Legionella Australia

BACKGROUND: Two proven nosocomial cases of Legionella pneumonia occurred at the Wesley Hospital (Brisbane, Australia) in May 2013. To trace the epidemiology of these cases, whole genome sequence analysis was performed on Legionella pneumophila isolates from the infected patients, prospective isolates collected from the hospital water distribution system (WDS), and retrospective patient isolates available from the Wesley Hospital and other local hospitals. METHODS: Legionella pneumophila serogroup 1 isolates were cultured from patient sputum (n = 3), endobronchial washings (n = 3), pleural fluid (n = 1), and the Wesley Hospital WDS (n = 39)...

Legionellosis is an important public health problem in the United States and other countries, and residents of long-term care facilities (LTCFs) are at higher risk for Legionnaires' disease than the general population. In this study, we reviewed published US and international guidelines for the primary prevention of legionellosis in LTCFs, including nursing homes, skilled nursing facilities, assisted living facilities, and aged care facilities. The results of this review indicate that most guidelines emphasize adequate design and maintenance of water systems and water temperatures; however, guidance regarding routine preventative environmental testing for Legionella bacteria is not uniform among various jurisdictions, and facilities are generally left without clear guidance on this issue...

Water reuse has become increasingly important for sustainable water management. Currently, its application is primarily constrained by the potential health risks. Presently there is limited knowledge regarding the presence and fate of opportunistic pathogens along reuse water distribution pipelines. In this study opportunistic human pathogens Legionella spp., L. pneumophila and Mycobacterium avium complex were detected using real-time polymerase chain reaction along two South Australian reuse water distribution pipelines at maximum concentrations of 10⁵, 10³ and 10⁵ copies/mL, respectively...

Legionella pneumophila is the main pathogen responsible for outbreaks of Legionnaires' disease, which can be related to contaminated water supplies such as cooling towers or water pipes. We combined conventional molecular methods and whole genome sequence (WGS) analysis to investigate an outbreak of L. pneumophila in a large Australian hospital. Typing of these isolates using sequence-based typing and virulence gene profiling, was unable to discriminate between outbreak and non-outbreak isolates. WGS analysis was performed on isolates during the outbreak, as well as on unlinked isolates from the Public Health Microbiology reference collection...

In this study, quantitative PCR (qPCR) was used for the detection of four opportunistic bacterial pathogens in water samples collected from 72 rainwater tanks in Southeast Queensland, Australia. Tank water samples were also tested for fecal indicator bacteria (Escherichia coli and Enterococcus spp.) using culture-based methods. Among the 72 tank water samples tested, 74% and 94% samples contained E. coli and Enterococcus spp., respectively, and the numbers of E. coli and Enterococcus spp. in tank water samples ranged from 0...

The harvesting of rainwater is gaining acceptance among many governmental authorities in countries such as Australia, Germany, and South Africa, among others. However, conflicting reports on the microbial quality of harvested rainwater have been published. To monitor the presence of potential pathogenic bacteria during high-rainfall periods, rainwater from 29 rainwater tanks was sampled on four occasions (during June and August 2012) in a sustainable housing project in Kleinmond, South Africa. This resulted in the collection of 116 harvested rainwater samples in total throughout the sampling period...

Legionella species are intracellular gram-negative bacilli that require specific culture media for growth. Transplant recipients with impaired cellular immunity are at particular risk for infection with this pathogen. Most human disease is caused by Legionella pneumophila; disease caused by non-L. pneumophila species is reported mainly in immunosuppressed patients with the exception of Legionella longbeachae. L. longbeachae is a common cause of Legionnaires' disease in Australia and New Zealand, and is associated with exposure to potting soil...

Legionella species are a common cause of community-acquired pneumonia, infrequently complicated by cavitary disease. We describe Legionella pneumophila pneumonia and abscess formation in an immunosuppressed patient receiving corticosteroid therapy for metastatic breast carcinoma. The predisposing role of corticosteroids is discussed and the management of this complication is reviewed.

We assessed the comparative efficacy of empirical therapy with beta-lactam plus macrolide vs. beta-lactam plus doxycycline for the treatment of community-acquired pneumonia (CAP) among patients in the Australian Community-Acquired Pneumonia Study. Both regimens demonstrated similar outcomes against CAP due to either 'atypical' (Chlamydophila, Legionella or Mycoplasma spp.) or typical bacterial pathogens.

Legionella-like bacteria were isolated from the respiratory tract of two patients in California, USA, and South Australia, but were not thought to cause disease. These bacteria, strains F2632 and IMVS-3376(T), were found to have identical Legionella macrophage infectivity potentiator (mip) gene sequences and were therefore further characterized to determine their genetic and phenotypic relatedness and properties. Both of these Gram-negative-staining bacterial strains grew on buffered charcoal yeast extract medium, were cysteine auxotrophs and made a characteristic diffusible bright yellow fluorescent pigment, with one strain making a late appearing colony-bound blue-white fluorescent pigment...

Reported cases of legionellosis attributable to Legionella longbeachae infection have increased worldwide. In Australia and New Zealand, L. longbeachae has been a known cause of legionellosis since the late 1980s. All cases for which a source was confirmed were associated with potting mixes and composts. Unlike the situation with other Legionella spp., L. longbeachae-contaminated water systems in the built environment that cause disease have not been reported. Spatially and temporally linked outbreaks of legionellosis associated with this organism also have not been reported...

A novel Legionella species was identified based on analysis of 16S rRNA and mip (macrophage infectivity potentiator) gene sequences, cellular fatty acids, isoprenoid quinones, biochemical reactions, antigens and quantitative DNA-DNA hybridization. Strain CDC-1796-JAP-E(T) was isolated from well water at the Nagasaki Municipal Medical Center, Japan. Two strains, CDC-3041-AUS-E and CDC-3558-AUS-E, were isolated from water samples during an outbreak of legionellosis in South Australia. Strain CDC-5427-OH-H was isolated from a 66-year-old female patient diagnosed with Legionnaires' disease in the US...

A total of 214 rainwater samples from 82 tanks were collected in urban Southeast Queensland (SEQ) in Australia and analyzed for the presence and numbers of zoonotic bacterial and protozoal pathogens using binary PCR and quantitative PCR (qPCR). Quantitative microbial risk assessment (QMRA) analysis was used to quantify the risk of infection associated with the exposure to potential pathogens from roof-harvested rainwater used as potable or nonpotable water. Of the 214 samples tested, 10.7%, 9.8%, 5.6%, and 0...

The study aimed to evaluate the suitability of Escherichia coli, enterococci, and Clostridium perfringens for assessing the microbiological quality of roof-harvested rainwater and assessing whether the concentrations of these faecal indicators can be used to predict the presence or absence of specific zoonotic bacterial or protozoan pathogens. From a total of 100 samples tested, 58%, 83%, and 46% of samples were found to be positive for, respectively, E. coli, enterococci, and Clostridium perfringens spores, as determined by traditional culture-based methods...

Legionella longbeachae causes most cases of legionellosis in Australia and may be underreported worldwide due to the lack of L. longbeachae-specific diagnostic tests. L. longbeachae displays distinctive differences in intracellular trafficking, caspase 1 activation, and infection in mouse models compared to Legionella pneumophila, yet these two species have indistinguishable clinical presentations in humans. Unlike other legionellae, which inhabit freshwater systems, L. longbeachae is found predominantly in moist soil...

Legionella infection is an important cause of community-acquired pneumonia in Australia. Morbidity and mortality is significant. Diagnosis remains a challenge with infection often unrecognised, particularly early in the course of illness. An understanding of available diagnostic methods and their limitations is important to public health practitioners and clinicians alike.

Legionella spp. are pathogens that can cause Legionnaires' disease in humans through inhalation of contaminated aerosols. The principal reservoir for these microorganisms is water, but Legionella spp. have been isolated from composted vegetable and plant material, and from many potting mixes as well. In Australia, there have been several cases of Legionnaires' disease in which Legionella longbeachae has been isolated from potting soils. In Switzerland, the source of infection cannot always be identified as water or cooling towers: therefore, we have investigated 46 commercially available potting soils in Switzerland to determine the presence of Legionella spp...

BACKGROUND: Community acquired pneumonia is a common condition presenting to general practitioners and emergency departments across Australia. Legionella is one of many pathogens responsible for community acquired pneumonia. Cases of Legionella may occur sporadically or as part of an outbreak. OBJECTIVE: This article describes the clinical manifestations of Legionella infection and provides clinicians with an approach to its diagnosis and management. DISCUSSION: Legionella infection is typically associated with community acquired pneumonia, which can be severe...

In this study, the microbiological quality of roof-harvested rainwater was assessed by monitoring the concentrations of Escherichia coli, enterococci, Clostridium perfringens, and Bacteroides spp. in rainwater obtained from tanks in Southeast Queensland, Australia. Samples were also tested using real-time PCR (with SYBR Green I dye) for the presence of potential pathogenic microorganisms. Of the 27 rainwater samples tested, 17 (63%), 21 (78%), 13 (48%), and 24 (89%) were positive for E. coli, enterococci, C...

BACKGROUND AND OBJECTIVE: To investigate the association between serological evidence of past infections with common respiratory pathogens and lung function in members of an isolated community of Aborigines from tropical coastal north-western Australia. METHODS: FEV(1) and FVC were assessed by dry bellows spirometer. Serum IgG titres to 11 common respiratory pathogens were assayed. Smoking history was assessed by questionnaire. Reciprocal positive IgG titres were taken as >or=10 for all pathogens with the exception of Legionella spp...