Pseudomonas aeruginosa as a primary pathogen in children with bacterial peritonitis

This prospective study compared the efficacy of sulbactam/ampicillin and clindamycin/gentamicin in the treatment of children with bacterial peritonitis. Of the 29 children enrolled, 17 were evaluable; eight received sulbactam/ampicillin/gentamicin and nine clindamycin/gentamicin. Sixteen patients were previously healthy children with appendicitis. An average of 3.6 bacterial species were recovered from the peritoneal fluid of each patient. E coli and B fragilis were the most common aerobic and anaerobic isolates, recovered from 15 and ten patients, respectively. Pseudomonas aeruginosa was recovered from seven of 17 children; the three children with P aeruginosa infections randomized to the sulbactam/ampicillin group received gentamicin in addition to the investigational agents throughout the treatment course. Although the study groups were small, there was no difference in age, sex, number of pathogens per patient, duration of hospitalization, toxicity, or treatment failures between the two treatment groups or between children infected with P aeruginosa and controls. As a result of the high prevalence of P aeruginosa in the peritoneal exudate of otherwise healthy children with appendicitis, initial antimicrobial therapy in this patient population should include agents effective against this organism.     

Extrapulmonary sites of Pseudomonas aeruginosa in adults with cystic fibrosis.

BACKGROUND: Pseudomonas aeruginosa infection is seldom eradicated in patients with cystic fibrosis despite intensive antipseudomonal treatment. Upper airway sites of infection may contribute to perpetuation of lower airways infection. This study was designed to find out which extrapulmonary sites are infected and whether the strains at these sites are identical to those in the lungs. METHODS: Sputum and upper airway samples from 42 patients were cultured for P aeruginosa and stool samples from 20 patients were also tested. Nineteen isolates from sputum and extrapulmonary sites from four patients were genotyped with the pCM tox probe. RESULTS: P aeruginosa was isolated from the sputum of 36 patients, 34 of whom had infection in the upper airways. Six of the 20 patients tested were positive for P aeruginosa in the stool. The nasopharynx was colonised in 30 patients, the oropharynx in 29, the middle meatus in 13, the external nares in six, and the inferior turbinate in four. Three of four patients tested had the same strain of P aeruginosa (a different one in each individual) in the sputum and the upper airways, and in two of the three the stool isolate was a different strain. CONCLUSION: Most adults with cystic fibrosis and P aeruginosa pulmonary infection have upper airway reservoirs of the organism and strains from these sites are identical to those in the lungs.     

Ceftazidime treatment in cystic fibrosis: resistant organisms in sputum and faeces.

Ceftazidime was used as the only intravenous agent for treating lower respiratory tract infections in patients with cystic fibrosis. The risks of inducing beta lactamases and conferring antibiotic resistance are high when monotherapy is used; so the emergence of resistant bacteria was studied prospectively in the sputum of 120 patients. The mean age of patients was 9.0 (range 0.3-25) years and there were equal number of male and female patients. Pseudomonas aeruginosa was the only ceftazidime resistant bacterium to be isolated from the respiratory tract, and was identified only in chronically colonised patients. Ceftazidime resistance occurred in 103 (14%) of 750 P aeruginosa isolates, and in 16 of 36 chronically colonised patients. Ceftazidime resistant organisms were isolated from the faeces of 17 of 64 patients investigated. Eighty two per cent of the resistant faecal organisms were single isolates: the same resistant organism in faeces was isolated from successive samples in only two patients. In no case was the ceftazidime resistant enteric isolate the same as that from sputum. Patients chronically colonised by P aeruginosa did not harbour ceftazidime resistant enteric organisms any more than non-colonised patients. The use of ceftazidime as a single intravenous agent in treating chest exacerbations in cystic fibrosis does not induce a reservoir of ceftazidime resistant bacteria.     

Inhibitory effects of hypertonic saline on P. aeruginosa motility

Salt transport defects in CF lungs predispose to overwhelming and fatal respiratory infection caused by Pseudomonas aeruginosa. Motility of this organism is central to pathogenesis in a number of settings. Incubation of numerous strains of P. aeruginosa with hypertonic saline caused a concentration-dependent decrease in bacterial motility. Reduction of P. aeruginosa virulence through this effect may contribute to clinical efficacy of hypertonic saline aerosols in CF patients.     

Cross-colonisation with Pseudomonas aeruginosa of patients in an intensive care unit

BACKGROUND: Ventilator-associated pneumonia (VAP) caused by Pseudomonas aeruginosa is usually preceded by colonisation of the respiratory tract. During outbreaks, colonisation with P aeruginosa is mainly derived from exogenous sources. The relative importance of different pathways of colonisation of P aeruginosa has rarely been determined in non-epidemic settings. METHODS: In order to determine the importance of exogenous colonisation, all isolates of P aeruginosa obtained by surveillance and clinical cultures from two identical intensive care units (ICUs) were genotyped with pulsed field gel electrophoresis. RESULTS: A total of 100 patients were studied, 44 in ICU 1 and 56 in ICU 2. Twenty three patients were colonised with P aeruginosa, seven at the start of the study or on admission and 16 of the remaining 93 patients became colonised during the study. Eight patients developed VAP due to P aeruginosa. The incidence of respiratory tract colonisation and VAP with P aeruginosa in our ICU was similar to that before and after the study period, and therefore represents an endemic situation. Genotyping of 118 isolates yielded 11 strain types: eight in one patient each, two in three patients each, and one type in eight patients. Based on chronological evaluation and genotypical identity of isolates, eight cases of cross-colonisation were identified. Eight (50%) of 16 episodes of acquired colonisation and two (25%) of eight cases of VAP due to P aeruginosa seemed to be the result of cross-colonisation. CONCLUSIONS: Even in non-epidemic settings cross-colonisation seems to play an important part in the epidemiology of colonisation and infection with P aeruginosa.     

Diagnostic and prognostic value of serum antibodies against Pseudomonas aeruginosa in cystic fibrosis

BACKGROUND: Eradication of Pseudomonas aeruginosa in patients with cystic fibrosis (CF) is possible if initiated early in the course of colonisation. To detect P aeruginosa as early as possible is therefore a major goal. This study was undertaken to validate a commercialised test for the detection of serum Pseudomonas antibodies in patients with CF. METHODS: A representative cross sectional analysis of serum antibodies against three Pseudomonas antigens (alkaline protease, elastase, and exotoxin A) was performed in 183 patients with CF of mean age 16.7 years and FEV1 85.9% predicted. The results were correlated with microbiological results from the previous 2 years to calculate sensitivity, specificity, positive and negative predictive values. The following 2 years were assessed to determine prognostic predictive values. RESULTS: A combination of all three tested antibodies yielded the best results with a sensitivity of 86%, specificity of 96%, and a positive predictive value of 97%. These values were higher if only patients in whom sputum cultures were available were considered (n = 76, sensitivity 95%, specificity 100%, positive predictive value 100%). The prognostic positive predictive value was high in intermittently infected patients (83%) but low in patients free of infection (33%), whereas the prognostic negative predictive value was high in patients free of infection (78%) and low in intermittently infected patients (58%). CONCLUSIONS: Regular determination of serum antibodies may be useful in CF patients with negative or intermittent but not with positive P aeruginosa status. A rise in antibody titres indicates probable infection and eradication treatment may be initiated even in the absence of microbiological detection of P aeruginosa.     

Long term effect of erythromycin therapy in patients with chronic Pseudomonas aeruginosa infection.

BACKGROUND--Diffuse panbronchiolitis is a chronic infection of the lower respiratory tract common among the Japanese people, with a persistent Pseudomonas aeruginosa infection in the late stage and sustained neutrophil retention in the airways. The long term effect of erythromycin was examined retrospectively in a group of patients with diffuse panbronchiolitis, with and without P aeruginosa infection, and the relationship between drug-induced bacterial clearance and clinical improvement was investigated. METHODS--The history, daily volume of sputum, type of organisms in sputum cultures, pulmonary function tests, arterial blood gas tensions, and chest radiographs were compared in 16 patients with diffuse panbronchiolitis with P aeruginosa infection and 12 without. The total and differential cell counts in the bronchoalveolar lavage (BAL) fluid were compared in 14 of the 28 patients (five of whom were infected with P aeruginosa) before and after 1-12 months of treatment with erythromycin (600 mg/day). The outcome of treatment in patients showing clearance of organisms on repeated sputum cultures was compared with that in those demonstrating persistence of bacteria in the sputum and patients with normal flora. RESULTS--Erythromycin improved respiratory function and arterial blood gas tensions irrespective of the presence or absence of P aeruginosa in the sputum. Treatment also resulted in a reduction in the BAL fluid total cell count and the percentage of neutrophils in both groups of patients. There were no differences between patients in whom the bacteria cleared and those with persistent bacteria or patients with a normal flora with regard to the degree of improvement of respiratory function, arterial blood gas tensions, and BAL fluid cell composition. CONCLUSION--The results suggest that the efficacy of erythromycin in diffuse pan-bronchiolitis may be due to anti-inflammatory effect, independent of P aeruginosa infection or bacterial clearance.     

Pseudomonas aeruginosa bacteremia in patients undergoing liver transplantation: an emerging problem

In our institution, Pseudomonas aeruginosa bacteremia appeared to occur with increasing frequency in patients undergoing liver transplantation. We thus conducted a prospective study to define risk factors and outcome in these patients. Over a 19-month period 6% of liver transplants were followed by Pseudomonas bacteremia. The mean age was 46 years (range, 24 to 67 years). The interval between transplantation and onset of bacteremia was 3 to 372 days (mean, 80). The incidence of Pseudomonas bacteremia in liver transplants was three times that of other transplants (heart, lung, kidney). Ninety one percent of infections were nosocomial. Polymicrobial bacteremia occurred in 30% of episodes. The portal of entry was respiratory in 30%, abdominal in 35%, and biliary in 13%. Four patients had recurrent Pseudomonas bacteremia: liver abscess (1), biliary obstruction (2), subhepatic abscess (1). Survival at 14 days was 70%. Survival rates were significantly lower for patients with hypotension, on mechanical ventilators, and increasing severity of illness (p less than 0.05). Survival was higher when bacteremia occurred within the first 30 days after transplantation compared to after 30 days. A large number (43.4%) of Pseudomonas bacteremias occurred after transplant surgery of biliary tract manipulation, while the patient was receiving a prophylactic regimen of cefotaxime and ampicillin. P. aeruginosa is an important pathogen in the liver transplant recipient; prevention may be possible for a subgroup of patients with the use of prophylactic antibiotics with activity against P. aeruginosa.     

Genotyping of Pseudomonas aeruginosa in cystic fibrosis suggests need for segregation.

BACKGROUND: Emerging resistance of Pseudomonas aeruginosa within cystic fibrosis (CF) populations is attributed to antibiotic pressure and spread of transmissible strains. We describe increasing resistance of P. aeruginosa isolates, resulting in the identification of two multiresistant strains and their impact on morbidity. METHODS: Susceptibility reports of all P. aeruginosa isolates since 1998 in our unit were reviewed. Isolates were submitted for genomic finger-printing by pulsed-field gel electrophoresis. Clinical measures and the consumption of treatment resources were compared between those harbouring resistant organisms and those with sensitive strains. RESULTS: Analysis of 407 reports from 43 patients revealed isolation of multiresistant (MR) organisms increased during 1999. Those harbouring MR strains consumed more resources than non-MR. Strain typing showed a new 'Sheffield' strain in seven patients (100% MR), and the 'Liverpool' strain in 10 patients (40% MR). Individuals in these groups consumed significantly more resources than 23 patients with unique, susceptible strains (4% MR). DISCUSSION: Increasing resistance in isolates of P. aeruginosa may herald the arrival of a transmissible strain in CF Units which though sometimes sensitive, may become multiply resistant and require more intensive treatment. We now segregate those with transmissible strains from each other and from those with unique strains.     

Community acquired lobar pneumonia in patients with HIV infection and AIDS.

BACKGROUND--Community acquired bacterial pneumonia is increasingly encountered in HIV infected individuals and some patients have a radiographic lobar pneumonia. METHODS--A retrospective review of clinical features, microbiological diagnosis, and outcome of community acquired lobar pneumonia was carried out in HIV positive patients admitted to a specialist unit from 1987 to 1993. RESULTS--Forty nine episodes occurred in 45 patients, all of whom were men. CD4 counts ranged widely. A bacteriological diagnosis was made in 25 episodes (51%), seven patients had more than one infective cause. The commonest pathogens were Streptococcus pneumoniae (11 episodes), Staphylococcus aureus (six), Pneumocystis carinii (three), Haemophilus influenzae (three), and Pseudomonas aeruginosa (two). Four patients died. Other complications included intrapulmonary cavitation or abscess formation (11 episodes), empyema (three), and pleural effusion (10 episodes). CONCLUSIONS--Many different infections cause community acquired lobar pneumonia in HIV positive men. Some patients have co-infections and there is a high complication rate.     

Adult cystic fibrosis: association of acute pulmonary exacerbations and increasing severity of lung disease with auxotrophic mutants of Pseudomonas aeruginosa.

BACKGROUND--Pseudomonas aeruginosa has been located in the endobronchiolar spaces of patients with cystic fibrosis where nutrients may be limited. In these sites it is thought that adaptation of the pathogen might occur and growth factors, present in relative excess, may thus promote survival of the organism. Auxotrophy of pulmonary isolates of P aeruginosa has previously been shown to be a feature of cystic fibrosis and chronic lung sepsis; auxotrophic isolates have additional nutritional requirements to the prototrophic "wild types" of the species. A study was therefore carried out to determine whether the proportion of auxotrophs differs between stable and acutely ill patients, or correlates with the extent of underlying disease. METHODS--Sputum samples were cultured for P aeruginosa and tested for auxotrophy by spreading serial dilutions of homogenised sputum on to a minimal medium which supports only prototrophs, and a complete medium which supports both nutritional types. The proportion of auxotrophs to prototrophs was determined and growth factors of confirmed auxotrophs were identified. RESULTS--Thirty two (86%) of 37 adults with cystic fibrosis infected with P aeruginosa harboured auxotrophs; methionine dependent mutants were isolated from seven of 16 patients tested (44%). More than 50% of the total number of colonies were auxotrophic in 19 of 26 samples (73%) from patients with acute exacerbations and in only six of 15 samples (40%) from clinically stable patients. In four patients from whom samples in both the acute and stable states were available, the proportion of auxotrophs fell in the sample taken when stable. Auxotrophs predominated in all samples from 11 of those patients with very severe underlying lung disease, in contrast to 13 of 30 samples from patients with less severe disease. There was no association between the percentage of auxotrophs and the presence of other respiratory pathogens. CONCLUSIONS--The majority of adults with cystic fibrosis infected with P aeruginosa harbour auxotrophs in the sputum. A significant proportion of acutely ill patients and those with severe underlying disease have a preponderance of auxotrophs in the sputum compared with stable patients and those with less severe disease.     

Mycobacterial infection in HIV seropositive and seronegative populations, 1987-93.

BACKGROUND--Although the causes of the worldwide resurgence of tuberculosis are multifactorial, the HIV epidemic is believed to have had a central role. Control is further threatened by the emergence of multidrug-resistant tuberculosis. METHODS--A retrospective evaluation was undertaken of trends in pulmonary and extrapulmonary culture positive mycobacterial pathology, and the prevalence of drug-resistant tuberculosis in both HIV seropositive and, presumptively, HIV seronegative patients receiving their clinical care at St Mary's Hospital, London. Five hundred and thirty eight patients (188 of whom were known to be HIV seropositive) with positive mycobacterial isolates between January 1987 and March 1993 were identified from laboratory records. These were cross referenced with drug surveillance records. RESULTS--Overall, between 1987 and 1992 there was a progressive 3.5 fold increase in positive mycobacterial isolates and a 2.5 fold increase in patients with proven mycobacterial infection. This increase was greater within the HIV seropositive population. A total of 663 positive mycobacterial isolates was evaluated; the major pathogen identified was Mycobacterium tuberculosis (379 isolates, 57%). Three hundred and fourteen patients were diagnosed as having M tuberculosis, 49 of whom were HIV seropositive. M tuberculosis was predominantly isolated from the lung. Of 358 positive cultures for M tuberculosis (68 HIV seropositive, 290 presumptively HIV seronegative), only 27 isolates (7.6%), almost exclusively derived from presumed HIV seronegative patients, were resistant to either isoniazid, rifampicin, or both drugs together. No increases in drug-resistant isolates were observed over this period. CONCLUSIONS--There has been a considerable increase in the incidence of tuberculosis in both HIV seronegative and seropositive populations during the study period. The emergence of drug-resistant tuberculosis was not observed.     

Biofilm formation by Staphylococcus aureus and Pseudomonas aeruginosa is associated with an unfavorable evolution after surgery for chronic sinusitis and nasal polyposis

OBJECTIVES: To determine whether biofilm-forming capacity of bacteria demonstrated in chronic rhinosinusitis (CRS) has an impact on persistence of the disease following endoscopic sinus surgery (ESS). METHOD: Thirty-one bacterial strains recovered from 19 patients with CRS at least 1 year post-ESS. Evolution of disease was assessed by questionnaire and endoscopy as favorable or unfavorable. The bacteria were cultured on a 96-well culture plaque and a semi-quantitative method using crystal violet to quantify biofilm production was used. RESULTS: Twenty-two of 31 samples produced a biofilm thicker or equal to the positive control. Biofilm production was noted in 6/10 Pseudomonas aeruginosa isolates, 8/10 Staphylococcus aureus, and 8/11 coagulase-negative staphylococci. Biofilm formation was associated with a poor evolution for Pseudomonas aeruginosa and Staphylococcus aureus, but not coagulase-negative staphylococcus. CONCLUSION: There is a correlation between in vitro biofilm-producing capacity by Pseudomonas aeruginosa and Staphylococcus aureus and unfavorable evolution after ESS, suggesting a role for biofilm production in chronic sinusitis. EBM RATING: B-2b.     

Outbreak of pseudomonas aeruginosa by multiple organ transplantation from a common donor

Transmission of bacterial infections from donor to recipient may occur with donor bacteremia. We describe a novel mechanism for transmission of Pseudomonas to multiple recipients through direct contamination of a donor innominate artery graft. Patient data were collected by chart review from the donor and the kidney, kidney-pancreas, heart, lung, and liver recipients. The donor was not bacteremic but had P. aeruginosa isolated from routine tracheal cultures. Spillage of tracheal contents onto the innominate artery and subsequent contamination of intra-abdominal organs likely occurred. Vascular anastomotic infections with graft loss caused by Pseudomonas occurred in three patients (liver, kidney, and kidney-pancreas), and the lung patient developed severe pneumonia. All Pseudomonas isolates were identical by molecular typing. Donors may transmit bacterial infections to multiple recipients by mechanisms other than donor bacteremia. Although donor tracheal cultures are commonly positive, in certain settings antimicrobial treatment of recipients may be needed.     

Increased plasminogen activator inhibitor-1 concentrations in bronchoalveolar lavage fluids are associated with increased mortality in a cohort of patients with Pseudomonas aeruginosa

BACKGROUND: Increased plasminogen activator inhibitor-1 (PAI-1) concentrations are found in bronchoalveolar lavage (BAL) fluids from patients with ventilator-associated pneumonia or acute respiratory distress syndrome. The authors hypothesized that PAI-1 concentrations were associated with increased mortality in patients with either Pseudomonas aeruginosa-induced ventilator-associated pneumonia or tracheobronchial colonization. METHODS: In a prospective cohort study, daily aspirates from intubated patients were cultured for P. aeruginosa. Positive patients had blind BAL (bBAL) that was processed for biomarker concentrations. Secretion of type III secretion cytotoxins were also analyzed from the P. aeruginosa strains. RESULTS: Thirty-three patients were enrolled. Ten of the 33 patients died. bBAL PAI-1 concentrations were significantly increased in nonsurvivors compared with survivors (31.7 vs. 3.4 ng/ml, P = 0.001 for hospital mortality; 35.9 vs. 4.7 ng/ml, P = 0.02 for 28-day mortality). Even when acute respiratory distress syndrome patients were excluded, there was a significant difference between the survivors and nonsurvivors for bBAL PAI-1 concentrations (P = 0.005). Eighty-three percent of P. aeruginosa strains isolated from patients with high concentrations of bBAL PAI-1 also had strains that secreted cytotoxins. CONCLUSIONS: PAI-1 concentrations in bBALs correlated with mortality in ventilated patients with positive cultures for P. aeruginosa. Elevated bBAL PAI-1 concentrations also correlated with the secretion of type III exotoxins by P. aeruginosa.     

Seasonal onset of initial colonisation and chronic infection with Pseudomonas aeruginosa in patients with cystic fibrosis in Denmark.

BACKGROUND AND METHODS: To assess the relation between seasonal variation and the onset of initial and chronic Pseudomonas aeruginosa infection, 300 Danish patients with cystic fibrosis were investigated. A retrospective analysis based on case reports was performed to identify the date and year of initial and chronic P aeruginosa infection from 1965 to 1990. RESULTS: Sixty six per cent of the patients contracted their initial P aeruginosa colonisation and 68% contracted chronic infection during the winter months (October to March). Despite major changes in treatment, including improved and intensified antibiotic treatment, during the investigation period in our cystic fibrosis centre, the seasonal difference in P aeruginosa infection persisted. CONCLUSIONS: As respiratory virus infections have the same seasonal distribution in Denmark such infections may pave the way for P aeruginosa and thus explain the parallel seasonal occurrence of this pathogen in patients with cystic fibrosis.     

Bacteriology of burns at the Queen Elizabeth Central Hospital,Blantyre, Malawi

A retrospective study to determine the bacterial profile and antibiotic susceptibility pattern of burn isolates at the Queen Elizabeth Central Hospital (QECH), Blantyre, Malawi was undertaken. While a total of 1825 burn patients were admitted to the hospital over a 6-year period (January 1994 to December 1999) only 317 (17.4%) specimens selected from as many patients were processed. One hundred and seventy (170/53.6%) specimens yielded single while the rest (147/46.4%) had multiple isolates giving a total of 535 bacterial isolates. Of this number, 236 (44.1%) were Gram-negatives and 299 (55.9%), Gram-positives. Among the Gram-negatives, Pseudomonas aeruginosa, Proteus mirabilis, Coliforms/Escherichia coli and Klebsiella pneumoniae were the most common accounting for 94.1% while in the Gram-positive group, staphylococcal and streptococcal spp. predominated (100%). However, the three most common isolates were Staphylococcus aureus (37.6%), P. aeruginosa (22.4%) and beta-haemolytic streptococci (13.6%). While S. aureus and beta-haemolytic streptococci were most susceptible to penicillin (33.3 and 64.4% susceptibility, respectively), gentamycin appeared most effective against P. aeruginosa (53.3%). A general broad-spectrum resistance to panels of antibiotics used in the study was however observed among the bacterial isolates. From these results, S. aureus, P. aeruginosa, streptococcal spp., P. mirabilis, Coliforms and K. pneumoniae representing 96.4% of all isolates were the most common in the Burns Unit.     

Pulmonary complications of HIV disease: 10 year retrospective evaluation of yields from bronchoalveolar lavage, 1983-93.

BACKGROUND--Pulmonary disease is a major contributor to morbidity and mortality in patients with HIV infection and AIDS. The aim of this study was to describe bronchoscopic findings and the spectrum of pulmonary pathogens in HIV seropositive patients undergoing investigation of respiratory disease over a 10 year period in a major UK referral centre. METHODS--Recruitment was procedure based with data being captured when bronchoscopy was clinically indicated. Data were evaluated from 580 HIV seropositive patients (559 men, age 13-65 years) over a 10 year period from June 1983 to March 1993. RESULTS--A total of 947 bronchoscopies was performed. The most frequent pulmonary pathogen isolated from bronchoalveolar lavage (BAL) fluid in 44% of all bronchoscopies was Pneumocystis carinii. Of all patients studied, 324 (55%) had at least one cytologically confirmed episode of P carinii pneumonia; this was AIDS defining in 219 (38%) of patients who underwent bronchoscopy. Between 1987 and 1993 the overall diagnostic yield from BAL fluid was 76%; 25% of all bronchoscopies yielded positive microbiological results, the most frequent isolates being Staphylococcus aureus, Streptococcus pneumoniae, Pseudomonas spp, and Haemophilus influenzae. Mycobacteria were identified in 8% of patients; M tuberculosis was the most common being identified in 3% of lavage samples and in 4% of patients. No drug-resistant M tuberculosis was found. Viral isolates (mainly cytomegalovirus) were identified in up to 31% of BAL fluid samples. Endobronchial Kaposi's sarcoma was seen in 15% of patients at bronchoscopy. CONCLUSIONS--Of the 1956 newly diagnosed HIV seropositive patients receiving clinical care at St Mary's Hospital over this period, approximately 30% underwent bronchoscopy. Diagnostic rates for P carinii pneumonia, endobronchial Kaposi's sarcoma, and bacterial and mycobacterial infection have remained largely constant since 1989. Bronchoalveolar lavage produces high diagnostic yields generally, and P carinii pneumonia remains a common cause of pulmonary disease in these patients.     

Regimens for eradicating early Pseudomonas aeruginosa infection in children do not promote antibiotic resistance in this organism

BACKGROUND: This study was designed to address the concern that intensive regimens to eradicate early Pseudomonas aeruginosa infection in patients with cystic fibrosis may lead to the emergence of antibiotic-resistant isolates. METHODS: Data was analysed retrospectively over a 10 year period at the Leeds Regional Paediatric Cystic Fibrosis Centre. All patients with first-ever isolation of P. aeruginosa who successfully completed an eradication regimen were included. Antibiotic sensitivities of P. aeruginosa were compared between initial and subsequent re-isolations in patients where eradication was successful and in those where treatment had failed. RESULTS: Forty one patients with first acquisitions for P. aeruginosa and who completed eradication treatment were identified. Eradication treatments consisted of oral, intravenous, nebulised antibiotics or a combination of these. The antibiotic sensitivity of P. aeruginosa in first growths was high and remained so on subsequent re-isolations. A repeated measures logistic model found no significant difference with time of isolation. There was no statistically significant difference in antibiotic sensitivity between P. aeruginosa isolated after successful and failed eradication. CONCLUSIONS: Repeated intensive regimens for P. aeruginosa eradication did not result in a significant increase in overall antibiotic resistance between initial and subsequent growths of this organism over the period of this study.     

Pseudomonas aeruginosa bacteraemia in an academic hospital in South Africa

OBJECTIVES: The aim of the study was to determine the clinical manifestations, outcome of and prognostic factors associated with Pseudomonas aeruginosa bacteraemia at Chris Hani Baragwanath Hospital, Johannesburg, during the period 1998 - 1999, to describe and quantify resistance to antipseudomonal drugs, to characterise bacteraemic isolates, and to investigate the clustering and genotype distribution of drug-susceptible and multiply-resistant strains in the hospital. METHODS: Clinical and laboratory investigations, culture and antimicrobial susceptibility testing were performed. Bacteraemic isolates were typed by endonuclease macrorestriction. Those with > or = 97% band pattern similarity were assigned genotype status. RESULTS: Of 91 P. aeruginosa blood isolates, 52 (57.1%) were nosocomially acquired. Underlying conditions associated with episodes were burns in 24 (28%) and HIV infection in 21 (24%). Multidrug resistance was present in 14 (15.4%) of isolates from 91 episodes. In 79 episodes where the outcome was known, 37 (46.8%) of the patients died. Case fatality rates were 75% in adults and 25% in children. Being a child, receiving appropriate antimicrobial treatment and admission to a specialised care unit were significantly associated with improved prognosis. CONCLUSION: P. aeruginosa bacteraemia was associated with outbreaks caused by two multiply-resistant genotypes. Eighteen antimicrobial-susceptible isolates from bacteraemic episodes in paediatric wards, 9 in HIV-seropositive children, could be linked to small outbreaks in both hospitalised and community-based children.