Legionella pneumonia in transplant recipients: a cluster of cases of eight years' duration

Infection with Legionella is often encountered in immunosuppressed patients, especially in recipients of renal allografts. From January 1985 until April 1993 14 cases of nosocomial legionella pneumonia were diagnosed (four by culture, 10 by serological methods) on the surgical transplantation unit of Innsbruck University Hospital. All isolates from patients and from the building's hot water were found to be Legionella pneumophila serogroup 1. They were indistinguishable from each other by monoclonal antibody subtyping and restriction fragment length polymorphism pattern and thus indicated a series of infections originating from the same source during a period of more than 8 years. Repeated efforts to control Legionella by raising the temperature in the hot water lines failed to bring permanent success. Replacing the central hot water supply with small electric water heaters installed in the patient rooms on the transplant ward now seems to have reduced the incidence of legionellosis on this unit. However, further infections occurring in transplant patients in other surgical departments in the same building indicate that a major renovation of the whole surgical building's hot water system is necessary.

[Occurrence of swimmer's itch in Tyrol]

Cercariae from trematodes of birds are capable of penetrating human skin causing a dermatitis, called swimmer's itch. In 1992, after a hot dry summer there was a marked increase in the incidence of cercarial dermatitis in Austria. Although the increased incidence of this complaint can be quite worrisome for the population, the occurrence of swimmer's itch can, in fact, generally be seen as harmless. Cercarial dermatitis responds well to treatment with topical antihistamines or cortisone; even without medication the skin rash heals within 2-3 weeks. The effectiveness of various preventive measures (such as protective sun cream or patting the skin dry) is controversial. The use of molluscicides is definitely contraindicated due to the inoffensive nature of this dermatitis. While it is usually easy to recognize swimmer's itch when there is an increased incidence, the diagnosis is often missed when it occurs sporadically, due to its unspecific characteristics.

Molecular epidemiology of tuberculosis in Austria

The incidence of pulmonary tuberculosis among newspaper vendors, tram operators, and other exposed groups leads to repeated discussions about the importance of single cases for the spread of tuberculous infection. We subjected 36 strains of Mycobacterium tuberculosis, isolated in 1992 from 31 patients, to restriction fragment length polymorphism analysis using PvuII and an insertion element 986 probe. Only two isolates obtained from a married couple showed the same DNA fingerprinting pattern, all the other strains had unique and clearly distinguishable banding patterns. Our investigation revealed no dominating strains except in the case of one married couple, where the chain of infection was obvious (the wife being diagnosed during the course of testing of her alcoholic and tuberculous husband's contacts). The main emphasis in the fight against tuberculosis still rests on securing the availability of diagnostic and therapeutic means for all patients with tuberculosis. The importance of single infected source cases for the spread of tuberculosis should not be overestimated.

In vitro susceptibility of Candida albicans, Austria 1992

A total of 38 isolates of Candida albicans were collected from clinical specimens and tested for minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs) of amphotericin B, flucytosine and fluconazole. For amphotericin B and flucytosine all patients had isolates with MICs < or = 2 micrograms ml-1 and < or = 8 micrograms ml-1 respectively. For fluconazole all but two isolates had MICs < or = 16 micrograms ml-1. In vitro susceptibility testing remains problematic since standardized methods have not been established and the susceptibility and resistance ranges of MIC/MFC values still have to be defined in relation to in vivo data. Nevertheless, these results indicate that topical application of amphotericin B (more than 1 kg of amphotericin B per year at an intensive care unit performing selective digestive tract decontamination on certain trauma patients) had no major impact on the resistance patterns of C. albicans. In contrast, in this study both fluconazole-resistant isolates were from AIDS patients who were known to have received fluconazole therapy. Treatment with fluconazole--quite common in patients with AIDS--may produce resistant fungal isolates.

In vitro experiments on catheter-related infections due to gram-negative rods

Although many complications may arise with the use of central venous catheters, catheter-related bacteremia is considered to be the most serious complication. Microflora on the patient's skin (coagulase-negative staphylococci, Staphylococcus aureus) is thought to represent the major source of microorganisms causing catheter-related infections. Gram-negative rods are increasingly observed as causative agents. We therefore performed an in vitro study to elucidate the pathogenesis of polymer-associated infections caused by enterobacteriaceae and nonfermenters and to study the resistance of polymer surface-grown gram-negative rods against antibiotics. Using a modification of the semiquantitative method for culturing vascular cannulas on solid media described by Maki et al., we studied the adherence of various gram-negative rods to 1-cm segments of silastic catheters, a material used for Port-A-Cath-systems. Organisms were obtained from the American Type Culture Collection (Escherichia coli, Klebsiella pneumoniae, Serratia marcescens, Pseudomonas aeruginosa, Enterobacter cloacae). All organisms but Klebsiella showed extensive irreversible adherence. Production of an extracellular slime substance was observed only with antimicrobially treated Pseudomonas. After 'infection', the silastic catheter segments were treated with various antimicrobial agents. The following antibiotics were used either individually or in combination: cefotaxime, ciprofloxacin, imipenem, fosfomycin and gentamicin. Despite the fact that the antibiotic concentrations used were many times greater than the respective MICs of the various antibiotics, none of the antibiotics tested succeeded in eliminating the organisms. E. coli was found to be the most susceptible organism. These in vitro data substantiate our clinical impression that it is hardly possible to successfully eliminate the colonization of central venous catheters with gram-negative rods by using the antimicrobial agents employed here.

[Effect of Listeria on contractibility of human uterine muscle]

In Austria the prevalence of listeriosis is 2.6 cases per million inhabitants yearly, hence rather rarely the cause of spontaneous abortion or premature birth. On the other hand, Listeria monocytogenes is found in 1% of the asymptomatic population as a component of stool flora. Since the cause of premature labour contractions remains unclear in about half of all cases, we examined 29 listeria strains for their ability to cause myometrial contraction by direct contact using an in-vitro uterine strip-model. Seven of nine L. monocytogenes strains were able to cause contractions; contractions were not inducible by an nonhaemolytic mutane (SLCC 53, avirulent) nor by a rough strain (SLCC 5779, only slightly virulent). Three of six L. ivanovii isolates also exhibited the ability to induce contractions. None of the apathogenic species (L. innocua, L. seeligeri, L. welshimeri, L. grayi and L. murrayi) was capable of activating contractions in our in-vitro model. Only L. monocytogenes and L. ivanovii cause conjunctivitis after being dropped in rabbit's eyes (positive Anton Test). The influence of listeria on uterine activity as found in our in-vitro model thus correlates with the classical pathogenicity test. We consider these in-vitro results as an additional argument to oppose the presence of L. monocytogenes in ready-to-eat foods.

Vero cytotoxin-producing Escherichia coli O157 infections in Austria

To determine the prevalence of Vero cytotoxin-producing Escherichia coli (VTEC) serotype O157 associated diarrhea in the Austrian patient population, we surveyed all stool specimens of liquid consistency submitted to the Federal Public Health Laboratory (FPHL) in Innsbruck for 2 years for this organism. This laboratory serves a population of approximately 1 Million people. Of 5,265 stool specimens, 7 yielded O157 VTEC. Five isolates of E. coli O157 phage type 32, VT2 were cultured from specimens received during a three day period from residents in the county of Schwaz. During the investigation of this "outbreak" E. coli O157 strains were also isolated from two household contacts. Only 1 out of 8 persons with E. coli O157 diarrhea had bloody stools, although 5 of 7 tested specimens (= 71%) also yielded Campylobacter jejuni. None of our patients received antimicrobial therapy directed against E. coli O157 (one child had josamycin). There were no fatalities and no cases of hemolytic uremic syndrome (follow up period: 6 months). Consumption of hamburger, roast beef, and unpasteurized milk was not confirmed in this study. In Austria, no O157 VTEC strain was isolated till June 1992, although at the FPHL in Innsbruck stool specimens of liquid consistency were cultured for this organism since January 1991.

Listeria monocytogenes infection in prosthetic joints

Listeria monocytogenes is increasingly recognised as a cause of prosthetic joint infection. These infections tend to be more insidious and indolent in contrast to similar infections with Staphylococcus aureus. They can occur in patients who are immunocompromised due to malignancy or other illness or in nonimmunocompromised elderly patients. Listeria infections should not be treated with cephalosporins and prolonged antimicrobial treatment is generally advised for prosthetic joint infections. We noted a high affinity of L. monocytogenes for foreign bodies. Three of twenty-seven cases 11%) of listeriosis under the period of investigation were associated with foreign bodies (hip prosthesis, knee prosthesis and arterial graft).

In vitro and in vivo effect of antibiotics on catheters colonized by staphylococci

An in vitro model was used to study whether and how catheter infections can be cured. Silastic catheters were "infected" with Staphylococcus aureus ATCC 25923 and Staphylococcus epidermidis KH11 and V2; these "infections" were then treated with 24, 48 and 96 h continuous infusions of various antimicrobial agents administered both as monotherapy and in combination. The Staphylococcus aureus strain was considerably more difficult to eliminate from catheters than were the Staphylococcus epidermidis strains. This experience gained in the laboratory was then applied in vivo to 16 episodes of catheter sepsis in seven children. Treatment for at least six days with imipenem/cilastatin combined with fosfomycin or an aminoglycoside successfully eliminated the pathogens isolated from 11 of the 16 episodes of infection. The broad-spectrum combination was chosen because it could not be assumed that individual pathogens would be sensitive to a single substance. Nine of the infected catheters could be retained in the patients. This experience suggests that it may be possible to successfully eliminate the colonization of central venous catheters by coagulase-negative staphylococci using the antimicrobial agents employed here.

[Calcofluor-white staining in the identification of Pneumocystis carinii]

Calcofluor white stain is widely used as a fluorescent stain in mycology. Recently, it was found that by calcofluor white staining Pneumocystis carinii cysts exert a highly characteristic staining pattern. We retested fifteen clinical specimens which were known to be positive for Pneumocystis carinii (diagnosis made by a methenamine silver stain). Calcofluor white stain proved to be a simple, rapid, and inexpensive method for detecting Pneumocystis carinii in clinical specimens.

Campylobacter fetus subspecies fetus infection

During a six-year period five patients with Campylobacter fetus subspecies fetus infections were seen at the Mayo Clinic in Rochester, Minnesota. Bacteremia was observed in two patients, one presenting with aortic valve endocarditis and the other with abdominal atherosclerotic aortic aneurysm. C. fetus subsp. fetus was isolated from tibial tissue of a patient with osteomyelitis. Diarrhea was the main complaint of two further patients, and was also mentioned by the patient with the aortic aneurysm. Despite the use of incubation conditions and selective media geared to detect only Campylobacter jejuni, C. fetus subsp. fetus was isolated from stool specimens of the two patients with gastrointestinal symptoms. The fact that three of five C. fetus subsp. fetus infections observed in this study were associated with intestinal symptoms further supports the importance of the gastrointestinal tract in the pathogenesis of C. fetus subsp. fetus infections.

Serodiagnosis of echinococcosis: evaluation of two reference laboratories

Two reference laboratories (CDC, Atlanta, and Institute of Hygiene, Vienna) were evaluated for their ability to diagnose echinococcosis from single serum-specimens by serological assays. Out of 18 specimens, both laboratories correctly identified the 12 sera from patients with echinococcosis. Each laboratory was able to give the species diagnosis for 11 of 12 cases. The CDC abstained from giving a final species-diagnosis for a serum from a patient with alveolar echinococcosis, the Institute of Hygiene similarly, for a case of cystic echinococcosis. Our findings reveal the considerable potential of today's serological methods for primary diagnosis of infections with Echinococcus granulosus and Echinococcus multilocularis.

High risk of developing toxoplasmic encephalitis in AIDS patients seropositive to Toxoplasma gondii

We studied 41 AIDS patients in the Austrian Tyrol with respect to toxoplasma antibody titers and the presence of CNS toxoplasmosis. In no patient had primary Pneumocystis carinii pneumonia (PcP) prophylaxis with either trimethoprim/sulfamethoxazole or pyrimethamine/sulfadoxine been applied; the degree to which CNS toxoplasmosis is influenced by this kind of PcP chemoprophylaxis, widely used elsewhere, is still unclear. In this study 47.4% of toxoplasma-seropositive patients developed CNS toxoplasmosis, compared to the previously estimated risk of 12%-28% for developing CNS involvement in such patients. In view of the high risk of toxoplasma-seropositive patients with AIDS, increased efforts in developing a well-tolerated chemoprophylaxis to combat CNS toxoplasmosis are required.

Spectrum of in vitro antifungal activity of ditiocarb sodium

The immunomodulator ditiocarb sodium (sodium diethyldithiocarbamate, DTC, CAS 148-18-5) is finding increasing use in treating AIDS-patients. Using a macro broth dilution method the minimal inhibitory concentrations and minimal fungicidal concentrations of DTC were studied for 76 fungal strains (54 species) and a broad spectrum of direct antifungal activity was found. All 6 Candida albicans strains tested were inhibited by 1.2 micrograms DTC/ml, a concentration achievable by i.v. administration of DTC in doses as presently used for immunomodulation. All strains of Cryptococcus were inhibited by DTC in concentrations of 2.5 micrograms/ml. In combination with amphotericin B, DTC showed a synergistic mode of action for 6 out of 7 Cryptococcus neoformans strains (checkerboard technique). As far as the direct antifungal activity of DTC was tested (11 strains, 5 species), the combination with amphotericin B or flucytosine showed no antagonistic mode of action. The augmentation of host defences by the immunomodulating agent DTC could become an adjunct to conventional therapy in immunocompromised patients with systemic fungal infections.

Campylobacter bacteremia: clinical experience with three different blood culture systems at Mayo Clinic 1984-1990

The efficiency of three commercially available blood culture systems for isolating Campylobacter sp. was investigated. Thirteen of 189,688 blood cultures from patients seen at the Mayo Clinic from 1984 through 1990 were positive for Campylobacter sp. Eleven out of 13 blood cultures positive for Campylobacter sp. were part of a complete three bottle set of cultures (Isolator from Du Pont, Roche Septi-Chek from Hoffman-La Roche, and non-vented Tryptic Soy Broth from Difco), none of them providing a specific microaerophilic mileu. The aerobic Roche Septi-Chek seems to be more efficient for the detection of Campylobacter sp. in blood cultures than either the anaerobic Tryptic Soy Broth (Difco) or the Isolator (Du Pont) using the incubator condition of 5% CO2.

An investigation of nosocomial infection with Corynebacterium jeikeium in surgical patients using a ribosomal RNA gene probe

Twelve strains of multi-resistant Corynebacterium jeikeium isolated during a one year period in a surgical unit in Innsbruck were analyzed with regard to their plasmid content, antibiotic susceptibility, and the use of ribosomal ribonucleic acid (rRNA) to probe restriction fragment length polymorphism (RFLP). Plasmids were detected in five of the strains. Southern blotting of genomic DNA digested with HindIII or PvuII and hybridized with a biotin-labelled cDNA probe derived from total rRNA revealed characteristic banding patterns. Seven of the 12 strains showed similar RFLP profiles, consistent with them being related epidemiologically. The minor changes in RFLP profiles observed in these seven strains suggest that Corynebacterium jeikeium may be subject to genetic drift over a relatively short time span. Strains from other sources, included for comparison, differed markedly from those from Innsbruck. Patterns of antibiotic susceptibility which appeared not to be plasmid encoded, correlated broadly with RFLP profiles. This study suggests that strains of Corynebacterium jeikeium may be transferred between hospital patients.

[Lyophilized cartilage--an antibiotic carrier]

Human lyophilized bruised costal cartilage was tested in vitro for its ability to act as a carrier medium for antibiotics. A remarkable capacity of accumulating streptomycin, gentamicin, tobramycin, vancomycin and ciprofloxacin was observed; whereas beta-lactum antibiotics and fosfomycin were released at a high rate. This release pattern was not influenced by the sterilization procedure, but rather by the size of the cartilage granula. Lyophilized cartilage--rehydrated in antibiotic-solutions--be helpful adjunct in the surgical management of osseous infections.

[Acute tonsillitis: clinical symptoms; bacteriologic culture and rapid test as deciding criteria for the use of antibiotics]

In order to prevent late sequelae from an untreated streptococcal pharyngitis all patients with streptococcal tonsillitis/pharyngitis have to be treated with antibiotics, preferably penicillin. A correct diagnosis by clinical criteria is only achievable in 72% of patients with streptococcal pharyngitis. Additional criteria such as diagnosis by culture are, therefore, mandatory. Time is a major disadvantage of traditional culture methods. Slide agglutination tests show an acceptable sensitivity of 92% and a specificity of 93%. Due to the possibility of false negative test results, with consequent withholding of adequate antimicrobial chemotherapy, these test results should be used only as a valuable guide. Decision to administer an antibiotic should still be based on clinical criteria.