Microbial contamination of nebulizers in the home treatment of cystic fibrosis

BACKGROUND: Home nebulizers are in widespread use in cystic fibrosis (CF) and other chronic pulmonary diseases. Bacterial contamination may be a source of respiratory tract colonization. OBJECTIVES: To investigate microbial contamination of home nebulizers in CF patients, compare with sputum cultures and relate to cleaning practices. METHODS: A total of 29 home nebulizers of CF patients were cultured. Families were interviewed regarding cleaning routines and patients had sputum cultures for bacteria and fungi. RESULTS: In total, 19/29 (65%) nebulizers were contaminated: 18 reservoir cups, 14 mouthpieces and five filters. Pseudomonas spp. were isolated from 10 nebulizers (35%) and all 10 had Pseudomonas aeruginosa airway infection although without genetic typing we could not be sure this was the same bacteria as that from their nebulizer unit. An additional 7/29 had Pseudomonas aeruginosa airway infection without a contaminated nebulizer (P=0.001). No nebulizers were contaminated with Aspergillus. Only 4/19 contaminated nebulizers (22%) had been cleaned after every use, compared with seven of the 10 (70%) uncontaminated nebulizers (P=0.017). Only 7/19 patients with contaminated nebulizers (37%) and 5/10 with clean nebulizers (50%) recalled receiving cleaning instructions (not significant). CONCLUSIONS: Home nebulizers are frequently contaminated, particularly when cleaning instructions are inadequate, and may be a source of airway infection or reinfection especially following contamination from a patient chronically colonized with P. aeruginosa. Simple oral and written cleaning instructions should be offered.     

Microbiologic data overview of Italian cystic fibrosis patients

The aim of our study was to determine the frequency of microbiological culturing and prevalence of colonization by principal pathogens of the respiratory tract of Italian cystic fibrosis patients. Data on all Italian cystic fibrosis patients were collected using a questionnaire sent to all Italian CF Centers. Results were obtained of microbiological cultures from 2,521 patients. Information was gained regarding the method of gathering biological samples, the percentage of patients undergoing microbiological culturing regularly, the procedures used to isolate bacteria and types of culture media used which were selective for Burkholderia cepacia. Ninety-four percent of Italian CF patients are regularly tested microbiologically. Sputum and pharyngeal cultures are most often carried out. 49% of Italian patients are colonized by Staphylococcus aureus, 5.4% by Haemophilus influenzae, 48.9% by Pseudomonas aeruginosa and 3.8% by Burkholderia cepacia. In Italy there is a high prevalence of CF patients colonized by Staphylococcus aureus and a low prevalence of patients colonized by Haemophilus influenzae. The prevalence of Burkholderia cepacia and Pseudomonas aeruginosa does not differ significantly from other countries examined.     

The impact of pan-resistant bacterial pathogens on survival after lung transplantation in cystic fibrosis: results from a single large referral centre

Reported actuarial one-year survival for patients with cystic fibrosis (CF) after lung transplant is 55-91%. Infection is the most common cause of early death. Colonization with Burkholderia cepacia complex is associated with reduced survival and international lung transplant referral guidelines support individual unit assessment policies for patients colonized with other pan-resistant bacteria. We examined local data on survival after transplant for CF to determine the impact of colonization with pan-resistant bacteria. A retrospective review of all CF patients from Royal Prince Alfred Hospital (RPAH), Sydney, who underwent lung transplantation at St Vincent's Hospital, Sydney, 1989-2002, was performed. Sixty-five patients were listed for lung transplantation with 54 (male: female=29:25) receiving transplants. Of the 11 patients (17%) who died on the waiting list, six were colonized with pan-resistant Pseudomonas aeruginosa. Thirty of the 54 transplanted patients had at least one pan-resistant organism before transplant. In 28 this included P. aeruginosa. Overall one-year survival was 92% with a median survival of 67 months. Overall survival for the pan-resistant group (N = 30) was not significantly different to survival in those with sensitive organisms (N = 24) (Logrank chi square = 1.6, P = 0.2). Three patients colonized with B. cepacia complex pre-transplant survive at 11, 40 and 60 months post-transplant. Infection contributed to 11 of the 18 post-transplant deaths, with pre-transplant-acquired bacterial pathogens responsible in two cases. Patients continued to acquire multiresistant bacteria post-transplantation. Lung transplant survival at St Vincent's Hospital for CF adults from RPAH compares favourably with international benchmarks. Importantly, colonization with pan-resistant bacteria pre-transplant did not appear to adversely affect survival post-transplant.     

Isolation of infectious cystic fibrosis patients: results of a systematic review.

OBJECTIVE: Respiratory tract infections significantly contribute to morbidity and mortality among cystic fibrosis (CF) patients. Therefore, pathogen transmission needs to be prevented. There are several guidelines for the care of CF patients, but no transparent systematic literature review has been published. METHODS: We conducted a systematic literature review (January 1966 to September 2004) dealing with segregation of CF patients colonized with Burkholderia cepacia species, Pandoraea species, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, or Alcaligenes species. Quality of studies was evaluated by taking patient population size, existence of control-patients, patient randomization, diagnostic approach, and bacteria typing methods into account. RESULTS: One hundred ninety-nine studies were found. Evidence and quality of 102 publications were evaluated. In 99 publications, recommendations concerning segregation measures for infectious CF patients were determined including a total of 11,576 patients. No randomized, controlled trials had been conducted. Fifty of 56 authors strongly recommended isolation of CF patients infected with B. cepacia or Pandoraea species. In 31 of 39 studies, interpatient spread of Pseudomonas aeruginosa was documented or had been brought to an end by isolation of patients. Only five studies had addressed S. maltophilia or Alcaligenes species. CONCLUSIONS: Patients colonized with B. cepacia or Pandoraea species are to be separated from noncolonized patients in single rooms. Patients harboring multidrug-resistant Pseudomonas aeruginosa, S. maltophilia, or Alcaligenes species may not share a room with immunocompromised patients, in intensive care units, or with other CF patients anywhere in the hospital.     

Genotyping of Pseudomonas aeruginosa sputum and stool isolates from cystic fibrosis patients: evidence for intestinal colonization and spreading into toilets

Three hundred and fifty-eight stool and 131 sputum specimens from 40 cystic fibrosis (CF) patients and 100 toilet sinks were investigated for occurrence of Pseudomonas aeruginosa; 67% (21/31) of the patients with chronic P. aeruginosa lung infections carried the organism repeatedly in the stool but the organism was found only once in the stools of nine uninfected patients. P. aeruginosa stool carriage was correlated to high P. aeruginosa numbers in patients' sputa. Typing of P. aeruginosa with a DNA probe showed identity of sputum and stool strains. Seven patients repeatedly carried additional stool strains, not found in the sputum, suggesting intestinal colonization. No differences were seen in the clinical state of patients with P. aeruginosa-negative stool samples and patients with positive stool samples. Toilets in households of P. aeruginosa-infected CF patients were significantly more often contaminated with P. aeruginosa (42%) than toilets in households of non-infected CF patients (20%; P less than 0.03). The study shows that P. aeruginosa-infected CF patients may harbour the organisms also in the intestinal tract, and may spread the bacteria into toilets.     

Presence of polyclonal Pseudomonas aeruginosa in an intensive care unit: a 27-month prospective study on molecular epidemiology.

Pseudomonas aeruginosa was isolated in 22.2% of 305 intensive care unit environmental cultures. A high genetic heterogeneity (18 pulsotypes) was evident. Taps and related surfaces were a stable reservoir for certain pulsotypes. The 15.4% of the P. aeruginosa-positive cultures were polyclonal. Different colony morphotypes should be assayed in surveillance studies.     

Environmental contamination with an epidemic strain of Pseudomonas aeruginosa in a Liverpool cystic fibrosis centre, and study of its survival on dry surfaces

We conducted an environmental survey in the Liverpool adult cystic fibrosis (CF) centre in order to determine the extent of environmental contamination with an epidemic strain of Pseudomonas aeruginosa that colonizes most CF patients in Liverpool, and to identify possible reservoirs and routes of cross-infection. In addition, we studied the survival of this strain on dry surfaces, compared with that of other CF P. aeruginosa strains, to explore factors that might contribute to its high transmissibility. Samples were collected from staff, patients and the environment (drains, bath tubs, showers, dry surfaces, respiratory equipment and air) in the inpatient ward and outpatient clinic. P. aeruginosa strains were tested using a new polymerase chain reaction amplification assay specific for the Liverpool epidemic strain (LES). LES was isolated from patients' hands, clothes and bed linen. Environmental contamination with LES was only detected in close proximity to colonized patients (external surfaces of their respiratory equipment, and spirometry machine tubing and chair) and was short-lived. No persistent environmental reservoirs were found. LES was detected in the majority of air samples from inside patients' rooms, the ward corridor and the outpatient clinic. Survival of LES on dry surfaces was significantly longer than that for some other strains tested, but not compared with other strains shown not to be transmissible. Improved environmental survival on its own, therefore, cannot explain the high transmissibility of this epidemic strain. Our study suggests that airborne dissemination plays a significant role in patient-to-patient spread of LES, and confirms the need to segregate those patients colonized by epidemic P. aeruginosa strains from all other CF patients.     

Nosocomial Pseudomonas aeruginosa conjunctivitis in a pediatric hospital

Conjunctivitis accounted for 5% of nosocomial infections occurring in a university-affiliated pediatric hospital between January 1984 and April 1986. Pseudomonas aeruginosa was recovered from the conjunctiva of 30 patients. The primary diseases of these patients were chronic and debilitating. Eighty percent of patients were under 18 months of age although only 30% of admissions are represented in this age group. Seventy percent of cases occurred in pediatric intensive care unit/neonatal intensive care unit patients. Seventy percent of patients who had antecedent nasopharyngeal/endotracheal cultures obtained were colonized with P aeruginosa. All patients except one had one or more of the following interventions prior to the onset of conjunctivitis: tracheostomy, endotracheal tube, oxygen by hood, or suctioning. Two children (7.4%) have residual corneal scars. Improvements in eye care including protection of the eye during suctioning, other respiratory care, and nasogastric tube procedures are warranted.     

Low level of bacterial contamination of mist tents used in home treatment of cystic fibrosis patients

Mist tents are recommended by the Stockholm cystic fibrosis (CF) centre for small children with CF. Daily disinfection of some parts of the tent with 2% acetic acid is recommended, and for other parts boiling water followed by air-drying without rinsing. The plastic tent is discarded each day. We have studied whether these prescribed routines are followed by the patients and whether they are sufficient to prevent bacterial contamination. The mist tent equipment of 20 CF patients (mean age 7 years, range 1-15 years), two of whom were chronically colonized with Pseudomonas aeruginosa, were investigated. All patients were visited at home in the morning after 6-12 hours aerosol therapy. Liquid from the nebulizing chambers and swabs from the aerosol tube were examined by culture on four different media. Seventeen of 20 patients claimed that they cleaned and disinfected the tubes every day, two patients every other day and one once a week. Seventeen of 19 claimed they cleaned and disinfected the chambers daily, one once a week and, one twice a week. No or insignificant growth was found in 16/20 aerosol tubes: moulds in three, Pseudomonas species in one. Twelve of 19 chambers showed no or insignificant growth: moulds or yeasts were present in three and Pseudomonas sp. in four. In four of the seven patients moulds or yeasts and/or Pseudomonas sp. grew both from chambers and from aerosol tubes; in the remaining three only from chambers. None of these seven patients had followed our prescribed cleaning and disinfection recommendations, the other 13 claimed they had. Of the patients whose equipment yielded Pseudomonas sp, none was colonized with these strains, although one had P. aeruginosa. We conclude that our disinfection recommendations are adequate when followed. However, our disinfection recommendations concerning the nebulizing chamber had not been followed satisfactorily. The different forms of non-compliance would not have been detected without a home visit, emphasizing the importance of such visits. The importance of drying the equipment and of using the correct concentration of acetic acid is stressed.     

Effect of Pseudomonas cepacia colonization on survival and pulmonary function of cystic fibrosis patients

We conducted a historical prospective study of 124 cystic fibrosis (CF) patients colonized with Pseudomonas cepacia (cases) and 124 sex and age matched non-colonized CF patients (controls). Thirty-two of the colonized patients died in the first year following P. cepacia colonization compared to 8 of the control patients, a highly significant difference (p less than 0.001). In the second year, there was no significant difference in mortality between the two groups. Cases as a group had poorer pulmonary function and chest X-ray scores than controls up to 2 years before P. cepacia first appeared in their sputum or throat cultures. Regression analysis of pulmonary function tests (percent predicted FEV1 and RV/TLC) for each subject from 3 years before to 2 years after colonization revealed significant differences between cases and controls in slope for FEV1 and in slope and intercept for RV/TLC. When compared separately according to gender, the differences between cases and controls are significant in females but not in males. These results suggest that patients with poor pulmonary function are more prone to colonization with P. cepacia, that a subgroup of these patients will be dramatically affected and die within a year, and that the organism continues to exert a less dramatic negative effect on the pulmonary function of those patients who survive the initial acute effects of colonization, particularly in female patients.     

Randomized placebo-controlled clinical trial of immunoglobulin Y as adjunct to standard supportive therapy for rotavirus-associated diarrhea among pediatric patients

This study aims to evaluate the effect of hyperimmune immunoglobulin Y (IgY) against human rotavirus (HRV) among pediatric patients receiving standard supportive treatment for rotavirus-associated diarrhea mostly with an enteric non-cholera co-pathogen in a hospital setting. Two natural HRV reassortant clinical strains ATCC VR 2273 and ATCC VR 2274 were used as mixed immunizing antigens in poultry hens to generate anti-HRV IgY (Rotamix IgY). The Rotamix IgY was used in laboratory and clinical studies against control or placebo IgY. The control or placebo IgY was prepared using tissue culture medium from mock-infected MA104 cell line as antigen for poultry immunization. In vitro, Rotamix IgY exhibited multi-serotypic cross neutralization activities along with synergistic effects against major global serotypes G1, G2, G3, G4 and other human or animal rotavirus strains when compared with mono-specific IgY. Suckling mice (ICR strain) pre-treated orally once with Rotamix IgY and then challenged with rotavirus 3h later showed a significant dose-dependent reduction in frequency (p<0.05) and duration (p<0.05) of diarrhea compared to placebo IgY-treated mice. Out of 114 children aged between 3 and 14 months and with diarrhea upon admission in a Myanmar hospital, 54 dehydrated and rotavirus-positive children were randomized into Rotamix IgY group and placebo IgY group. Of these, only 52 children had complete data with n=26 children per study group. Ninety-two percent of patients in each of these groups were positive for co-infecting enteric non-cholera pathogen and all patients received standard supportive therapy for diarrhea. The patients were monitored for volume and duration of oral rehydration fluid (ORF) and intravenous fluid (IVF) intake, daily stool frequency and overall duration of diarrhea, and frequency and duration of rotavirus shedding. Compared to placebo IgY group, the Rotamix IgY group had statistically significant reduction in mean ORF intake (p=0.004), mean duration of intravenous fluid administration (p=0.03), mean duration of diarrhea from day of admission (p<0.01) and mean duration of rotavirus clearance from stool from day of admission (p=0.05). Overall, our novel approach using oral Rotamix IgY for rotavirus-infected children mostly with non-cholera enteric pathogen co-infection appears to be a promising, safe and effective adjunct to management of acute diarrhea in pediatric patients.     

An outbreak of Pseudomonas aeruginosa pneumonia and bloodstream infection associated with intermittent otitis externa in a healthcare worker.

OBJECTIVES: To investigate an outbreak of Pseudomonas aeruginosa pneumonia and bloodstream infection among four neonates, determine risk factors for infection, and implement preventive strategies. DESIGN: Retrospective case finding; prospective surveillance cultures of patients, personnel, and environmental sites; molecular typing by pulsed-field gel electrophoresis; and a matched case-control study. PATIENTS AND SETTING: Neonates in the level-III neonatal intensive care unit of a tertiary-care pediatric institution. INTERVENTIONS: Cohorting of patients with positive results for P. aeruginosa, work restrictions for staff with positive results, implementation of an alcohol-based hand product, review of infection control policies and procedures, and closure of the unit until completion of the investigation. RESULTS: Seven (4%) of 190 environmental cultures and 5 (3%) of 178 cultures of individual healthcare workers' hands grew P. aeruginosa. All four outbreak isolates and one previous bloodstream isolate were genotypically identical, as were the P. aeruginosa isolates from the hands and external auditory canal of a healthcare worker with intermittent otitis externa. Four of 5 case-patients versus 5 of 15 matched control-patients had been cared for by this healthcare worker (P = .05). The healthcare worker was treated and no further cases occurred. CONCLUSIONS: These findings suggest that a healthcare worker with intermittent otitis externa may have caused this cluster of fatal P. aeruginosa infections, adding the external ear to the list of colonized body sites that may serve as a source of potentially pathogenic organisms.     

Surveillance of Pseudomonas aeruginosa-isolates in a neonatal intensive care unit over a one year-period

Outbreaks of gram-negative bacteria such as Pseudomonas aeruginosa in neonatal intensive care units (NICU) can be life-threatening to pre-term infants, which are highly susceptible to serious infections with bacteria. Forty-two ventilated neonates in the NICU of the University Children's Hospital of Tuebingen were found to be colonized (n = 40) or infected (n = 2) with P. aeruginosa within a sampling period of one year. To investigate the colonization patterns and identify potential outbreak sources, epidemiological investigations, environmental surveillance and typing by serotyping and pulsed-field gel electrophoresis of the recovered isolates were performed. The investigation demonstrated a genetically related cluster of P. aeruginosa isolates during the surveillance period in 39 neonates and a second cluster at the end of the period in two neonates. A third strain representing a genetically distinct group was found in only one patient. Environmental investigations demonstrated the presence of P. aeruginosa in the ventilation equipment of 22 patients: binasal prongs (n = 22), water reservoir (n = 9), and heater (n = 1). In one case, P. aeruginosa was found in breast milk. Other environmental investigations revealed no P. aeruginosa. Although no evidence for a unique source was found, a series of intervention steps were initiated by the NICU personnel, medical microbiologists and infection control experts. The intervention steps included reinforced training of health care staff and a change from chemical to thermal disinfection of binasal prongs. Implementation of these measurements successfully stopped the recurrent occurrence of P. aeruginosa colonization.     

Common RAPD pattern of Pseudomonas aeruginosa from patients and tap water in a medical intensive care unit

The epidemiology of Pseudomonas aeruginosa infections and colonizations was studied prospectively on a 12-bed medical intensive care unit. Patients were monitored for P. aeruginosa colonization by performing throat swabs or tracheal aspirates on admission and weekly thereafter over a period of 6 months. Cultures of possibly infected sites were taken as clinically indicated. Water samples from all patient care-related tap water outlets were collected in 2-weekly intervals and examined for the presence of P. aeruginosa. Strains isolated from patients and water samples were analysed by serotyping and random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) typing. During the 6-month period, 60 of 143 (42%) water samples contained P. aeruginosa at various levels ranging from 1 to >100 colony-forming units per 100ml sample. Genotypically, water samples contained 8 different clonotypes. Nine patients had infections due to P. aeruginosa and 7 patients were colonized. Isolates from patients showed a similar distribution of genotypes as did tap water isolates, and strains of identical genotype as patient strains had been isolated previously from tap water outlets in 8 out of 16 (50%) infection or colonization episodes. However, patients also harboured strains not previously isolated from tap water. Thus, in addition to tap water, other environmental or unknown reservoirs appeared to play a role for the epidemiology of P. aeruginosa infections on this ward. However, because tap water played a significant role for strain transmissions, we conclude that intensified water site care is justified.     

Pseudomonas surgical-site infections linked to a healthcare worker with onychomycosis.

OBJECTIVE: To determine the etiology of Pseudomonas aeruginosa surgical-site infections following cardiac surgery. SETTING: University teaching hospital. PATIENTS: Those with wound cultures that grew P. aeruginosa after cardiac surgery performed from 1999 to 2001. METHODS: Medical records and operating room (OR) records of patients with P. aeruginosa cardiac surgical-site infections from 1999 to 2001 were reviewed. Healthcare workers involved with two or more cases were interviewed and examined. Specimens for environmental cultures were obtained from the ORs and cardiac surgical equipment. Cardiac surgery cases were observed and postoperative care and the cleaning of surgical instruments were investigated. OR air handling system records during the epidemic period were reviewed. Molecular fingerprinting of available P. aeruginosa isolates from infected patients and a healthcare worker was done. RESULTS: There were five P. aeruginosa cardiac surgical-site infections from January to August 2001, compared with no such infections from 1999 to 2000. All were adult patients. One cardiac surgeon with onychomycosis operated on all five cases. He did not routinely double glove. The involved fingernail grew P. aeruginosa. Three P. aeruginosa patient isolates were available for pulsed-field gel electrophoresis; two were identical to the isolate from the involved surgeon's onychomycotic nail. No environmental OR cultures grew P. aeruginosa. The surgeon's culture-positive nail was completely removed. There have been no P. aeruginosa surgical-site infections among cardiac surgery patients since this intervention. CONCLUSION: At least two cases of a cluster of P. aeruginosa surgical-site infections resulted from colonization of a cardiac surgeon's onychomycotic nail.     

Co-carriage rates of vancomycin-resistant Enterococcus and extended-spectrum beta-lactamase-producing bacteria among a cohort of intensive care unit patients: implications for an active surveillance program.

OBJECTIVE: To assess the co-colonization rates of extended-spectrum beta-lactamase (ESBL)-producing bacteria and vancomycin-resistant Enterococcus (VRE) obtained on active surveillance cultures. DESIGN: Prospective cohort study. SETTING: Medical and surgical intensive care units (ICUs) of a tertiary-care hospital. PATIENTS: Patients admitted between September 2001 and November 2002 to the medical and surgical ICUs at the University of Maryland Medical System had active surveillance perirectal cultures performed. Samples were concurrently processed for VRE and ESBL-producing bacteria. RESULTS: Of 1,362 patients who had active surveillance cultures on admission, 136 (10%) were colonized with VRE. Among these, 15 (positive predictive value, 11%) were co-colonized with ESBL. Among the 1,226 who were VRE negative, 1,209 were also ESBL negative (negative predictive value, 99%). Among the 1,362 who had active surveillance cultures on admission, 32 (2%) were colonized with ESBL. Among these, 15 (47%) were co-colonized with VRE. Of the 32 patients colonized with ESBL, 10 (31%) had positive clinical cultures for ESBL on the same hospital admission. For these 10 patients, the surveillance cultures were positive an average of 2.7 days earlier than the clinical cultures. CONCLUSIONS: Patients who are colonized with VRE can also be co-colonized with other antibiotic-resistant bacteria such as ESBL-producing bacteria. Our study is the first to measure co-colonization rates of VRE and ESBL-producing bacteria. Isolating VRE-colonized patients would isolate 47% of the ESBL-colonized patients without the need for further testing. Hence, active surveillance for VRE should also theoretically diminish the amount of patient-to-patient transmission of ESBL-producing bacteria.     

Outbreak of Corynebacterium pseudodiphtheriticum Infection in Cystic Fibrosis Patients, France

An increasing body of evidence indicates that nondiphtheria corynebacteria may be responsible for respiratory tract infections. We report an outbreak of Corynebacterium pseudodiphtheriticum infection in children with cystic fibrosis (CF). To identify 18 C. pseudodiphtheriticum strains isolated from 13 French children with CF, we used molecular methods (partial rpoB gene sequencing) and matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry. Clinical symptoms were exhibited by 10 children (76.9%), including cough, rhinitis, and lung exacerbations. The results of MALDI-TOF identification matched perfectly with those obtained from molecular identification. Retrospective analysis of sputum specimens by using specific real-time PCR showed that ≈20% of children with CF were colonized with these bacteria, whereas children who did not have CF had negative test results. Our study reemphasizes the conclusion that correctly identifying bacteria at the species level facilitates detection of an outbreak of new or emerging infections in humans.     

Pseudomonas aeruginosa and Surfactant-associated Proteins A and D

Surfactant-associated proteins A and D (SP-A and SP-D) are two pulmonary collectins that bind to bacterial, fungal and viral pathogens and have multiples classes of receptors on pneumocyte and macrophage membrane. They are chemoattractant for phagocytes, enhance uptake and killing of bacteria by macrophages and neutrophils. These molecules also act as activation ligand on macrophages and neutrophils to enhance phagocytosis, resulting in an increased bacterial clearance. Depending on activation of cells by stimuli, SP-A and SP-D modulate production of antimicrobial free radicals by phagocytes and secretion of cytokines. In vivo, SP-A deficient mice infected with Pseudomonas aeruginosa (P. aeruginosa) have decreased bacterial clearance and exacerbated inflammatory response in the lungs. Serious alterations in macrophages and increased production of reactive oxygen species were found in non-infected SP-D deficient mice. Patients with cystic fibrosis are frequently colonized by P. aeruginosa. Decreased levels of SP-A and SP-D have been measured in bronchoalveolar lavage fluid of these patients, as well as patients with acute pneumonia but no chronic lung disease. P. aeruginosa secretes various proteases, among them, elastase and protease IV have been found to degrade SP-A and SP-D and abrogate their immune function. However, further investigations are necessary to examine whether these deficiencies facilitate P. aeruginosa infections or stand as consequences.     

Recombinant OprF-OprI as a vaccine against Pseudomonas aeruginosa infections

A vaccine against Pseudomonas aeruginosa based on recombinant outer membranes has been developed. After intramuscularly injecting into patients with severe burns, antibodies against P. aeruginosa were induced. Vaccination was well tolerated. Intranasal application of the vaccine into volunteers, induced specific s-IgA antibodies. We conclude that the newly developed vaccine may be suitable for protection of the main risk groups of P. aeruginosa infections. In particular, for the protection of burn patients and patients with cystic fibrosis.     

急诊重症监护病房患者下呼吸道感染铜绿假单胞菌的研究

目的探讨急诊重症监护病房(EICU)下呼吸道感染患者铜绿假单胞菌分布特征及其耐药性。方法对2005年8月~2006年2月间,在医院EICU收治的25例下呼吸道感染患者的临床资料进行分析。结果在EICU的25例下呼吸道感染患者中,共分离出病原菌81株,革兰阳性菌32.1%,革兰阴性菌43.2%,真菌24.7%;其中铜绿假单胞菌占13.6%;铜绿假单胞菌药敏结果表明头孢噻肟、庆大霉素、复方新诺明、米诺环素、左氧氟沙星、加替沙星等抗菌药物耐药。结论铜绿假单胞菌感染与耐药是EICU中下呼吸道感染患者治疗中的重要问题,应引起重视。