Pneumophila Serotype Research Articles

A PLEURAL PLAQUE, MULTIFOCAL CONSOLIDATIONS, AND MARKEDLY ELEVATED INFLAMMATORY MARKERS HINT AT THE ATYPICAL: A CASE OF ARDS AND SEPTIC SHOCK SECONDARY TO LEGIONELLA PNEUMOPHILA

TYPE: Case Report TOPIC: Chest Infections INTRODUCTION: Legionella pneumophila (LP) is a common cause of community acquired pneumonia (CAP) and particular diagnostics may be predictive of this atypical infection. CASE PRESENTATION: An 83 year old female with no medical history presented with dyspnea, cough, and fevers. Her oxygen saturation on 6 liters nasal cannula was 88%. Notable labs included a WBC 14.60 k/uL, C-reactive protein 41.2 mg/dL, Procalcitonin 42.06 ng/mL. A CT pulmonary angiogram showed multifocal consolidations and a calcified pleural plaque on the right. She was placed on high flow nasal cannula, infectious workup was sent, and she was started on vancomycin, cefepime, and azithromycin. Her arterial blood gas revealed pH 7.37, PaCO2 38, PaO2 58 on 50% FiO2. On day 2, she was intubated and transferred to the ICU for ARDS and septic shock. With a positive urine antigen for Legionella pneumophila serotype 1, she was switched to levofloxacin. She was weaned off pressors and extubated after 4 days. DISCUSSION: There is increasing incidence of severe legionella infection in the United States requiring ICU admission. Identification is unavailable early in the workup often prompting broad empiric coverage. The use of C-reactive protein and procalcitonin have been studied regarding their diagnostic and prognostic value in CAP. Furthermore, the finding of a pleural plaque in our patient informed on an exposure history that raised the suspicion of an atypical process. CONCLUSIONS: With regard to the management of CAP, there is diagnostic value of inflammatory markers paired with unusual radiographic findings to suggest an atypical pneumonia like LP. DISCLOSURE: Nothing to declare. KEYWORD: Legionella pneumophila

Legionnaires\u2019 disease arising with hirsutism: case report of an extremely confusing event

BackgroundLegionella bacteria is a common cause of pneumonia, but the infection may affect several organs in the most serious cases. A systemic involvement ab initio could be non-specific, leading to a diagnostic misinterpretation.Case presentationA 33-year-old woman had been complaining of mental confusion, restlessness, aggressiveness, and, subsequently, hirsutism. After 3 weeks, the patient developed pneumonia and died during the hospitalization. The autopsy examination revealed a multi-organ necrotizing exudative disease involving the lung, the heart and the brain. The microbiological tests of tracheal aspirate were positive for Legionella pneumophila serotype 1.ConclusionThe Legionella infection may show a proteiform clinical course and an extra-pulmonary manifestation may be the first sign of the disease. Herein, we report a case of Legionella infection in a young female, presenting with non-specific neurological symptoms and hirsutism at onset, misdiagnosed as a metabolic disease.

Cytotoxicity, Intracellular Replication, and Contact-Dependent Pore Formation of Genotyped Environmental Legionella pneumophila Isolates from Hospital Water Systems in the West Bank, Palestine.

Legionella pneumophila is the causative agent of Legionnaires’ disease. Due to the hot climate and intermittent water supply, the West Bank, Palestine, can be considered a high-risk area for this often fatal atypical pneumonia. L. pneumophila occurs in biofilms of natural and man-made freshwater environments, where it infects and replicates intracellularly within protozoa. To correlate the genetic diversity of the bacteria in the environment with their virulence properties for protozoan and mammalian host cells, 60 genotyped isolates from hospital water systems in the West Bank were analyzed. The L. pneumophila isolates were previously genotyped by high resolution Multi Locus Variable Number of Tandem Repeat Analysis (MLVA-8(12)) and sorted according to their relationship in clonal complexes (VACC). Strains of relevant genotypes and VACCs were compared according to their capacity to infect Acanthamoeba castellanii and THP-1 macrophages, and to mediate pore-forming cytotoxicity in sheep red blood cells (sRBCs). Based on a previous detailed analysis of the biogeographic distribution and abundance of the MLVA-8(12)-genotypes, the focus of the study was on the most abundant L. pneumophila- genotypes Gt4(17), Gt6 (18) and Gt10(93) and the four relevant clonal complexes [VACC1, VACC2, VACC5 and VACC11]. The highly abundant genotypes Gt4(17) and Gt6(18) are affiliated with VACC1 and sequence type (ST)1 (comprising L. pneumophila str. Paris), and displayed seroroup (Sg)1. Isolates of these two genotypes exhibited significantly higher virulence potentials compared to other genotypes and clonal complexes in the West Bank. Endemic for the West Bank was the clonal complex VACC11 (affiliated with ST461) represented by three relevant genotypes that all displayed Sg6. These genotypes unique for the West Bank showed a lower infectivity and cytotoxicity compared to all other clonal complexes and their affiliated genotypes. Interestingly, the L. pneumophila serotypes ST1 and ST461 were previously identified by in situ-sequence based typing (SBT) as main causative agents of Legionnaires’ disease (LD) in the West Bank at a comparable level. Overall, this study demonstrates the site-specific regional diversity of L. pneumophila genotypes in the West Bank and suggests that a combination of MLVA, cellular infection assays and hierarchical agglomerative cluster analysis allows an improved genotype-based risk assessment.

Epidemic of Legionella Pneumophila Pneumonia South of Brescia (Italy)

In September 2018, a serious epidemic of Legionella Pneumophila serotypes 1-2-14, diagnosed by the Istituto Superiore Sanita (ISS), occurred in the low plain south of Brescia. This resulted in a considerable number of hospitalizations in the hospitals of the ATS of Brescia and Valpadana (Mantua) with high mortality rate. It was an anomalous situation both for the spread and for the Legionella serotypes which alarmed the Istituto Superiore Sanita and the local health structures. This epidemic is an expressions of the malaise of the geographical area in question caused by the impact of various environmental degradations. Some environmental criticalities: 1-the low water flow of the Chiese river in the summer of 2018 due to the exploitation of water by intensive agriculture and the presence of 22 hydroelectric power plants along its course. 2-the presence of numerous industrial cooling towers with a lack of mapping of the same towers by the political bodies (Region and Municipalities). 3-the abnormal disposal of sludge on the countryside surrounding the agricultural area adjacent to the river bed of the Chiese river as a consequence of the enormous production of livestock waste by pig, cattle and chicken farms in the same area. 4-In the lower Brescia plain there are numerous disposal companies that receive sewage sludge from 15 regions of Italy and also from abroad. 5-different and numerous types of landfills in the municipalities of Montichiari, Rezzato, Ghedi, Calcinato and Bedizzole filled with 12 million cubic meters of toxic-harmful waste. 6- the Lombardy region allows an excessive number of CERs (Catalog European Waste). It concludes by emphasizing how everyone, citizens and institutions, have a great responsibility in the management of the territory and a change of direction is hoped for an economy that has reached limits that it can no longer tolerate. This calls the various responsibilities of Politics, Public Health, the industrial and agricultural world in the management of a territory that continues to send signs of suffering and which is reflected on the health of men, animals and the plant world.

642. Trends and cost burden of Legionella urine antigen test

Background Legionella urine antigen (LUAg) testing is used to identify the pathogen Legionella pneumophila serotype 1 which accounts for 50 to 70% of Legionella pneumonia and has 80% sensitivity and 95% specificity. The 2019 ATS/IDSA CAP guidelines recommend against routinely testing urine for LUAg except when indicated by epidemiological factors or severe cases of CAP; however, the recommendation is based on a low quality of evidence. In 2014 & 2015 there were 32 and 39 cases, respectively in the state of Mississippi. The purpose of this study was to evaluate the trends of ordering LUAg, positive results and estimate the cost burden at the University of Mississippi Medical Center (UMMC).MethodsWe performed a retrospective study of all patients who received the LUAg test at UMMC from January 3, 2013 to December 31, 2019. Patient Cohort Explorer was used to obtain de-identified patient data from EPIC. We obtained the number of encounters and patients on whom the LUAg test was performed during their inpatient hospitalization. Coding and billing offices provided the cost per LUAg test.ResultsLUAg test was ordered 2,642 times on 2350 patients between 2013 and 2019. 22 LUAg test results were positive in 21 patients. 2,627 tests were done on patients admitted in the hospital. Of the 1,181 tests ordered in female patients, 11 were positive and of the 1461 tests done in male patients, 11 were positive. The minimum age for ordered test was under 1 year while the oldest patient is 89 years old with a median age of 57 years. The youngest patient to be positive is 21 and the oldest patient was 72 years. 1,471 tests were done in African American patients and 1084 tests in Caucasian patients. At the end of study period 1901 were alive and 741 deceased. The median length of stay for the patient receiving the test was 7 days with 1726 patients discharged within 10 days. 174, 255, 301, 433, 467, 395, 613 tests were ordered respectively from 2013 to 2019. At self pay cost of $132.82 in 2019 USD, the total cost of 2642 tests was $350,910.44. About $15,950.47 was spent for each positive LUAg test during the study period.ConclusionIncidence of pneumonia from Legionella in Mississippi is low. Based on our study, we recommend to follow the current ATS/IDSA guidelines and order the test in select patients as recommended, in efforts to reduce diagnostic costs.Disclosures All Authors: No reported disclosures

A Hospital-based Study on the Local Epidemiology of Pneumonia Including the Contribution of Legionella Pneumonia.

BackgroundIn real-life practice, only 20% of hospitalised pneumonia cases have an identified etiology. The usage of Legionella urine antigen test (LUAT) in developed nations revolutionised case detection rates. Accordingly, our objectives were to study the microbiological etiology for hospitalised pneumonia patients and the diagnosis of Legionella pneumonia.MethodsA prospective, observational single-centre study was conducted where all 504 cases that were consecutively admitted for pneumonia were enrolled. Blood and sputum samples obtained were used to identify pathogens using standard microbiological culture methods. The urine samples collected were tested using the ImmunocatchTM Legionella immunochromatographic (ICT) urine antigen test.ResultsA microbiological diagnosis was only achieved in 104 cases (20.6%) and a Gram-negative infection predominance was observed. Culture-positive cases required longer hospitalisation (8.46 days versus 5.53 days; P < 0.001) and the higher usage of antipseudomonal antibiotics (23.1% versus 8.3%; P < 0.001). Only 3 cases (0.6%) were diagnosed with Legionella pneumonia.ConclusionThe local pathogen distribution is diverse compared to other regions. Culture-negative pneumonia is common and significantly differs from culture-positive pneumonia. Legionella pneumophila serotype 1 is not a common cause of pneumonia and LUAT did not help demystify the cause of culture-negative pneumonia.

Isolation and identification of Legionella spp. from hot spring water in Algeria by culture and molecular methods.

Due to infectious risk associated with the presence of Legionella in warm water, we determined the prevalence of living Legionella spp. in hot spring water in Algeria. Detection of Legionella by culture was done by using two methods, direct culture on agar plates and co-culture with amoeba. Fifty samples were taken from different hot springs in northern Algeria, including swimming pools, showers and thermal sources. Legionella pneumophila serotypes were predominant, accounting for 60% of positive samples. Direct method allowed the isolation of 13 L. pneumophila only of 50 samples (26%), whereas co-culture using a panel of three free living amoeba allowed the isolation of 119 Legionella species from the same samples (80%) CONCLUSIONS: Amoeba co-culture allowed the isolation of several Legionella sp., while direct culture allowed the isolation of L. pneumophila only. Remarkably, Legionella longbeachae, usually isolated from soil and compost, was isolated for the first time in thermal water in three samples using Vermamoeba vermiformis co-culture. The presence of Legionella in the water of hot springs in Algeria, which are mainly frequented by individuals at risk of Legionellosis, requires urgent control measures.

Occurrence of Legionella in Nonpotable Reclaimed Water

Legionella was monitored in reclaimed water systems and were detected by culture in 50% of 115 samples, while 80% of the samples were positive by quantitative polymerase chain reaction (qPCR). The lowest level of Legionella was in a system that practiced biological nutrient removal and maintained an average 0.3 mg/L free chlorine residual. The difference between qPCR and ethidium monoazide treated samples was used as an indicator of viability, and the greatest difference was in a chloraminated system, where the molecular method indicated a 9% viability. Ninety‐six percent of the species were L. pneumophila, and 87% were identified as L. pneumophila serotype 1. Total amoebae (summed as cysts or trophozoites) were detected in 100% of samples from all six systems, and were mostly (50–95%) in the active trophozoite phase. In the chloraminated system, 87% of the mesophilic amoebae and 66% of the thermophilic amoebae were in the cyst phase.

Distribution and Genetic Diversity of Legionella pneumophila Serotype in Kuwait Environment

Background: Legionella pneumophila is a waterborne organism that is increasingly recognized to cause community acquired and nosocomial pneumonia in humans. Domestic water systems have often been implicated as the source in outbreaks of Legionnaires’ disease. Legionella can survive under various conditions in various water sources and acquired antibiotic resistance to many routinely prescribed antibiotics. Routine monitoring of environmental water for Legionella species is proving helpful in reducing disease outbreak. Methods: A total of 260 of Legionella pneumophila isolates were isolated from environmental water sources from building facilities in Kuwait. The genetic diversity of the 102 isolates were analysis by the SBT method according to the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Study Group for Legionella. The distribution of Legionella isolates was investigated according to geographical region. Results: The Legionella isolates were discriminated into 11 distinct SBT profiles, of which six (ST1223, ST1436, ST1555, ST1604, ST1718, and ST1719) were new to the ESGLI SBT database. L. pneumophila sg 7 was distributed broadly through Kuwait, accounting for 38.2% of the isolates and predominated in cooling towers water with unique sequence type to Kuwait. The second most dominant strain L. pneumophila sg 3 (32.4%), predominated in the bathroom. L. pneumophila sg 1 (18.3%), L. pneumophila sg 10 (6.9%), and L. pneumophila sg 4 (3.9%), predominated in the cooling towers. In SBT analysis, L. pneumophila sg 7 isolates were differentiated into 2 sequence types (STs), ST1718 (37.3 %) is the dominant ST in cooling tower. The unique allelic profile of ST1718, obtained from the cooling tower, was not found in the ESGLI SBT database. Conclusions: The findings of this study highlight the importance of understanding the epidemiology and ecology of L. pneumophila from public facilities in terms of public health. Furthermore, provide useful information for future epidemiological investigation of local and regional outbreaks of Legionnaires’ disease.

Legionella Surveillance in a VA Hospital Water System: Cold Water Sampling Is More Sensitive, But Hot Water Samples are More Likely to Yield Legionella pneumophila Serotype 1 (Lp 1)

Legionella Surveillance in a VA Hospital Water System: Cold Water Sampling Is More Sensitive, But Hot Water Samples are More Likely to Yield Legionella pneumophila Serotype 1 (Lp 1)

Infecciones por Legionella

Legionella is an intracellular gram-negative bacillus, one of the main causes of communityacquired pneumonia and nosocomial pneumonia. It is an environmental bacterium whose natural habitat is freshwater rivers and lakes. The main mechanism responsible for its spread is the ambient air and inhalation of aerosolized water through cooling towers, ventilation ducts etc. The clinical picture is variable, with pneumonia as clinically freceuente caused by Legionella pneumophila. Culture of respiratory secretions and detection of Legionella pneumophila serotype 1 in urine are the most specific diagnostic tests. In the treatment of Legionella infection is recommended quinolones and macrolides. A prolonged treatment is used in immunocompromised patients or severe extrapulmonary involvement.

The Effect of Aeromonas spp. on the Growth of Legionella pneumophila in vitro

This study was designed to determining the ability of six Aeromonas spp. isolated from different water sources (sanitation plants, water distribution systems, and Reverse Osmosis water) to inhibit the growth of Legionella pneumophila serotype 1 -15, from the same sources, in vitro. Eighteen isolates of 6 Aeromonas spp. were tested for their ability to inhibiting the growth of six isolates of L. pneumophila serotype1-15.The interactions between L. pneumophila and Aeromonas spp. were investigated by using cells from broth culture and as solid culture and cell-free supernatants (CFSs) of the latter on the growth of the former on the LAB medium. Results showed that A. schubertii, A. encheleia and A. hydrophila supernatant, cells and solid cultures have the ability to inhibiting the growth of L. pneumophila serotypes 1 and 2-15. While all tested Aeromonas spp. inhibited both L. pneumophila serotypes, when directly inoculated or transferred as ready grown solid culture. The results indicated that growth and multiplication of L. pneumophila could be inhibited by other bacteria sharing the same habitat and the level of this effect varies among the species. The presence of Aeromonas spp. and L. pneumophila in drinking water can be an important threat to public health, thus greater awareness of these bacteria as potential enteropathogens is warranted.

Legionella pneumophilaSerotype 1 Pneumonia in Patient Receiving Adalimumab

We describe a case of severe pneumonia caused by Legionella pneumophila serotype 1 in a woman receiving the tumor necrosis factor–α antagonist to treat rheumatoid arthritis. As use of tumor necrosis factor–α inhibitors increase, clinicians should consider their possible association with legionellosis.

Isolation and identification of Legionella pneumophila from material reclamation facilities

Sampling points at a material reclamation facility (MRF) were monitored over three months for the presence of Legionella spp. A number of different Legionellae were isolated and typed to identify L. pneumophila serogroup 1, the serotype which is the most common human pathogen. Phenotypic methods resulted in a total of 61 presumptive isolates of Legionella spp. Using latex agglutination, 26 out of the 61 were identified as L. pneumophila serogroup 1, 23 as L. pneumophila serogroups 2–14, and the remaining 12 were Legionella spp. However, on typing using pulse field gel electrophoresis, the 26 L. pneumophila serotype 1 isolates were a diverse group of 25 PFGE types with none persisting in the environment over time. This diversity suggests that there are a number of contamination sources for this important human pathogen in the MRF environment which constitute a risk to health for operatives in these facilities.

Resistance of Legionella pneumophila serotype 1 biofilms to chlorine-based disinfection

The presence of Legionella spp. in potable water systems is a major concern to municipal water providers and consumers alike. Despite the inclusion of chlorine in potable supplies and frequent chlorination cycles, the bacterium is a recalcitrant human pathogen capable of causing incidents of Legionnaires' disease, Pontiac fever and community-acquired pneumonia in humans. Using two materials routinely employed for the delivery of potable water as a substratum, copper and stainless steel, the development of Legionella pneumophila biofilms and their response to chlorination was monitored over a three-day and a three-month period, respectively. Preliminary in vitro studies using broth and sterile tap water as culture media indicated that the bacterium was capable of surviving in low numbers for 28 days in the presence of chlorine. Subsequently, biofilms were grown for three days, one month and two months, respectively, on stainless steel and copper sections, which are widely used for the conveyance of potable water. Immediately after exposure to 50mg/L chlorine for 1h, the biofilms yielded no recoverable colonies, but colonies did reappear in low numbers over the following days. Despite chlorination at 50mg/L for 1h, both one- and two-month-old L. pneumophila biofilms were able to survive this treatment and to continue to grow, ultimately exceeding 1x10(6)cfu per disc. This research provides an insight into the resistance afforded to L. pneumophila against high levels of chlorine by the formation of biofilms and has implications for the delivery of potable water.

Survey of pathogenic free-living amoebae and Legionella spp. in mud spring recreation area

Acanthamoeba, Hartmannella, and Naegleria are free-living amoebae, ubiquitous in aquatic environments. Several species within these genera are recognized as potential human pathogens. These free-living amoebae may facilitate the proliferation of their parasitical bacteria, such as Legionella. In this study, we identified Acanthamoeba, Hartmannella, Naegleria, and Legionella using various analytical procedures and investigated their occurrence at a mud spring recreation area in Taiwan. We investigated factors potentially associated with the prevalence of the pathogens, including various water types, and physical and microbiological water quality parameters. Spring water was collected from 34 sites and Acanthamoeba, Hartmannella, Naegleria, and Legionella were detected in 8.8%, 35.3%, 14.7%, and 47.1%, respectively. The identified species of Acanthamoeba included Acanthamoeba castellanii and Acanthamoeba polyphaga. Nearly all the Hartmannella isolates are identified as Hartmannella vermiformis. The Naegleria species included Naegleria australiensis and its sister groups, and two other isolates referred to a new clade of Naegleria genotypes. The Legionella species identified included unnamed Legionella genotypes, Legionella pneumophila serotype 6, uncultured Legionella spp., Legionella lytica, Legionella drancourtii, and Legionella waltersii. Significant differences (Mann–Whitney U test, P < 0.05) were observed between the presence/absence of Hartmannella and total coliforms, between the presence/absence of Naegleria and heterotrophic plate counts, and between the presence/absence of Legionella and heterotrophic plate counts. This survey confirms that pathogenic free-living amoebae and Legionella are prevalent in this Taiwanese mud spring recreation area. The presence of pathogens should be considered a potential health threat when associated with human activities in spring water.

Identification of 18S ribosomal DNA genotype of Acanthamoeba from hot spring recreation areas in the central range, Taiwan

Acanthamoeba is a free-living amoebae ubiquitous to aquatic environments. Within the genus a few species are recognized as opportunistic potential human pathogens, which cause granulomatous amoebic encephalitis (GAE) and keratitis. Infections of keratitis are frequently reported through wearing lens while swimming in the non-disinfected aquatic environment. Contaminations in hot tubs, spas and public baths are also possible. As a result, in this study, we identified Acanthamoeba based on the PCR amplification with a genus-specific primer pair and investigated the distribution of Acanthamoeba at five hot spring recreation areas in central range, Taiwan. We gathered data on factors potentially associated with the pathogen's distribution, including various sampling sites, aquatic environment, physical and microbiological water quality parameters. Spring water was collected from 55 sites and Acanthamoeba was detected in 9 (16.4%). The most frequently detected was Acanthamoeba griffini, followed by Acanthamoeba jacobsi Legionella were detected in 18 (32.7%) of the sites sampled in this study. The species of Legionella identified included Legionella pneumophila serotype 6, serotype 1, and Legionella erythra. Overall, 9.1% of the samples contained both Acanthamoeba and Legionella. The prevalence of Acanthamoeba was contrary to the levels of microbiological indicators recommended by Taiwan CDC, and no significant differences (Mann-Whitney U test, P<0.05) were observed between the presence/absence of Acanthamoeba and water quality parameters. Results of this survey confirm the existence of Acanthamoeba in Taiwan spring recreation areas. Acanthamoeba, the organism responsible for the majority of Acanthamoeba keratitis and can serve as vehicles for facultative pathogens, should be considered a potential threat for health associated with human activities in spring recreation areas of Taiwan.

Influence of temperature on growth of Legionella pneumophila biofilm determined by precise temperature gradient incubator

Bacterial growth is influenced by several different culture conditions. Temperature is one of an essential component which regulates bacterial growth and their morphology. The influence of temperature on the length of bacteria was investigated in broth and on agar in a temperature range from 30.0 degrees C to 47.0 degrees C in 0.5 degrees C steps using a newly developed temperature gradient incubator. The incubator is able to reach a set temperature within 2 h and maintain temperature as accurate as +/-0.1 degrees C of the set temperature. Three Legionella pneumophila serotype 1 strains were incubated for 48 h in BCYE-alpha agar at various temperatures ranging from 30.0 degrees C to 48.0 degrees C and length of bacteria grown at each temperature was microscopically measured. Ability of bacteria to multiply at a given temperature was also determined. L. pneumophila serotype 1 strains ATCC 33152, a clinical isolate Okinawa 02-001 were going to elongate to longer than 100 mum when cultured higher than at 39.5 degrees C and at 41.5 degrees C, respectively. Each strain was unable to multiply when cultured higher than at 44.2 degrees C (ATCC 33152) or at 44.0 degrees C (Okinawa 02-001). Those data would provide insights for establishing regulations in terms of maintaining hot water temperature in a facility where a circulating hot water supply-system is available and contamination with Legionella spp. is likely to happen.

Prevención y tratamiento de la neumonía adquirida en la comunidad en pacientes adultos: Un enfoque para la atención primaria

Community-acquired pneumonia is a frequent cause of morbidity, hospitalization and death especially among patients with risk factors. Several agents can provoke this condition and their relevance change according to specific epidemiological exposures, time of the year and comorbidity, being Streptococcus pneumoniae the most frequent etiological agent followed by Mycoplasma pneumoniae, Chlamydia pneumoniae, respiratory viruses and Haemophilus influenzae. Management requires proper identification of the most vulnerable patients and prompt admittance and X-ray confirmation to analyze extension, complications or differential diagnosis. Etiological studies are limited by the low sensitivity and specificity of the sputum Gram stain, the invasive nature of some techniques or the high cost of a comprehensive study. Nonetheless, etiological studies are relevant on severe cases, immunosuppressed patients or those without response to an empirical treatment. New diagnostic tests include serological studies for atypical pathogens, direct detection of viral agents or pneumococcal antigens on sputum samples and Legionella pneumophila serotype 1 antigen detection in urine. Penicillin resistant pneumococcal (PRP) isolates associated to pneumonia or bacteremia as well as isolates with resistance to third generation cefalasporins or macrolides are still infrequently observed among adult patients in Chile. Notwithstanding, worldwide experience indicates that patients affected by PRP isolates and treated with penicillin do not evolve with a higher risk for treatment failure, except for those cases where the MIC for penicillin is equal or higher than 4 µg/mL

An outbreak of Legionella micdadei pneumonia in transplant patients: evaluation, molecular epidemiology, and control

purpose: To describe a nosocomial outbreak of Legionella micdadei pneumonia in transplant patients and to characterize the source of the outbreak and the control measures utilized. subjects and methods: We performed retrospective Legionella micdadei serologic testing to enhance case finding in transplant patients with pneumonia that lacked a documented microbial etiology, as well as prospective environmental surveillance of water sites and testing for Legionella in clinical specimens. results: During a 3-month period, 12 cases of Legionella micdadei pneumonia were identified either by culture or serologic testing among 38 renal and cardiac transplant patients. Legionella micdadei isolates from hot water sources were found by pulsed-field gel electrophoresis to have a DNA banding pattern that was identical to the isolates from the first 3 culture-positive cases and from 2 cases that occurred 16 months later. conclusions: Hospitals caring for organ transplant recipients and other immunosuppressed patients must be aware of the possibility of environmental sources of outbreaks of Legionella infection. A first-line screen with the Legionella urine antigen test will identify Legionella pneumophila serogroup 1. However, specific cultures in outbreak situations should be considered to identify other Legionella pneumophila serotypes and the nonpneumophila Legionella species.