Pseudomonas aeruginosa in a neonatal intensive care unit: molecular epidemiology and infection control measures

<p>Abstract</p> <p>Background</p> <p><it>Pseudomonas aeruginosa</it>, a non-fermentative, gram-negative rod, is responsible for a wide variety of clinical syndromes in NICU patients, including sepsis, pneumonia, meningitis, diarrhea, conjunctivitis and skin infections. An increased number of infections and colonisations by <it>P. aeruginosa </it>has been observed in the neonatal intensive care unit (NICU) of our university hospital between 2005 and 2007.</p> <p>Methods</p> <p>Hand disinfection compliance before and after an educational programme on hand hygiene was evaluated. Identification of microrganisms was performed using conventional methods. Antibiotic susceptibility was evaluated by MIC microdilution. Genotyping was performed by PFGE analysis.</p> <p>Results</p> <p>The molecular epidemiology of <it>Pseudomonas aeruginosa </it>in the NICU of the Federico II University hospital (Naples, Italy) and the infection control measures adopted to stop the spreading of <it>P. aeruginosa </it>in the ward were described. From July 2005 to June 2007, <it>P. aeruginosa </it>was isolated from 135 neonates and caused severe infections in 11 of them. Macrorestriction analysis of clinical isolates from 90 neonates identified 20 distinct genotypes, one major PFGE type (A) being isolated from 48 patients and responsible for 4 infections in 4 of them, four other distinct recurrent genotypes being isolated in 6 to 4 patients. Seven environmental strains were isolated from the hand of a nurse and from three sinks on two occasions, two of these showing PFGE profiles A and G identical to two clinical isolates responsible for infection. The successful control of the outbreak was achieved through implementation of active surveillance of healthcare-associated infections in the ward together with environmental microbiological sampling and an intense educational programme on hand disinfection among the staff members.</p> <p>Conclusion</p> <p><it>P. aeruginosa </it>infections in the NICU were caused by the cross-transmission of an epidemic clone in 4 neonates, and by the selection of sporadic clones in 7 others. An infection control programme that included active surveillance and strict adherence to hand disinfection policies was effective in controlling NICU-acquired infections and colonisations caused by <it>P. aeruginosa</it>.</p

Environmental surveillance and in vitro activity of antimicrobial agents against Legionella pneumophila isolated from hospital water systems in Campania, South Italy: a 5-year study.

Abstract Background Legionellosis' treatment failures have been recently reported showing the possibility of resistance development to traditional therapy, especially in healthcare related disease cases. Environmental impact of antibiotic residues, especially in hospital waters, may act on the resistome of Legionella resulting in developing resistance mechanisms. Objectives In this study we investigate the antibiotic susceptibility of environmental Legionella pneumophila (Lpn) strains isolated from hospital water systems in Campania, a region located in Southwest Italy. Methods 5321 hospital water samples were investigated for the presence of Lpn. Among positive samples, antibiotic susceptibility was tested for a random subset of 125 Lpn strains (25 Lpn isolates from each of the following serogroups: 1, 3, 5, 6, 8). Susceptibility testing was performed, using the E-test on buffered charcoal yeast extract agar supplemented with α-ketoglutarate, for 10 antimicrobial drugs: azithromycin, cefotaxime, clarithromycin, doxycycline, erythromycin, rifampicin, tigecycline, ciprofloxacin, levofloxacin and moxifloxacin. Non parametric tests were used to determine and assess the significant differences in susceptibility to the different antimicrobics between the serogroups. Results Among the isolated strains, none showed resistance to the antibiotics tested. Rifampicin was the most active antibiotic against overall Legionella strains, followed by levofloxacin. Between the macrolides the clarithromycin was overall the most active drug, instead the azithromycin was the less active. Analyzing the different serogroups a significant difference was found between serogroup 1 and non-1 serogroup isolates for doxycycline and tigecycline. Conclusions Antibiotic susceptibility of environmental isolates of Legionella spp. might be useful for the early detection of resistance to antibiotics that directly impacts on mortality and length of hospital stay

Monitoraggio ambientale di Legionella in presidi ospedalieri della Regione Campania: risultati preliminari

Introduzione e obiettivo: Legionella è un patogeno Gram-negativo che colonizza l'acqua. Tra gli individui più colpiti ci sono quelli con immunodeficienze: di conseguenza, è necessario monitorare la presenza del batterio negli ospedali, in quanto luogo in cui risiedono soggetti immunocompromessi. Lo scopo di questo studio è stato quello di valutare la presenza di Legionella in campioni d'acqua della Regione Campania, identificare le specie e i sierogruppi e valutare l'influenza della temperatura dell'acqua e del cloro residuo sulla sua presenza. Metodi: 3365 campioni d’acqua sono stati raccolti da gennaio 2018 a dicembre 2022 in 26 presidi ospedalieri da rubinetti, docce, boiler e unità di trattamento dell'aria (UTA). Ogni campione è stato prelevato circa due volte l'anno. Il campionamento e l'analisi microbiologica sono stati condotti in conformità alla norma UNI EN ISO 11731:2017. L’analisi statistica è stata effettuata mediante test non parametrico di Mann-Whitney, al fine di valutare la relazione tra presenza di Legionella, temperatura dell’acqua e cloro residuo, e poi mediante un’analisi di regressione lineare multipla. Risultati: 708 campioni (21,0%) sono risultati positivi per Legionella. La percentuale di positività è diminuita dal 34,2% nel 2018 al 14,7% nel 2022. Tra i campioni positivi, il 98,6% è risultato positivo per L. pneumophila (70,9% per il sierogruppo 2-14 e 27,7% per il sierogruppo 1) e l’1,4% per Legionella spp. Per il sierogruppo 2-14 sul totale dei positivi, sono stati identificati il 6 (24,5%), l’8 (23,3%), il 3 (18,9%), il 5 (3,1%) e il 10 (1,1%). La media batterica osservata è stata di 2,92 Log10 UFC/L. L’analisi statistica ha mostrato una correlazione negativa, statisticamente significativa, tra la presenza di Legionella ed il cloro residuo, ma non con la temperatura dell’acqua. Conclusioni: I risultati hanno evidenziato la presenza di Legionella in diversi presidi ospedalieri della Campania, rilevando positività in percentuali elevate anche per sierogruppi diversi dall'1 (come il 6, l’8 ed il 3). Questi dati suggeriscono la necessità di continuare il monitoraggio ambientale di Legionella e di concentrarsi sulla diagnosi clinica anche di sierogruppi diversi dall’1, considerato che il test più utilizzato per la diagnosi di Legionella in campioni umani (quello per la ricerca dell’antigene urinario) ha una sensibilità bassa per L. pneumophila di tipo non 1, con conseguente sottonotifica delle infezioni da Legionella. Inoltre, la relazione tra Legionella e cloro residuo conferma che la disinfezione con il cloro è un metodo efficace per il controllo della contaminazione da Legionella

Environmental Monitoring of <i>Legionella</i> in Hospitals in the Campania Region: A 5-Year Study

Legionella is a pathogen that colonizes soils, freshwater, and building water systems. People who are most affected are those with immunodeficiencies, so it is necessary to monitor its presence in hospitals. The purpose of this study was to evaluate the presence of Legionella in water samples collected from hospitals in the Campania region, Southern Italy. A total of 3365 water samples were collected from January 2018 to December 2022 twice a year in hospital wards from taps and showers, tank bottoms, and air-treatment units. Microbiological analysis was conducted in accordance with the UNI EN ISO 11731:2017, and the correlations between the presence of Legionella and water temperature and residual chlorine were investigated. In total, 708 samples (21.0%) tested positive. The most represented species was L. pneumophila 2–14 (70.9%). The serogroups isolated were 1 (27.7%), 6 (24.5%), 8 (23.3%), 3 (18.9%), 5 (3.1%), and 10 (1.1%). Non-pneumophila Legionella spp. represented 1.4% of the total. Regarding temperature, the majority of Legionella positive samples were found in the temperature range of 26.0–40.9 °C. An influence of residual chlorine on the presence of the bacterium was observed, confirming that chlorine disinfection is effective for controlling contamination. The positivity for serogroups other than serogroup 1 suggested the need to continue environmental monitoring of Legionella and to focus on the clinical diagnosis of other serogroups

Intestinal microbiota in adult patients with Short Bowel Syndrome: Preliminary results from a pilot study

Introduction: Intestinal bacterial flora plays a central role in human intestinal health and disease. Short Bowel Syndrome (SBS), a clinical condition deriving from extensive bowel resections, influence intestinal microbiota (IM) composition in order to reach a new metabolic balance. Little is known about IM in adult patients after wide intestinal resections. Material and methods: Fecal samples from 12 SBS patients and 16 controls were analyzed in their microbial profile by using both culture-dependent method and quantitative Real-Time PCR (qRT-PCR). Results: The two methods revealed significant lower concentrations of . Bacteroidetes (p-value = .02), . Firmicutes (p-value = .05), . Bifidobacterium (p-value &lt; .01), and . Methanobrevibacter Smithii (p-value = .04) in SBS patients than controls. Conclusions: The significantly different fecal microbiome in SBS patients compared with healthy controls could open new perspectives on the care of their intestinal functions