Outbreak caused by tobramycin-resistant Pseudomonas aeruginosa in a bone marrow transplantation unit.

Between May and August 1995, 5 patients in a bone marrow transplantation (BMT) ward developed bacteremia caused by Pseudomonas aeruginosa resistant to tobramycin (TRPA). Previously, isolates of TRPA had been limited to patients who were treated in 1 intensive care unit (ICU) of this tertiary care teaching hospital in Helsinki, Finland. To study whether the outbreak was caused by a single or multiple strains of P. aeruginosa, 102 isolates of TRPA from clinical samples obtained from different hospital units and 22 isolates obtained from the hospital environment were characterized by pulsed-field gel electrophoresis. All isolates from hematological patients produced 1 unique fragment pattern, which was also isolated from 3 ICU patients before the BMT ward outbreak began as well as from 5 shower heads in the BMT ward. The outbreak in the BMT ward was successfully controlled by eradicating the probable environmental source--contaminated hand showers--but the endemic infections continued in the ICU.

Epidemiological typing of Candida albicans from bloodstream infections by restriction enzyme analysis.

Candida albicans blood culture isolates (n = 142) from 130 patients treated in 7 acute care hospitals in Southern Finland between 1986 and 1995 were typed by restriction enzyme analysis (REA) with EcoRI and MspI. REA revealed 118 distinct DNA types: 13 were detected in > 1 patient and 105 DNA types were unique. Patients with identical DNA types were not temporally or geographically clustered. Among 11 patients with more than 1 C. albicans isolate during 1 episode of fungemia the DNA type remained the same, except in 1 patient. These results indicate that REA is a powerful tool for the epidemiological typing of C. albicans infections.

Low virulence of Escherichia coli strains causing urinary tract infection in renal disease patients.

The distribution of urinary bacterial species was determined and the virulence factors of Escherichia coli urinary strains analysed by molecular and phenotyping methods in episodes of urinary tract infection in renal disease patients (n =68) in comparison with other immunocompromised patients (n =59) and non-immunocompromised patients (n =21). Escherichia coli was isolated in 116 (78%) of the 148 patients, being the species most frequently isolated in all groups (75% of renal disease patients, 76% of other immunocompromised patients, 95% of non-immunocompromised patients). All other pathogens showed a similar distribution in the renal disease and other immunocompromised patient groups. All virulence factors of Escherichia coli tested for (genes for G adhesins, expression of MR adhesins, production of haemolysin, presence of certain O and K antigens) were found more often in non-immunocompromised than in immunocompromised patients. The factors allowing the highest degree of discrimination between immunocompromised and non-immunocompromised patients were the prevalence of genes for G adhesins (35% vs. 65%) and expression of MR adhesins (32% vs. 55%). It is concluded that there is a lower prevalence of G adhesins and MR adhesins in Escherichia coli strains from immunocompromised patients than non-immunocompromised patients, suggesting that less virulent Escherichia coli strains may cause urinary tract infections more frequently in renal disease patients and other immunocompromised patients. Moreover, the spectrum of urinary pathogens other than Escherichia coli is similar in both immunocompromised patient groups investigated.

Life-threatening Mycoplasma hominis mediastinitis.

Mycoplasma hominis infections are easily missed because conventional methods for bacterial detection may fail. Here, 8 cases of septic mediastinitis due to M. hominis are reported and reviewed in the context of previously reported cases of mediastinitis, sternum wound infection, pleuritis, or pericarditis caused by M. hominis. All 8 patients had a predisposing initial condition related to poor cardiorespiratory function, aspiration, or complications related to coronary artery surgery or other thoracic surgeries. Mediastinitis was associated with purulent pleural effusion and acute septic symptoms requiring inotropic medication and ventilatory support. Later, the patients had a tendency for indolent chronic courses with pleuritis, pericarditis, or open sternal wounds that lasted for several months. M. hominis infections may also present as mild sternum wound infection or as chronic local pericarditis or pleuritis without septic mediastinitis. Treatment includes surgical drainage and debridement. Antibiotics effective against M. hominis should be considered when treating mediastinitis of unknown etiology.

Occurrence of HLA-B27 tissue antigen in patients with purulent arthritis caused by Staphylococcus aureus or beta-haemolytic streptococci.

The HLA-B27 tissue antigen is associated with reactive arthritis caused by different bacterial infections but its occurrence in purulent arthritis has not been studied earlier. We analysed the frequency of HLA-B27 in patients with culture proven purulent arthritis caused by Staphylococcus aureus or beta-haemolytic streptococci. The study included 41 patients treated during the years 1979-96 (15 female and 26 male) with a mean age of 52 years (range 16-80 years). HLA-B27 was found in 24% (9/37) of the tested patients compared with 14% in the healthy Finnish population, but the difference was not statistically significant (P < 0.50). No statistical difference in disease activity according to febrile days or duration of the disease could be found between HLA-B27 positive and negative patients. We conclude that HLA-B27 is not a risk factor for purulent arthritis, and when present it has no significant modifying effect on the clinical picture of purulent arthritis.

Long-term treatment of ulcerative colitis with ciprofloxacin: a prospective, double-blind, placebo-controlled study.

BACKGROUND & AIMS: Although bacterial bowel flora may be one of the contributing factors in the pathogenesis of chronic mucosal inflammation, antibiotic treatment has no established role in ulcerative colitis. The aim of the study was to evaluate the role of ciprofloxacin in the induction and maintenance of remission in ulcerative colitis in patients responding poorly to conventional therapy with steroids and mesalamine. METHODS: Ciprofloxacin (n = 38; 500-750 mg twice a day) or placebo (n = 45) was administered for 6 months in a double-blind, randomized study with a high but decreasing dose of prednisone and maintenance treatment with mesalamine including follow-up for the next 6 months. Clinical assessment and colonoscopic evaluation were performed at 0, 3, 6, and 12 months. Treatment failure, the primary end point, was defined as both symptomatic and endoscopic failure to respond. RESULTS: During the first 6 months, the treatment-failure rate was 21% in the ciprofloxacin-treated group and 44% in the placebo group (P = 0.02). Endoscopic and histological findings were used as secondary end points and showed better results in the ciprofloxacin group at 3 months but not at 6 months. CONCLUSIONS: Addition of a 6-month ciprofloxacin treatment for ulcerative colitis improved the results of conventional therapy with mesalamine and prednisone.

Hepatosplenic candidiasis in patients with acute leukemia: incidence and prognostic implications.

We studied the incidence among, risk factors for, and survival of adult patients with acute leukemia and hepatosplenic candidiasis during the period 1980 to 1993. Of 562 adult patients with acute leukemia, 38 (6.8%) had hepatosplenic candidiasis. The incidence of infection increased fivefold during the study period. The incidence was higher among patients with acute lymphatic leukemia (11.3%) than among those with acute myeloid leukemia (5.1%) (P = .01). The median survival was 9.5 months, and by the end of follow-up, 74% of patients had died. Patients whose leukemia was in remission before the last cytotoxic treatment preceding hepatosplenic candidiasis survived longer than did patients with newly diagnosed or refractory or relapsed leukemia (P = .0065). Eleven patients died within 3 months after the diagnosis of the infection: 7 of 16 with newly diagnosed leukemia, 4 of 10 with refractory or relapsed leukemia, and 0 of 12 with leukemia in remission (P = .028). In all of the patients who died within 3 months, infection was found at autopsy. In conclusion, the incidence of hepatosplenic candidiasis has significantly increased since 1980, and the outcome for patients with this infection is related to the stage of leukemia.

Prognostic factors associated with improved outcome of Escherichia coli bacteremia in a Finnish university hospital.

All cases of bacteremia caused solely by Escherichia coli in 1977-1979, 1987-1989, and 1993-1994 in a Finnish university hospital were reviewed retrospectively to determine the clinical manifestations, the outcome, and the prognostic factors. In 332 episodes, mortality during the month after the first positive blood culture was 17%. This figure diminished during the study period from 23% in the 1970s to 9% in the 1990s (p = 0.028). Mortality was lowest among patients treated with a combination of antibiotics, 7% versus 18% among those treated otherwise (p = 0.034). The use of acetaminophen increased during the study period from 18 to 55%. Mortality among patients who received acetaminophen within a period < 24 h to 48 h of the first positive blood culture was 10% versus 22% among others (p = 0.002). Logistic regression analysis showed six factors predictive of a fatal outcome: pneumonia, no known focus, shock, CNS disorder, thromboembolism, and rapidly fatal underlying disease. Appropriate antibiotic therapy predicted survival. In the analysis, replacement of appropriate antibiotic therapy by acetaminophen revealed that this drug was significantly associated with survival.

A clinical study of beta-haemolytic groups A, B, C and G streptococcal bacteremia in adults over an 8-year period.

All of the 88 episodes of beta-haemolytic streptococcal bacteremia (2.9% of all bacteremias) in adult patients during the years 1987-94 in a university hospital were reviewed. 38 bacteremias (43%) were caused by group A, 24 (27%) by group B, 3 (4%) by group C, and 23 (26%) by group G beta-haemolytic streptococcal. There was a statistically significant increase in group A and decrease in group C and G bacteremias (p < 0.02) compared to an earlier 8-year period in the same hospital, although the total number of streptococcal bacteremias remained the same. The most common T types of group A streptococcal strains were T11 (26%), T28 (14%), T6 and T1 (11% each), and T12 (8%). Cardiovascular disease, skin lesions, malignancy, and alcohol abuse were the most common underlying conditions. The most usual types of infection were skin (47%) and respiratory tract infections (23%). The overall mortality was 16%. It was highest in group A (24%) and lowest in group C (0%), 38% of patients with pneumonia died. All streptococcal strains were sensitive to penicillin, vancomycin, and cephalosporins. 11% of group A and 12% of all the strains had decreased sensitivity to erythromycin, 14 and 38% to tetracycline, and 0 and 2% to clindamycin, respectively.

Magnetic resonance imaging is superior to computed tomography and ultrasonography in imaging infectious liver foci in acute leukaemia.

We conducted a prospective study in order to compare ultrasonography, computed tomography and magnetic resonance imaging in the detection of liver foci in patients with acute leukaemia and clinical suspicion of hepatic candidiasis. 28 adult patients fulfilling set entry criteria after recovery from neutropenia were studied. Lesions in the liver were detected by at least one imaging modality in 21 patients: by ultrasonography in 7 (33% of detected cases), computed tomography in 12 (57%) and by magnetic resonance imaging in 20 patients (95%). Magnetic resonance imaging was significantly more sensitive than ultrasonography (p<0.001) and computed tomography (p<0.02). The difference between computed tomography and ultrasonography was not statistically significant (p=0.1). Invasive procedures performed in 10 patients provided definite proof of candidiasis in 5 patients, and nodes on the liver surface, compatible with yeast infection, were seen during laparoscopy in 3 other patients without proof of fungal infection. We confirm that magnetic resonance imaging is superior to ultrasonography and computed tomography in imaging liver foci in leukaemic patients recovering from neutropenia with persistent non-specific signs of infection or hepatic involvement.

Bacteremia caused by Brevibacterium species in an immunocompromised patient.

A 46-year-old woman suffering from non-Hodgkin's lymphoma was admitted to the hospital because of high fever. Multiple blood cultures revealed an unusual finding, a Brevibacterium species, which was reisolated 16 days later from the tip of her long-term central venous catheter. This case indicates that Brevibacterium species isolated from normally sterile sites should be considered as a potential pathogen, especially in immunocompromised patients.

Capnocytophaga canimorsus septicemia: fifth report of a cat-associated infection and five other cases.

Capnocytophaga canimorsus is a fastidious, slow-growing, gram-negative, rod-shaped bacterium that belongs to the normal oral flora of dogs and cats. Human septicemic infections are associated with a high mortality; most cases occur in immunocompromised patients with a history of dog bite. The fifth case of cat-associated septicemia caused by Capnocytophaga canimorsus is described. The six case reports presented here point out the characteristics reported previously: (a) cats are a source of human infection; (b) alcohol abuse is an important risk factor for the development of septicemic Capnocytophaga canimorsus infection; (c) septicemic infection often manifests with disseminated intravascular consumption coagulopathy or purpura; and (d) some cases of septicemia in humans result from pets that lick skin ulcers.

Chronic diarrhea due to a single strain of Aeromonas caviae.

Over a period of 17 months, Aeromonas caviae was cultured 15 times as the sole enteropathogen from the feces of a man who had developed chronic diarrhea after traveling to Turkey. Determination of rRNA gene restriction patterns confirmed that the seven isolates of Aeromonas caviae studied were identical (hybridization group [HG]4). After therapy with ciprofloxacin for four weeks, the patient was culture negative for the original isolate, and six months later a novel strain of Aeromonas media with a different ribopattern (HG 5A) was isolated from the feces of the patient. The patient responded again, both clinically and bacteriologically, to a four-week course of ciprofloxacin and has remained asymptomatic since then.

Molecular epidemiology of Staphylococcus epidermidis isolates in a hematological unit during a 4-month survey.

In order to study the strain variety, clonal stability and epidemiology of Staphylococcus epidermidis, isolates from all bacterial cultures taken when clinically indicated in 2 wards of the hematological unit of Helsinki University Hospital, during a 4-month period, were characterized by 3 typing methods: antibiogram, plasmid profile and ribotype. A total of 141 distinct S. epidermidis colonies, from 28 blood cultures and 37 cultures from other sources in 32 patients were studied. Plasmid profiles and ribopatterns revealed 47 different strains of which 16 were bacteremic. One of these strains caused bacteremia in 4 different patients over a 3-month period and it was isolated from blood on 7 different sampling occasions. The occurrence of this clone was constant; it was usually found in both of 2 blood culture bottles inoculated (6/7 pairs) and dominated among the 17 distinct S. epidermidis colonies studied from the positive bottles (94% of the total). The clones causing bacteremias in the 2 wards were distinct. These findings indicate that certain clones of S. epidermidis can predominate in hematological wards and that nosocomial transmission of S. epidermidis strains may occur among patients, particularly within the same ward.

Testing of methicillin resistance by in vitro susceptibility and the presence of the mecA gene in clinical Staphylococcus aureus isolates in Finland.

A total of 140 epidemiologically unrelated Staphylococcus aureus strains collected in Finland between 1983 and 1994 were sent to the reference laboratory with verified or suspected methicillin resistance. These strains and 37 S. aureus strains previously identified as methicillin-susceptible were retested using 5 different susceptibility test methods including agar screening, disc diffusion, growth around methicillin (25 micrograms) test strips and minimal inhibitory concentration (MIC) determinations by an agar dilution method and E-test. The isolates were also analyzed for the presence of the mecA gene by the polymerase chain reaction (PCR). Based on in vitro susceptibility, 69 strains were identified as methicillin-resistant and were positive for the mecA gene in PCR, while 84 strains were methicillin-susceptible and negative for this gene. Susceptibility testing gave conflicting results for 24 (14%) strains. When the tests were repeated in triplicate for each isolate, discrepant results were still achieved with 18 of the 24 strains in at least 2 different tests. Thus, based on in vitro susceptibility, these strains could not be definitely classified as resistant or susceptible to methicillin. Yet 7 of them were positive for the mecA gene as an indication of genetic resistance to methicillin. Corroborating earlier studies, these results illustrate the difficulty of detecting methicillin resistance/susceptibility based only on susceptibility testing and underscore the importance of confirming methicillin resistance in S. aureus in specialized laboratories.

Enteric Plesiomonas shigelloides infections in Finnish patients.

Plesiomonas shigelloides was isolated from 20/13,027 stool samples submitted for culture to the Department of Bacteriology and Immunology, University of Helsinki, in 1990. All except 2/20 Plesiomonas-positive patients had diarrhea; 13 patients had acute onset of illness after foreign travel and 5 patients had chronic diarrhea with symptoms lasting > or = 2 months. Travel destinations were outside Europe in most cases. In 12 cases Plesiomonas was isolated in pure culture and in 8 cases together with other enteropathogens. All isolates were susceptible to ciprofloxacin, doxycycline, trimethoprim and sulfamethoxazole, gentamicin, cephalexin, cefuroxime, ceftriaxone and cefixime.

Arcanobacterium haemolyticum and streptococcal pharyngitis in army conscripts.

Arcanobacterium haemolyticum was found in 1.4% and beta-haemolytic streptococci in 23% of throat cultures from army conscripts with sore throat (n = 498). 38% of the beta-haemolytic streptococci were of group A. Patients culture-positive for A. haemolyticum or beta-haemolytic streptococci had pharyngeal exudate, cervical lymphadenopathy and ear ache significantly more often--but cough less often--than culture-negative patients. The pharyngeal colonization rate of healthy conscripts (n = 232) by A. haemolyticum was 0.4% and by beta-haemolytic streptococci, 6.5%.

Role of aeromonas isolated from feces of Finnish patients.

Aeromonas species were isolated from 249/13,027 (1.9%) stool samples submitted to the Dept. of Bacteriology and Immunology, University of Helsinki, during 1 year, to be cultured for bacterial enteropathogens. Aeromonas was the third most common enteropathogen isolated, after campylobacter (3.6%) and salmonella (3.3%). Isolates and clinical information from 234 Aeromonas patients were available for further study. A. caviae (41%), A. hydrophila (27%), and A. veronii biovar sobria (22%) were the most frequent isolates. In 15% of the patients, other enteropathogens were found along with aeromonas. Only 2% of all aeromonas-positive patients were found to be asymptomatic, whereas no aeromonas isolates were detected in the stools of 343 asymptomatic individuals. Almost all (96%) patients with aeromonas in their feces had gastroenteritis. Patients infected with A. veronii biovar sobria had a shorter illness course and had more often travelled abroad. In conclusion, Aeromonas spp. were found to be a potential cause of diarrhea in Finnish patients.

Association of Stomatococcus mucilaginosus with cholangitis.

The first case of cholangitis in which Stomatococcus mucilaginosus was cultured from bile is reported. A 64-year-old male became icteric and was shown to have gallstones in the gallbladder and a common bile duct stone which was removed endoscopically. As the patient remained icteric for a month thereafter the gallbladder with stones was removed. No common bile duct stone was shown by cholangiography perioperatively. The liver biopsy revealed cholangitis and Stomatococcus mucilaginosus was grown from the bile. The patient was cured by cholecystectomy without any antimicrobial therapy.

Hepatosplenic yeast infection in patients with acute leukemia: a diagnostic problem.

The occurrence of hepatosplenic candidiasis following prolonged neutropenic periods has emerged as a major problem for patients with leukemia. In order to evaluate the diagnostic value of various available procedures, we analyzed our findings regarding 26 leukemic patients with hepatosplenic candidiasis. A significantly increased level (> 50 mg/L) of serum C-reactive protein (S-CRP) was significantly more common than a daily fever (for which the mean temperature peak was > 37.5 degrees C) or raised levels of liver enzymes (serum alanine transferase, aspartate transferase, or alkaline phosphatase). Focal changes in the liver, spleen, or kidneys were detected in > 90% of the patients examined by computed tomography (CT) but in < 50% of those examined by ultrasonography. Seventeen diagnoses were based on the findings from microscopy of samples obtained invasively, whereas a positive fungal culture was the basis of the diagnosis for only five patients. In conclusion, monitoring the S-CRP level after a patient's recovery from neutropenia is useful in that its elevation is cause for early suspicion of hepatosplenic candidiasis. In detection of the hepatosplenic foci, CT is superior to ultrasonography. For establishing the specific diagnosis, aggressive collection of samples for microscopy is essential.