group comprising 11%, isolates of the USA100 group comprising 10%, and isolates of the PVL type comprising 10%. Forty-six and 18% of the patients infected with CA-MRSA and CA-MSSA, respectively, were hospitalized (P < 0.001). Fifty percent of the patients received antibiotic therapy alone, 5% received surgery alone, 30% received antibiotics and surgery, 3% received other therapy, and 12% received no treatment. The median durations of antibiotic therapy were 12 and 10 days in the CA-MRSA- and CA-MSSA-infected patients, respectively; 48 and 56% of the patients in the two groups received adequate antimicrobial therapy, respectively (P < 0.001). The clinical success rates of the initial therapy in the two groups were 61 and 84%, respectively (P < 0.001); recurrences were more common in the CA-MRSA group (recurrences were detected in 18 and 6% of the patients in the two groups, respectively [P < 0.001]). CA-MRSA was an independent predictor of clinical failure in multivariate analysis (odds ratio, 3.4; 95% confidence interval, 1.7 to 6.9). In the community setting, the molecular characteristics of the S. aureus strains were heterogeneous. CA-MRSA infections were associated with a more adverse impact on outcome than CA-MSSA infections.

Multicenter evaluation of ethambutol susceptibility testing of mycobacterium tuberculosis by agar proportion and radiometric methods.

Reproducibility of ethambutol (EMB) susceptibility test results for Mycobacterium tuberculosis has always been difficult for a variety of reasons, including the narrow range between the critical breakpoint for EMB resistance and the MIC for susceptible strains, borderline results obtained with the BACTEC 460TB method, the presence of microcolonies determined using the agar proportion (AP) method, and a lack of agreement between these two testing methods. To assess the frequency of these problems, M. tuberculosis drug susceptibility data were collected in a multicenter study involving four laboratories. Resistant, borderline, and susceptible isolates were shared among the laboratories to measure interlaboratory test agreement. Half of isolates determined by BACTEC 460TB to be resistant were determined to be susceptible by the AP method. Isolates determined to be resistant to EMB by both BACTEC 460TB and AP methods were almost always resistant to isoniazid. Results from isolates tested by the BACTEC 460TB method with an EMB concentration of 3.75 micro g/ml in addition to the standard 2.5 micro g/ml did not show improved agreement by the AP method. While these results do not indicate that the AP method is more accurate than the BACTEC 460TB method, laboratories should not report EMB monoresistance based on BACTEC 460TB results alone. Monoresistance to EMB should only be reported following confirmation by the AP method. Microcolonies could not be confirmed as resistant by the BACTEC 460TB method or by repeat testing with the AP method and do not appear to be indicative of resistance.

Bovine tuberculosis in Michigan wildlife.

White-tailed deer in Michigan are now recognized as a reservoir host of bovine tuberculosis (TB). It has been determined that the most likely cause of bovine TB infection in the deer is from congregating in artificially high numbers at feed sites. The presence of a wildlife reservoir of TB in Michigan poses a serious threat to the control and eradication programs that are now in their final stages in the United States.

Multicenter evaluation of a nonweekend reading schedule for radiometric pyrazinamide susceptibility testing of Mycobacterium tuberculosis.

Pyrazinamide (PZA) is an integral component of the short-course chemotherapy regimen for tuberculosis. The BACTEC 460TB PZA susceptibility test for Mycobacterium tuberculosis with a daily (D) reading schedule has been available for more than 10 years, but weekend laboratory staffing is necessary. A nonweekend (NW) reading schedule has not been validated in a multicenter study. This prospective multicenter study compares the interlaboratory reproducibility of PZA susceptibility results by following both the D and NW schedules. A total of 181 cultures were shared among four laboratories. Isolates were selected based on resistance or borderline resistance to at least one streptomycin-isoniazid-rifampin-ethambutol drug or PZA. One laboratory used a D reading schedule, and three laboratories used a NW schedule. Both reading schedules are based on the standard BACTEC 460TB PZA protocol. With the NW schedule, the growth index (GI) is not available for test interpretation on Saturday, Sunday, and Monday. Of the 181 shared cultures, 154 were found to be susceptible by all laboratories, 19 were found to be resistant, and 8 had discordant results. The overall pairwise interlaboratory agreement was 97.7%. The discrepancies were not associated with the type of reading schedule used. However, the median control GI was significantly higher for the NW schedule (321) than for the D schedule (259) (P < 0.0001) although results were available on average in about 7 days from setup for both schedules. These results show that the NW schedule is a suitable alternative for laboratories that do not read and interpret PZA susceptibility tests on weekends.

Human salmonellosis associated with young poultry from a contaminated hatchery in Michigan and the resulting public health interventions, 1999 and 2000.

Although approximately 95% of disease caused by nontyphoidal salmonella is transmitted by foodborne vehicles, four documented salmonella outbreaks in the 1990s have been traced to contact with young poultry. No environmental studies of source hatcheries were completed. This case-control study was performed by comparing culture-confirmed Salmonella Infantis in Michigan residents, identified between May and July 1999, with two age- and neighbourhood-matched controls. Eighty environmental and bird tissue samples were collected from an implicated hatchery; all salmonella isolates underwent pulsed-field gel electrophoresis (PFGE) analysis. The study included 19 case-patients sharing the same PFGE subtype and 37 matched controls. Within 5 days before illness onset, 74% of case-patients resided in households raising young poultry compared with 16% of controls (matched OR 19.5; 95% CI 2.9, 378.1). Eight hatchery samples yielded Salmonella Infantis with PFGE subtypes matching the patients' isolates. This investigation identified birds from a single hatchery as the source of human illness and confirmed the link by matching PFGE patterns from humans, birds and the hatchery environment. Subsequent public health interventions reduced, but did not eliminate, transmission of poultry-associated salmonellosis. Five additional PFGE-linked cases were identified in Spring 2000, necessitating quarantine of the hatchery for depopulation, cleaning and disinfection.

PCR fragment length polymorphism analysis of vancomycin-resistant Enterococcus faecium.

In this study, the glycopeptide resistance element, Tn1546, in 124 VanA Enterococcus faecium clinical isolates from 13 Michigan hospitals was evaluated using PCR fragment length polymorphism. There were 26 pulsed-field gel electrophoresis (PFGE) types, which consisted of epidemiologically related and unrelated isolates from separate patients (1992 to 1996). Previously published oligonucleotides specific for regions in the vanA gene cluster of Tn1546 were used to amplify vanRS, vanSH, vanHAX, vanXY, and vanYZ. The glycopeptide resistance element, Tn1546, of E. faecium 228 was used as the basis of comparison for all the isolates in this study. Five PCR fragment length patterns were found, as follows. (i) PCR amplicons were the same size as those of EF228 for all genes in the vanA cluster in 19.4% of isolates. (ii) The PCR amplicon for vanSH was larger than that of EF228 (3.7 versus 2.3 kb) due to an insertion between the vanS and vanH genes (79.2% of isolates). (iii) One isolate in a unique PFGE group had a vanSH amplicon larger than that of EF228 (5.7 versus 2.3 kb) due to an insertion in the vanS gene and an insertion between the vanS and vanH genes. (iv) One isolate did not produce a vanSH amplicon, but when vanS and vanH were amplified separately, both amplicons were the same size as those as EF228. (v) One isolate had a vanYZ PCR product larger than that of EF228 (2.8 versus 1.6 kb). This study shows that in a majority of the VanA E. faecium isolates, Tn1546 is altered compared to that of EF228. A total of 79.2% of the study isolates had the same-size insertion between the vanS and vanH genes. The results of this study show dissemination of an altered Tn1546 in heterologous VanA E. faecium in Michigan hospitals.

Emergence of vancomycin resistance in Staphylococcus aureus. Glycopeptide-Intermediate Staphylococcus aureus Working Group.

BACKGROUND: Since the emergence of methicillin-resistant Staphylococcus aureus, the glycopeptide vancomycin has been the only uniformly effective treatment for staphylococcal infections. In 1997, two infections due to S. aureus with reduced susceptibility to vancomycin were identified in the United States. METHODS: We investigated the two patients with infections due to S. aureus with intermediate resistance to glycopeptides, as defined by a minimal inhibitory concentration of vancomycin of 8 to 16 microg per milliliter. To assess the carriage and transmission of these strains of S. aureus, we cultured samples from the patients and their contacts and evaluated the isolates. RESULTS: The first patient was a 59-year-old man in Michigan with diabetes mellitus and chronic renal failure. Peritonitis due to S. aureus with intermediate resistance to glycopeptides developed after 18 weeks of vancomycin treatment for recurrent methicillin-resistant S. aureus peritonitis associated with dialysis. The removal of the peritoneal catheter plus treatment with rifampin and trimethoprim-sulfamethoxazole eradicated the infection. The second patient was a 66-year-old man with diabetes in New Jersey. A bloodstream infection due to S. aureus with intermediate resistance to glycopeptides developed after 18 weeks of vancomycin treatment for recurrent methicillin-resistant S. aureus bacteremia. This infection was eradicated with vancomycin, gentamicin, and rifampin. Both patients died. The glycopeptide-intermediate S. aureus isolates differed by two bands on pulsed-field gel electrophoresis. On electron microscopy, the isolates from the infected patients had thicker extracellular matrixes than control methicillin-resistant S. aureus isolates. No carriage was documented among 177 contacts of the two patients. CONCLUSIONS: The emergence of S. aureus with intermediate resistance to glycopeptides emphasizes the importance of the prudent use of antibiotics, the laboratory capacity to identify resistant strains, and the use of infection-control precautions to prevent transmission.

Molecular analysis of glycopeptide-resistant Enterococcus faecium isolates collected from Michigan hospitals over a 6-year period.

The purpose of this study was to evaluate the molecular relatedness of clinical isolates of glycopeptide-resistant Enterococcus faecium isolates collected from hospitals in Michigan. A total of 379 isolates used in this study were all vancomycin-resistant E. faecium isolates collected from 28 hospitals and three extended-care facilities over a 6-year period from 1991 to 1996. For the 379 isolates, there were 73 pulsed-field gel electrophoresis (PFGE) strain types. Within strain types, there were as many as six restriction fragment differences. Most isolates (70%) belonged to six strain types, which were designated M1 (36%), M2 (3%), M3 (18%), M4 (6%), M10 (4%), and M11 (3%). PFGE strain M1 was cultured from 135 patients in 13 hospitals during the period 1993 to 1996. Strain type M2 was cultured from 11 patients in two hospitals during the period 1991 to 1992 and was not observed after 1992. Strain type M3 was cultured from 70 patients in 10 hospitals during the period of 1994 to 1996. Both M4 and M10 were cultured from 23 patients in three hospitals and from 15 patients in two hospitals, respectively, during 1995 to 1996. M11 was cultured from 13 patients in four hospitals during 1996. A total of 23 of 28 hospitals had evidence of clonal dissemination of some isolates. Plasmid content and hybridization analysis done on 103 isolates from one hospital and two affiliated extended-care facilities indicated that the strains contained from one to eight plasmids. Mating experiments indicated transfer of vancomycin resistance from 94 of these isolates into plasmid-free E. faecium GE-1 at transfer frequencies of <10(-9) to 10(-4). Gentamicin resistance and erythromycin resistance were cotransferred at various frequencies. A probe for the vanA gene hybridized to the plasmids of 23 isolates and to the chromosomes of 72 isolates. A probe for the vanB gene hybridized to the chromosomes of 8 isolates. The results of this study suggest inter- and intrahospital dissemination of vancomycin-resistant E. faecium strains over a 6-year period in southeastern Michigan. The majority of isolates studied belonged to the same few PFGE strains, indicating that clonal dissemination was responsible for most of the spread of resistance that occurred.

Culture-confirmed reinfection of a person with different strains of Borrelia burgdorferi sensu stricto.

In recent years, the utility of serum-based diagnostic testing for Lyme disease has improved substantially; however, recovery by culture of the bacterium from skin biopsies of suspected patients is still the only definitive laboratory test. Reinfection of patients has been assumed to occur but as yet has not been documented by serial isolates from the same person. We present a case of culture-confirmed reinfection of a patient in Menominee County, Michigan. Borrelia burgdorferi was isolated from the skin punch biopsy specimens during each episode of erythema migrans (EM) and was subjected to molecular strain typing, genetic analysis of two outer surface protein genes, protein profile analysis, and serum antibody response testing. Results show that these isolates are distinct strains of the bacterium and that the two episodes of EM were caused by independent infections. This report describes the documented, culture-confirmed reinfection of a human by two different strains of B. burgdorferi.

Genetic relatedness of Burkholderia (Pseudomonas) cepacia isolates from five cystic fibrosis centers in Michigan.

Burkholderia cepacia isolates from patients with cystic fibrosis (CF) attending five CF centers were studied for relatedness by cellular fatty acid methyl esters (FAME) and by chromosomal DNA restriction analysis. Twenty-eight of 32 (87.5%) isolates tested were grouped in cluster group 1 based on their FAME profiles. DNA analysis revealed that 29 of 32 (90.6%) B. cepacia isolates from five CF centers had one closely related DNA pattern. To examine strain variation over a time period, FAME profiles and DNA patterns of isolates from serial cultures on seven patients from center D were studied. For four patients, all serial B. cepacia isolates belonged to a single FAME cluster group; for the remaining three patients, all serial isolates belonged to any two of the four cluster groups. On serial culture isolates, a single DNA pattern (pattern A) was found in 31 of 32 isolates demonstrating a close genetic relatedness. These data corroborate the observations that the majority of patients colonised with B. cepacia in a CF center harbor strains genetically closely related as determined by FAME profiles and DNA patterns.

Outbreak of histoplasmosis among employees in a paper factory--Michigan, 1993.

In December 1993, four reported cases of histoplasmosis among employees in a Michigan pulp paper factory prompted an investigation. A cohort of employees was surveyed to identify additional cases. A case of acute histoplasmosis was defined as an influenza-like illness in a plant employee with the onset of illness during October or November 1993 and laboratory evidence of recent infection with Histoplasma capsulatum. Among the 96 employees surveyed, 18 persons met the case definition; all of these had illness onset during the last week of October in 1993. The attack rate among maintenance employees (16 of 53 [30%]) was much greater than that among nonmaintenance employees (2 of 43 [5%]) (relative risk = 6.5; 95% confidence interval = 1.6 to 26.7; P = 0.003). On October 22, a dry, windy day, one maintenance worker swept bird guano, approximately 10 cm deep, from an adjacent roof < 20 m from the maintenance building. The disturbance of the bird guano was the likely event which caused this outbreak. H. capsulatum remains an important pathogen among immunocompetent hosts. We recommended that the plant authorities (i) discourage birds from roosting at the facility and (ii) use safe procedures for the cleanup and disposal of soil contaminated with bird droppings.

Outbreak of Shigella flexneri linked to salad prepared at a central commissary in Michigan.

In August 1992, the Michigan Department of Public Health was notified of a cluster of persons with Shigella flexneri infections, all of whom had eaten at different outlets of a single restaurant chain. The chain prepared many foods at a central kitchen. A matched case-control study to determine risk factors for illness among patrons of the restaurant chain was undertaken. An inspection of the commissary and a review of commissary inspection and employee records were conducted. Of the 46 patients identified, 44 had eaten tossed salad versus 33 of the 71 controls (matched odds ratio = 56.9; 95 percent confidence interval 5.0, 648.1). Improper salad preparation techniques were used, and the salad preparation area had not been inspected in several years. Some salad preparers had been ill shortly before the outbreak but continued to work. The greater use of central kitchens could lead to larger outbreaks of illness related to improper food handling. Raw vegetables are a potential vehicle for transmission of shigellosis. Coordination of all agencies responsible for inspecting commissaries should be assured. Assuring restriction of ill food handlers will require management to take an active role in identification of ill employees and in the development of incentives to report illness.

Isolation of Borrelia burgdorferi from two patients in Michigan.

Borrelia burgdorferi was isolated from skin biopsy specimens of erythema chronicum migrans lesions on two individuals residing in Menominee County, Michigan, in 1992. To our knowledge, these are the first two cases of culture-confirmed Lyme disease in Michigan. In spite of prompt treatment and resolution of illness, antibodies to B. burgdorferi were detectable for at least 3 months in both patients. Both specimens were obtained at different rural medical practices, thus demonstrating that with adequate laboratory support it is feasible to confirm a diagnosis of acute Lyme disease by culture in rural health care settings.

Bronchoscopy-associated Mycobacterium xenopi pseudoinfections.

Mycobacterium xenopi typically accounts for less than 0.3% of all clinical mycobacterial isolates. Over a 37-mo period, 21 (35%) of 60 mycobacterial isolates from a Michigan hospital were identified as M. xenopi. Hospital, laboratory, and bronchoscopy records were reviewed to determine case characteristics, develop a case series, and calculate procedure-specific M. xenopi isolation rates. A case-control study was conducted to elucidate aspects of the bronchoscopy procedure associated with M. xenopi isolation. Bronchoscope cleaning procedures were reviewed, and hospital water systems were cultured. Four isolates were from three patients with disease attributable to M. xenopi. Of the other isolates, specimens obtained by bronchoscopy were more likely to yield M. xenopi than were specimens obtained by other routes (relative risk, 9.7; 95% confidence intervals, 3.2, 29.6). Bronchoscopes were disinfected in a 0.13% glutaraldehyde-phenate and tap-water bath and then were rinsed in tap water. Water from the hot water tank supplying this area yielded M. xenopi. Mycobacteria were cultured from bronchoscopes after disinfection. M. xenopi in the tap water appears to have contaminated the bronchoscopes during cleaning. Adequate disinfection of contaminated bronchoscopes and careful collection of specimens to avoid contamination with contaminated water are essential, both for limiting diagnostic confusion caused by mycobacterial pseudoinfections and for reducing risks of disease transmission.

Legionella lansingensis sp. nov. isolated from a patient with pneumonia and underlying chronic lymphocytic leukemia.

A Legionella-like organism, strain 1677-MI-H, was isolated from the bronchoscopy washings of a patient with pneumonia who had a 2-year history of progressive, chronic lymphocytic leukemia. The growth characteristics, cellular fatty acids, and ubiquinone content of the isolate were consistent with those for Legionella spp. The isolate was serologically distinct in the slide agglutination test with absorbed antisera. DNA hybridization studies showed that strain 1677-MI-H (ATCC 49751) represents a new Legionella species which is named Legionella lansingensis.

Antibacterial properties of investigational, new, and commonly used antibiotics against isolates of Pseudomonas cepacia in Michigan.

Microdilution antimicrobial susceptibility testing was performed with 73 isolates of Pseudomonas cepacia collected from the sputum of patients throughout Michigan with cystic fibrosis. Susceptibility testing was done using new and investigational antibiotics (loracarbef, cefixime, cefpirome, desacetyl-cefotaxime, cefpodoxime, cefmetazole, cefepime, cefprozil, and fleroxacin) and commonly used antibiotics (ceftazidime, mezlocillin, piperacillin, ciprofloxacin, tobramycin, and amikacin). Ceftazidime was the most active antibiotic, and 91.8% of isolates were susceptible to it with MIC50 and MIC90 values of < or = 4 and 16 micrograms/ml, respectively. For mezlocillin, piperacillin, and ciprofloxacin 84.9, 89 and 39.7% of the isolates, respectively, were mostly moderately susceptible. Loracarbef, cefixime, cefprozil, cefmetazole, cefepime, fleroxacin, cefpodoxime, tobramycin, and amikacin did not show activity against P. cepacia. For cefpirome and desacetylcefotaxime 24.7 and 60.3% of the isolates, respectively, were moderately susceptible. Both MIC50 and MIC90 were > 32 micrograms/ml for cefpirome and 32 and > 64 micrograms/ml for desacetylcefotaxime.