Impact of graft colonization with gram-negative bacteria after lung transplantation on the development of bronchiolitis obliterans syndrome in recipients with cystic fibrosis.

Bronchiolitis obliterans syndrome (BOS) represents the leading cause of late mortality after lung transplantation (LTx). Cystic fibrosis (CF) patients frequently show airway colonization with gram-negative bacteria (GNB) both before and after LTx. Graft colonization with GNB and its relevance towards BOS development were investigated in a CF population after LTx. Adult CF patients receiving LTx and surviving at least 6 months were included in this prospective observational study between 1/1/2002 and 30/6/2006 in a single center and followed until 31/3/2007. Pre- and post-LTx respiratory culture samples were compared for the presence of identical GNB. BOS-free survival was compared in colonized and non-colonized patients. Fifty-nine adult CF patients with a median age at LTx of 25.5 (18-49) years were included and had a median follow-up of 966 (128-1889) days. Seven patients (15%) demonstrated immediate eradication of GNB in lower respiratory tract samples. A further 18 patients (34%) demonstrated transient colonization. Thirty-four recipients had further positive samples after LTx. Eighteen patients (31%) developed BOS >or=stage 1, 508 (114-1167) days after LTx. Freedom of graft colonization with pseudomonads was independently associated with less frequent development of BOS (p=0.006). Persistent graft colonization with pseudomonads increases the prevalence of BOS after LTx in CF patients. A significant proportion of post-LTx CF patients demonstrates subsequent GNB eradication during later follow-up and this may have a protective role against development of BOS. Strategies to eradicate airway colonization or reduce bacterial load may prevent BOS in CF patients after LTx.

Impact of bacterial and fungal donor organ contamination in lung, heart-lung, heart and liver transplantation.

We investigated to which extent bacterial and fungal donor organ contamination (DOC) caused posttransplant nosocomial infections (NI) in solid organ transplant (Tx) recipients. Between January 2002 to December 2003 (lung and heart Tx) and October 2003 to September 2004 (liver Tx), NIs were determined according to modified CDC criteria for NIs for all transplantations performed at Hannover Medical School. Organisms of the same species cultured from donor organs and infected transplantees were genotyped if available. Out of 282 solid organ recipients (140 lung-Tx, 16 heart-lung-Tx, 51 heart-Tx, 75 liver-Tx), 150 recipients (53.2%) received contaminated donor organs. Incidences of NIs were 33.7% in lung, 68.8% in heart-lung, 21.6% in heart, and 28% in liver recipients. In 11 out of 282 transplantees (3.9%, CI (95%) 2.0-6.9%) organisms of NIs and of contamination of the donor organ were of the same species. Even if assuming five missing pairs of organisms as genetically identical, incidences of DOC-related posttransplant infections were only between 1.3% (CI(95%) 0.0; 7.2) in liver-Tx and 18.8% (CI(95%) 4; 45.6) in heart-lung Tx, and DOC related mortality was 0.4% (CI(95%) 0.0;1.9). Despite high DOC rates, posttransplant infections due to DOC were rare under the condition of adequate preoperative antibiotic prophylaxis and aseptic organ retrievement.

Evaluation of the E test for the assessment of synergy of antibiotic combinations against multiresistant Pseudomonas aeruginosa isolates from cystic fibrosis patients.

The determination of synergistic effects of antimicrobial drug combinations can lead to improved therapeutic options in the antibiotic treatment of cystic fibrosis patients who are chronically infected with multiresistant Pseudomonas aeruginosa isolates. The aim of this study was to evaluate the performance of the E test versus the standard agar dilution checkerboard susceptibility test in the assessment of synergy and, in addition, to determine the activity of two antimicrobial combinations against 163 multiresistant P. aeruginosa isolates from cystic fibrosis patients. The agreement between the checkerboard method and the E test was excellent (>90%) for nonmucoid as well as mucoid isolates from cystic fibrosis patients. The rate of synergy was higher for the antibiotic combination of ceftazidime and tobramycin (28.8% of the cystic fibrosis strains) than for the combination of meropenem and tobramycin (19.0%). However, the probability of synergy for the second antibiotic combination increased significantly when the synergy of the first antibiotic combination had already been demonstrated (Fischer's exact test, p=0.049). The results show that the E test is a valuable and practical method for routine microbiological diagnostics and can aid in the selection of improved antibiotic options in the treatment of cystic fibrosis patients chronically infected with P. aeruginosa.

[Surveillance of invasive mold infections in lung transplant recipients: effect of antimycotic prophylaxis with itraconazole and voriconazole]. / Surveillance invasiver Fadenpilzmykosen in lungentransplantierten Patienten: Effekt antimykotischer Prophylaxe mit Itraconazol und Voriconazol.

Between January 2002 and December 2003 all 157 patients (pts) that underwent lung transplantation (LTx) at our institution were prospectively screened for invasive aspergillosis (IA) during their perioperative hospital stay. Patients were regarded as IA positive, if they met the EORTC criteria for 'probable' or 'proven' IA. Records of pts were screened retrospectively for antimycotic prophylaxis. Eight of the 157 pts developed 'probable' or 'proven' IA (5.1%) within 17 +/- 10 days after LTx. This was associated with a 14-fold increased mortality compared with all pts without aspergillosis (P < 0.01, OR 13.8, CI(95%) 2.5-82). Preoperative colonization with Aspergillus was a significant risk factor for IA (P < 0.001, OR 21.9, CI(95%) 4.9-97). We switched our prophylactic strategies to the primary administration of voriconazole in high risk pts (pre-LTx colonization) starting in December 2002. Six pts (6%) of 101 pts receiving itraconazole for antimycotic prophylaxis beginning at postoperative day (POD) one developed IA, of which three pts showed cerebral aspergillosis. One pt (5%) of 18 pts receiving voriconazole prophylaxis developed IA, while 10 pts showed pretransplant colonization with Aspergillus species. Thirty-eight pts received itraconazole prophylaxis at a later time point (>POD 14). By switching our prophylactic strategy to the use of voriconazole in high risk pts, we have decreased the incidence of IA from 8% (six of 75) in 2002 to 2% (two of 82) in 2003. This study shows a high incidence of IA during the very early postoperative course after LTx of 5%. This is associated with a significantly increased risk for mortality. Voriconazole prophylaxis appears to be superior to itraconazole, especially in high risk pts with pretransplant Aspergillus colonization.

Comparison of the Micronaut Merlin automated broth microtiter system with the standard agar dilution method for antimicrobial susceptibility testing of mucoid and nonmucoid Pseudomonas aeruginosa isolates from cystic fibrosis patients.

The aim of this study was to compare a commercially available automated broth microdilution system (Merlin; Micronaut, Germany) with the standard agar dilution method for susceptibility testing of pulmonary isolates from cystic fibrosis patients. Accurate susceptibility testing of bacterial isolates from cystic fibrosis patients is known to pose problems. Although commercially available automated test systems could facilitate susceptibility testing of such isolates in routine diagnostics, these systems have not been recommended thus far. However, a pilot study recently indicated that the Merlin system, which is based on an endpoint measurement rather than on growth curves, might be applicable in the susceptibility testing of isolates from cystic fibrosis patients. In the present study, the Merlin system was further evaluated using an extended panel of nonmucoid and mucoid Pseudomonas aeruginosa isolates. The results showed that the MICs obtained with the Merlin system tended to be lower than those obtained with the agar dilution method, a finding that became increasingly apparent when mucoid Pseudomonas aeruginosa strains were tested. The correlation coefficients (r values) of the MIC results for all strains tested were between 0.6 and 0.8 for five of the seven antimicrobial agents, with r values exceeding 0.8 for only meropenem and ciprofloxacin. However, since the overall rate of serious discrepancies was within an acceptable range, the Merlin system appears to be applicable for routine clinical use in susceptibility testing of P. aeruginosa isolates from cystic fibrosis patients.

Two case reports: fatal Absidia corymbifera pulmonary tract infection in the first postoperative phase of a lung transplant patient receiving voriconazole prophylaxis, and transient bronchial Absidia corymbifera colonization in a lung transplant patient.

Absidia corymbifera is a rare cause of pulmonary tract infection. There exist only 5 case reports predominantly diagnosed in bone marrow transplant patients. Lung transplant patients are at high risk for invasive fungal infections. Due to A. corymbifera as pathogen, known to be voriconazole resistant, a fatal invasive pulmonary mycosis occurred. In the present case voriconazole prophylaxis failed. A second patient showed a transient colonization of the bronchi. To prevent airborne transmitted invasive pulmonary mycosis in the first postoperative period of lung transplantation the patient should be situated in a room ventilated by HEPA-filtered air. The specific treatment should start very early when first suspicion arises. A review of the literature on pulmonary tract infections induced by Absidia corymbifera is provided.

Evaluation of the Merlin, Micronaut system for automated antimicrobial susceptibility testing of Pseudomonas aeruginosa and Burkholderia species isolated from cystic fibrosis patients.

Since accurate antimicrobial susceptibility testing of bacterial cystic fibrosis isolates is known to be problematic and an optimal in vitro testing method has not yet been evaluated, the study presented here was conducted to compare the performance of the reference agar dilution method and broth microdilution with a commercially available automated susceptibility test system (Merlin; Micronaut, Germany). In this pilot study, the susceptibility of 70 clinical strains of Pseudomonas aeruginosa and Burkholderia cepacia-like organisms to nine antimicrobial agents was tested using these methods. Susceptibility results generated by broth microdilution (both automated and according to the National Committee for Clinical Laboratory Standards recommendations) were demonstrated to be of good reproducibility, and they compared favourably to the time- and material-consuming standard agar dilution reference method, especially after a prolonged incubation time (48 h).

Efficacy of a benzalkonium chloride-impregnated central venous catheter to prevent catheter-associated infection in cancer patients.

BACKGROUND: This study was performed to determine the efficacy of a benzalkonium chloride-impregnated central venous catheter (CVC) in preventing catheter-related infection in patients suffering from malignant diseases and undergoing chemotherapy. METHODS: A randomized, prospective clinical trial was carried out to compare the incidence of catheter-related colonization and catheter-related bacteremia using an antiseptic-impregnated CVC (n = 25) with that using a standard triple-lumen CVC (n = 25). RESULTS: All patients were treated with intensive chemotherapy for acute leukemia (n = 28), lymphoma (n = 17) or solid tumors (n = 5). Both study groups presented with similar data in regards to age, insertion site, duration of catheterization and neutropenia period during catheterization, demonstrating a comparable risk for catheter-related colonization. Suspicion of infection led to explantation in 14 versus 15 cases. Catheter-related colonization was proven in 4 cases (16%) and catheter-related bacteremia was observed only once (4%) in both groups. Statistical testing showed no significant differences between the study and control group. CONCLUSIONS: The rate of catheter-related colonization was lower than suspected in this high-risk patient group. The use of benzalkonium chloride-impregnated CVC failed to decrease the incidence of catheter-related colonization and bacteremia in patients with a high risk of infectious complications.

Small-colony variants of Pseudomonas aeruginosa in cystic fibrosis.

In the context of chronic lung infection due to Pseudomonas aeruginosa in cystic fibrosis (CF), attention has been focused on the presence of the most common mucoid phenotype. In this study, the presence of small-colony variants (SCVs) of P. aeruginosa in respiratory tract specimens from patients with CF was investigated, and the clinical conditions predisposing to SCVs were analyzed. P. aeruginosa SCVs were isolated from 33 of 86 P. aeruginosa-positive CF patients over a 2-year period. Fast-growing revertants with larger surface colonies could be isolated from SCV populations. Electron microscopy revealed no significant difference in cell size or morphology. MICs of a broad range of antipseudomonas agents for SCVs were two- to eightfold higher than values for revertants. Recovery of SCVs was correlated with parameters revealing poor lung function and was significantly associated with daily inhalation of tobramycin or colistin.

Epidemiology of chronic Pseudomonas aeruginosa infections in the airways of lung transplant recipients with cystic fibrosis.

BACKGROUND: The source of airway colonisation with Pseudomonas aeruginosa is not well defined in patients with cystic fibrosis after lung transplantation. Using a DNA-based typing system a study was undertaken to investigate whether lung transplant recipients acquired new strains of P aeruginosa or retained those they had before transplantation. METHODS: Seventy four P aeruginosa isolates taken before and after transplantation were analysed from 11 patients with cystic fibrosis who had undergone lung transplantation in the Medical School of Hannover between 1988 and 1994. The genetic relatedness of the 74 P aeruginosa strains was evaluated from macrorestriction fragment pattern similarity. RESULTS: Each of the 11 lung transplant recipients harboured one identical P aeruginosa clone before and after transplantation. The airways of four of the 11 patients were preoperatively colonised by two or three different clones, but six months after transplantation only one clone was detectable. CONCLUSIONS: These results show that there is no change in the P aeruginosa population in the airways of lung transplant recipients before and after transplantation and it is assumed that the chronic drainage of P aeruginosa into the lung allografts is caused by the bacterial reservoir in the paranasal sinuses and the trachea.

Manifestations of Chlamydia induced arthritis in patients with silent versus symptomatic urogenital chlamydial infection.

OBJECTIVES: To evaluate whether Chlamydia-infected patients with and without urogenital symptoms have similar rheumatological manifestations or whether they belong to distinct clinical groups. METHODS: In a university-based study, we examined patients with unexplained arthritis in whom other rheumatic diseases had been excluded for urogenital chlamydial infection, and we investigated the clinical and radiological manifestations of the Chlamydia-positive patients. RESULTS: Sixty of 283 patients (21%) with unexplained arthritis had urogenital chlamydial infection. The infection was asymptomatic in 30%. There was no difference in the pattern of arthritis or immunological and serological characteristics in the patients with and without symptoms of urogenital infection, respectively. CONCLUSION: The pattern of Chlamydia-induced arthritis is similar in patients with or without symptoms of urogenital chlamydial infection. To recognize CIA, it may be helpful to examine patients with unexplained arthritis for Chlamydia even though they do not have symptoms of urogenital infection.

Lentzea gen. nov., a new genus of the order Actinomycetales.

We describe a new genus of mesophilic actinomycetes, for which we propose the name Lentzea. The strains of this genus form abundant aerial hyphae that fragment into rod-shaped elements. Whole-cell hydrolysates contain the meso isomer of diaminopimelic acid and no characteristic sugar (wall chemotype III). The phospholipid pattern type is type PII (phosphatidylethanolamine is the characteristic phospholipid); the major menaquinone is MK-9. The fatty acid profile comprises saturated, unsaturated, and branched-chain fatty acids of the iso and anteiso types in addition to tuberculostearic acid (10Me-C18:0). A 16S ribosomal DNA sequence analysis revealed that the genus Lentzea is phylogenically related to the genera Actinosynnema, Saccharothrix, and Kutzneria. The type species of this genus is Lentzea albidocapillata sp. nov.; the type strain of this species is strain IMMIB D-958 (= DSM 44073).

Genetic determinants of airways' colonisation with Pseudomonas aeruginosa in cystic fibrosis.

Exocrine pancreatic insufficiency and lung infection with Pseudomonas aeruginosa are major features of cystic fibrosis (CF). This monogenic disease is caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. 267 children and adolescents with CF who were regularly seen at the same centre were assessed for an association of the CFTR mutation genotype with exocrine pancreatic function and the age of onset of chronic colonisation with P aeruginosa. The major mutation delta F508 accounted for 74% of CF alleles; 33 further CFTR mutations had been detected on the CF chromosomes of the study population by June, 1992. With the exception of delta F508/R347P compound heterozygotes, patients of the same mutation genotype were either pancreas insufficient (PI) or pancreas sufficient (PS). The age-specific colonisation rates with P aeruginosa were significantly lower in PS than in PI patients. The missense and splice site mutations that are "mild" CF alleles with respect to exocrine pancreatic function were also "low risk" alleles for the acquisition of P aeruginosa. On the other hand, the proportion of P aeruginosa-positive patients increased most rapidly in the PI delta F508 compound heterozygotes who were carrying a termination mutation in the nucleotide binding fold-encoding exons. Pancreatic status and the risk of chronic airways' colonisation with P aeruginosa are predisposed by the CFTR mutation genotype and can be differentiated by the type and location of the mutations in the CFTR gene.

Nosocomial acquisition of Pseudomonas aeruginosa by cystic fibrosis patients.

During a 4-year period, at least 12 of 40 patients with cystic fibrosis (CF) who were newly colonized with Pseudomonas aeruginosa had acquired it at CF recreation camps, clinics, or rehabilitation centers. After introduction of hygienic precautions at the CF clinic, only a single episode of nosocomial transmission of P. aeruginosa was detected at the CF ward during the subsequent 2 years.

Epidemiology and treatment of gastric Campylobacter pylori infection: more questions than answers.

Two-hundred and ten consecutive patients undergoing routine gastroscopy were additionally investigated for evidence of Campylobacter pylori (C.p.). 106 patients were positive in one or more tests: 99.1% using a rapid urease detecting test (CLO-test), 80.2% histology, 78.3% cytology and 60% culture. We found no difference between the CLO-test results from biopsies taken from different parts of the stomach in individual patients. C.p. was found in 100% of patients with significant chronic antral gastritis, 67.7% with gastric ulcers, 65% with duodenal ulcers and in 12.1% of normal individuals. The C.p. infection was apparently eliminated in 50% of cases treated with bismuth subsalicylate (BSS) for four weeks. The combination of BSS with amoxicillin, tinidazole or an H2-receptor antagonist offered no advantage over BSS alone. Treatment with BSS led to improvement in symptoms and histological findings including healing of ulcers in patients with or without persistent C.p. infection. The recurrence of C.p. infection after apparently successful treatment was, however, 75% in 4 weeks. In conclusion, C.p. infection correlates strongly with the presence of chronic gastritis, and significantly with gastric and duodenal ulceration. The best diagnostic approach is the combination of a rapid urease detecting test and histology. C.p. infection is of long duration and difficult to eliminate. The most effective treatment for C.p. infection remains BSS as single agent.

[Calculated initial chemotherapy in mechanically-ventilated postoperative patients with peritonitis, sepsis and pneumonia]. / Kalkulierte initiale Chemotherapie bei beatmeten postoperativen Patienten mit Peritonitis, Sepsis bzw. Pneumonie.

Calculated chemotherapy is based on the knowledge of the typical bacterial agents of a particular infection. From January 1983 to August 1985 bacteriological findings from surgical patients with peritonitis, septicemia or pneumonia treated in an intensive care unit were analysed. The study concentrated on those findings only which differed from previous bacteriological investigations. During the first three days 53 patients on assisted ventilation suffering from peritonitis exhibited mainly enterobacteria in their peritoneal secretions. At day 10 or later we also found bacteria from the pseudomonas group. At that time the bacterial spectrum of bronchial secretions was comparable to that of the peritoneal secretions of the same patient. After day 10, the bacterial spectrum was similar in 36 ventilated patients without peritonitis, in 56 patients suffering from post-operative pneumonia and in peritonitis patients. According to our findings, calculated chemotherapy may be based on the fact that patients with peritonitis who cannot be cured within a few days have a bacterial flora comparable to that of patients with septicemia or pneumonia. Patients with severe infections following surgery, such as potentially fatal pneumonia, generalised peritonitis or septicemia were treated with imipenem/cilastatin, according to the above definitions of calculated chemotherapy. 37 of 46 patients treated between May and December 1985, were clinically cured. Microorganisms persisted in five clinically cured patients. Development of resistance to imipenem was observed in one case. In one case treatment had to be stopped because of an allergic skin reaction. Monotherapy of peritonitis by imipenem/cilastatin appeared more satisfactory than treatment with combinations of other antibiotics.