Mycobacterium chimaera Infections in a Unit of Cardio Surgery: Study at a General Hospital in Padua, Italy.

Mycobacterium chimaera is a slow-growing non-tuberculous mycobacterium already known for being able to colonize cardio surgery heater-cooler units (HCUs). This study aims to describe the real magnitude of the phenomenon, providing a methodological protocol and the results of a longitudinal survey. In the period 1 January 2017-23 May 2022, over 1191 samples were collected on 35 HCUs of two different manufacturers. Among them, we identified 118 (10.3%) positive results for M. chimaera. We propose our 4-year biosurveillance experience as a practical model to minimize microbiological patients' risk, suggesting the need for new procedures and interventions for a safer and more ecological cardio surgery.

Successful Control of an Outbreak by Phenotypically Identified Extended-Spectrum Beta-Lactamase-Producing Klebsiella pneumoniae in a Neonatal Intensive Care Unit.

BACKGROUND: Premature newborns represent a vulnerable population, at high risk of acquiring nosocomial infections during neonatal intensive care unit (NICU) admission. Multidrug-resistant organisms represent the greatest concern due to their intrinsic virulence and the limited therapeutic options. Resistant Enterobacterales are a growing threat for critically ill neonates, with increasing numbers of NICU outbreaks caused by extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales being described. This study reports the early detection and successful control of an outbreak caused by ESBL-producing Klebsiella pneumoniae (ESBL-KP) in an Italian NICU in February 2021. RESULTS: A total of 13 newborns tested positive for ESBL-KP between 2-9 February 2021, of whom four (31%) had a bloodstream infection. Two were critically ill, extremely premature newborns who died because of multiple comorbidities, and two were cured after treatment with meropenem. All other patients survived and were either discharged home or moved to other hospitals/wards in good clinical condition. ESBL-KP ST45 was found in all isolates by multilocus sequence typing (MLST) analysis. An outbreak control plan was set, including surveillance cultures for all neonates, NICU environments, and medical devices, along with the extended use of contact precautions and cohorting. In addition, the infection control plan was carried out through reinforcement and enhancement measures to guarantee maximal compliance. The outbreak was successfully controlled in seven days, given that no further cases were identified after 9 February. The source of the ESBL-KP outbreak was not identified through environmental sampling. CONCLUSIONS: Thanks to multidisciplinary management, a threatening outbreak of ESBL-KP in a NICU was controlled in few days. The prompt recognition of the event onset and the adoption of infection control interventions helped contain the bacteria spread on the ward.

Epidemiological and clinical features of imported malaria at the three main hospitals of the Friuli-Venezia Giulia Region, Italy.

BACKGROUND: Imported malaria cases continue to occur in non-endemic regions among travellers returning from tropical and subtropical countries. At particular risk of acquiring malaria is the group of travellers identified as immigrants who return to their home country with the specific intent of visiting friends or relatives (VFRs) and who commonly believe they are immune to malaria and fail to seek pre-travel advice. Our aim was to review the current trends of imported malaria in the three main hospitals of the Friuli-Venezia Giulia region (FVG), North Eastern Italy, focusing in particular on patient characteristics and laboratory findings. METHODS: In this retrospective study, we examined all malaria cases among patients admitted from January 2010 through December 2014 to the emergency department of the three main hospitals located in FVG. RESULTS: During the 5-year study period from 2010 to 2014, there were a total of 140 patients with a diagnosis of suspected malaria and who received microscopic confirmation of malaria. The most common species identified was P. falciparum, in 96 of 140 cases (69%), followed by P. vivax (13%), P. ovale (4%), P. malariae (4%), and mixed infection (4%). The most common reason for travel was VFRs (54%), followed by work (17%), and recent immigration (15%). Moreover, 78% of all patients took no chemoprophylaxis, 80 (79%) of whom were foreigners. Notably, the percentage of Italian travellers who took chemoprophylaxis was only 20% (8 of 39 Italian cases), and the regimen was appropriate in only four cases. Parasitaemia greater than 5% was observed in 11 cases (10%), all due to P. falciparum infection. CONCLUSIONS: We highlight that VFRs have the highest proportion of malaria morbidity and the importance of improving patient management in this category. These data are useful for establishing appropriate malaria prevention measures and recommendations for international travellers.

Recurrent skin infection associated with nasal carriage of Panton-Valentine leukocidin-positive methicillin-susceptible Staphylococcus aureus closely related to the EMRSA-15 clone.

We report the case of a soldier with recurrent skin infection associated with nasal carriage of a Panton-Valentine leukocidin (PVL)-producing methicillin-susceptible Staphylococcus aureus (MSSA), closely related to the EMRSA-15 clone. MSSA isolates causing infection not requiring hospitalization usually go unnoticed; however, their typing may be useful to understand the global distribution of successful staphylococcal lineages related to epidemic clones. PVL-positive MSSA strains might serve as reservoirs from which virulent methicillin-resistant strains may evolve and spread.

Direct molecular detection of pathogens in blood as specific rule-in diagnostic biomarker in patients with presumed sepsis: our experience on a heterogeneous cohort of patients with signs of infective systemic inflammatory response syndrome.

The practical value of blood cultures in the diagnosis of sepsis is impaired by a delay in the turnaround time to result and by the fact that blood culture positive can be found for only about 30% of these patients. Conventional laboratory signs of sepsis and acute phase protein biomarkers are sensitive and easy to use, but often also very nonspecific. Molecular diagnostic reflects currently the most promising avenue to decrease time to result and to influence decision making for antibiotic therapy in the septic host. In this study, we wish to highlight the impact of the LightCycler SeptiFast, a multipathogen probe-based real-time polymerase chain reaction, in the rapid etiological diagnosis of sepsis in patients with clinical and laboratory signs of bloodstream infections. We have evaluated prospectively 830 adult patients with suspected bloodstream infection and at least two criteria of systemic inflammatory response syndrome. In more than 50% of critically ill patients strongly suspected of having sepsis, we arrived to an etiological diagnosis only by the molecular method in a median time of 15 h, with specificity and predictive positive values of 96% and 94%, respectively. We highlight the role of DNAemia as time-critical, high-specificity, etiological, non-culture-based rule-in diagnostic biomarker in patients with presumed sepsis.

When should adenoviral non-gonococcal urethritis be suspected? Two case reports.

The impact of Adenovirus as agent of non-gonococcal urethritis (NGU) is still poorly documented in the literature. We describe two cases showing that adenoviral infection should be reasonably hypothesized in men with dysuria and scant urethral discharge in addition to meatus inflammation and/or edema (meatitis) or conjunctivitis. Case 1: a 55-year-old man came to our observation in July 2012 referring a 5-day-history of intense dysuria and scant mucoid urethral discharge. Physical examination revealed the urethral discharge referred, but also modest meatitis and an intense conjunctival hyperemia on his right eye. Adenoviral infection was investigated and Adenovirus DNA (type 37) was detected in both the urethral and conjunctival swabs. Case 2: a 43-year-old man with intense dysuria, started 4-5 days earlier, came to our attention with his wife in August 2012. Scant urethral mucoid secretions, severe meatal inflammation of the male patient were revealed during physical examination. His wife instead complained of a 2-day history of intense burning eyes. Adenoviral infection was investigated and Adenovirus DNA (type 37) was positive both in the male urethral swab and in his wife's conjunctival swab. Adenovirus seems to cause a distinct and recognisable clinical syndrome in men presenting with urethritis. Studies on the prevalence and role of Adenovirus as a causative agent of urethritis are limited. Moreover, as rapid advanced molecular microbiology is now available, we believe that extending the search to Adenovirus in sexually active men with dysuria, scant discharge in addition to meatitis or conjunctivitis, should be a useful approach improving our understanding about adenoviral NGU, and especially avoiding or stopping unnecessary empirical antibiotic therapy.

Methicillin-resistant Staphylococcus aureus infection rate after implementation of an antibiotic care bundle based on results of rapid molecular screening.

AIM: Colonization with methicillin-resistant Staphylococcus aureus (MRSA) is a risk factor for subsequent invasive MRSA infection, particularly in patients admitted to critical areas. We conducted a surveillance among patients admitted to our Intensive Care Unit (ICU) to determine whether the implementation of a specific MRSA antibiotic care bundle (ACB) based on rapid molecular screening for MRSA and de-colonization, reduced the total MRSA infection rate. MATERIALS AND METHODS: A total of 431 and 577 nasal swabs were obtained from ICU patients at admission from April 2009 through December 2010 (pre-ACB period) and, after the bundle implementation, from January 2011 through December 2012 (post-ACB period), respectively. Nasal swabs were analyzed by the rapid molecular test Xpert MRSA. All patients were followed-up during their whole ICU stay to determine whether they developed MRSA infection. RESULTS: Overall, 31 out of 431 (7.1%) patients were colonized with MRSA at admission during the pre-ACB period and 49 out of 577 (8.4%) were colonized with MRSA during the post-ACB period. The rate of MRSA infection in ICU significantly declined from 2% in pre-ACB to 0.3% in post-ACB, with a total decrease of 100% in two consecutive semesters between July 2011 and July 2012 (p<0.001). CONCLUSION: The analysis demonstrated a significant decline in MRSA infections following the introduction of active rapid molecular surveillance and the specific ACB at our ICU and in the risk associated with MRSA bacteremia.

An antibiotic care bundle approach based on results of rapid molecular screening for nasal carriage of methicillin-resistant Staphylococcus aureus in the intensive care unit.

The potential role of active methicillin-resistant Staphylococcus aureus (MRSA) surveillance in the intensive care unit (ICU), has been recently proposed as a guide for antibiotic treatment in patients suspected of being infected with MRSA by using an antibiotic care bundle (ACB) approach. A group of 376 consecutive ICU patients were prospectively screened for nasal carriage of MRSA using a real-time polymerase chain reaction test. The study group consisted of 244 (64.9%) males and (35.1%) females, with a median age of 64 (range 17-95 years). Overall, 26 (6.9%) patients were positive for MRSA, while 350 (93.1%) were MRSA-negative. No difference was observed in gender and age between groups. During ICU stay, 9 (2.4%) patients developed generalized MRSA infection, of whom 8 out of 26 (30.8%) were MRSA-carriers and one out of the 350 (0.3%) was MRSA-negative. Thus, a strong relationship between MRSA infection and MRSA carriage (relative risk=107.7, 95% confidence interval=14.0-828.5, p<0.0001) was found. Subsequently, in our ICU, we developed and introduced a new ACB approach based on rapid nasal screening results for improving the management of critically ill patients. The use of anti-MRSA agents should be re-evaluated daily on the basis of clinical and laboratory features, with positive cultures from sterile site or signs of active infection supporting prolongation of empirical treatment. On the contrary, MRSA-negative clinical cultures support a de-escalation strategy. In conclusion, the early identification of MRSA-carriers using a rapid molecular screening is safe and accurate, allowing MRSA-positive patients, who will more likely develop MRSA infections, to be detected.

Evaluation of the Sysmex UF1000i flow cytometer for ruling out bacterial urinary tract infection.

BACKGROUND: Urine culture is one of the most frequently requested tests in microbiology, and it represents the gold standard for the diagnosis of UTIs. Considering the high prevalence of negative results and the long TAT of the culture test, the use of a rapid and reliable screening method is becoming more and more important, as it reduces the workload, the TAT of negative results, and above all, unnecessary antibiotic prescription. METHODS: The Sysmex UF1000i is a new urine flow cytometry analyzer capable of quantifying urinary particles, including BACT, WBCs, and YLCs. To evaluate the analytical performance of the UF1000i as a method for ruling out UTIs, we examined 1349 urine samples and compared the UF1000i results with standard urine culture results. RESULTS: With instrument cut-off values of 170BACTx10(6)/L and 150WBCsx10(6)/L, we obtained a sensitivity of 98.8%, a specificity of 76.5%, a NPV of 99.5%, and four false negative results (1.2%), avoiding the culture of 57.1% of samples. CONCLUSION: The Sysmex UF1000i was capable of improving the efficiency of a routine microbiology laboratory by processing 100samples/h and providing negative results in a few minutes, thus reducing unnecessary testing with an acceptable number of false negative results. In addition, the preliminary evaluation of B_FSC and B_FLH parameters from bacteria histograms seems to be useful for the distinction of bacterial strains detected (Gram-negatives versus Gram-positives). In fact when B_FSC was less than 30 ch, it allowed the distinction of Gram-negative bacteria in 97% of the samples.

Molecular identification of bloodstream pathogens in patients presenting to the emergency department with suspected sepsis.

The rapid detection of pathogens in blood is critical for a favorable outcome of patients with suspected sepsis. Although blood culture (BC) is considered the criterion standard for diagnosis of bloodstream infection, it often takes several days to detect the causative organism. In this study, we compared BC with a commercially available multiplex real-time polymerase chain reaction (PCR) assay to detect bacteria and fungi in blood samples from 144 patients admitted to the emergency department with suspected sepsis. Of 144 blood samples examined, 91 (63%) were negative by both methods and 53 (37%) were positive by at least one of the two methods. In 30 among all positive cases (56.6%),both methods identified the same organisms, in 13 cases (24.5%), BC identified organisms not detected by real-time PCR,and in 10 cases (18.9%), SeptiFast PCR assay gave positive results, whereas the BC was negative. In this study, we wished to compare SeptiFast results obtained by standard procedures, but future clinical studies are necessary to define SeptiFast PCR as support for BC in the early diagnosis of severe bloodstream infections.

[Disappearance of Streptococcus pyogenes macrolide resistance in an area of northeastern Italy: a possible link with rational long-acting macrolide consumption]. / Scomparsa della resistenza di Streptococcus pyogenes ai macrolidi in un'area del nord est e possibile nesso con il razionale utilizzo di molecole long-acting.

Many studies have shown a correlation between higher consumption of long-acting macrolides and the development of resistance of S. pyogenes but, to our knowledge, no studies have reported the disappearance of S. pyogenes macrolide resistance. We evaluated the possible relationship between the rational use of long-acting macrolide consumption and the disappearance of S. pyogenes erythromycin resistance in an area of northeastern Italy, the district of Pordenone (approximately 300,000 inhabitants). The emerging use of new long-acting macrolides, especially since 1993, has caused a great increase in total macrolide consumption (expressed as defined daily doses per 1,000 inhabitants per day; DDDs), followed by a steady increase in the percentage of S. pyogenes resistant to erythromycin (from 4% in 1994 to 56.3% in 2000). Subsequently, from 2000 to 2007, the maintenance of steady-high DDDs of clarithromycin but low DDDs of azithromycin resulted in a sharp decrease in the percentage of S. pyogenes resistance to erythromycin (from 33.3% in 2001 to 0.2% in 2008). Disappearance of S. pyogenes erythromycin resistance in the last few years, compared with data of long-acting macrolide consumption from 2000 to 2007, suggests that S. pyogenes resistance to erythromycin is more likely associated with the specific type of compound used rather than with total consumption of long-acting macrolides.

App1: an antiphagocytic protein that binds to complement receptors 3 and 2.

In previous studies, we showed that the pathogenic fungus Cryptococcus neoformans (Cn) produces a specific and unique protein called antiphagocytic protein 1 (App1), which inhibits phagocytosis of Cn by alveolar macrophages (AMs). Phagocytosis of Cn by AMs occurs mainly through a complement- or Ab-mediated mechanism. Among AM receptors, complement receptor 3 (CR3) and FcRgamma are the most common receptors involved in the phagocytic process. Because App1 inhibits phagocytosis of complement- but not Ab-coated erythrocytes, we investigated the role of CR3 in App1-macrophage interactions. We found that App1 binds to CR3 and if CR3 is absent from the surface of AMs, its antiphagocytic action is lost. When we investigated whether App1 would also bind to other complement receptor(s), we found that App1 does bind to complement receptor 2 (CR2) in a dose-dependent manner. In certain lymphoma cell lines, cellular proliferation is stimulated by complement through CR2, providing a potential use of App1 as a proliferation inhibitor of these cells. Initially discovered as an antiphagocytic protein regulating CR3-mediated innate immunity, App1 may also play a key role in the regulation of acquired immunity, because CR2 is mainly localized on B cells.

NPM/ALK binds and phosphorylates the RNA/DNA-binding protein PSF in anaplastic large-cell lymphoma.

The oncogenic fusion tyrosine kinase nucleophosmin/anaplastic lymphoma kinase (NPM/ALK) induces cellular transformation in anaplastic large-cell lymphomas (ALCLs) carrying the t(2;5) chromosomal translocation. Protein-protein interactions involving NPM/ALK are important for the activation of downstream signaling pathways. This study was aimed at identifying novel NPM/ALK-binding proteins that might contribute to its oncogenic transformation. Using a proteomic approach, several RNA/DNA-binding proteins were found to coimmunoprecipitate with NPM/ALK, including the multifunctional polypyrimidine tract binding proteinassociated splicing factor (PSF). The interaction between NPM/ALK and PSF was dependent on an active ALK kinase domain and PSF was found to be tyrosine-phosphorylated in NPM/ALK-expressing cell lines and in primary ALK(+) ALCL samples. Furthermore, PSF was shown to be a direct substrate of purified ALK kinase domain in vitro, and PSF Tyr293 was identified as the site of phosphorylation. Y293F PSF was not phosphorylated by NPM/ALK and was not delocalized in NPM/ALK(+) cells. The expression of ALK fusion proteins induced delocalization of PSF from the nucleus to the cytoplasm and forced overexpression of PSF-inhibited proliferation and induced apoptosis in cells expressing NPM/ALK. PSF phosphorylation also increased its binding to RNA and decreased the PSF-mediated suppression of GAGE6 expression. These results identify PSF as a novel NPM/ALK-binding protein and substrate, and suggest that PSF function may be perturbed in NPM/ALK-transformed cells.

Constitutive activation of Jak2 contributes to proliferation and resistance to apoptosis in NPM/ALK-transformed cells.

OBJECTIVE: The t(2;5) translocation results in a 80-kDa oncogenic fusion protein consisting of NPM and the kinase domain of the tyrosine kinase ALK and is present in over half the cases of anaplastic large cell lymphoma (ALCL). NPM/ALK exerts its transforming potential via activation of multiple signaling pathways promoting growth factor independence and protection from apoptosis. Jak/Stat signaling is aberrantly activated in several human hematopoietic malignancies. We investigated the role of Jak2 in the context of NPM/ALK-mediated oncogenesis. MATERIALS AND METHODS: Constitutive tyrosine phosphorylation of Jak2 was analyzed by Jak2 immunoprecipitation and subsequent anti-phosphotyrosine Western blotting. NPM/ALK-transformed cells were treated with the Jak2 inhibitor AG490 or transfected with wild-type or dominant-negative Jak2 expression constructs to measure 3[H]-thymidine incorporation. Apoptosis was assessed by flow cytometric analysis of annexin V-stained cells. The effect of Jak2 on Stat5-dependent transcriptional activity was measured by beta-casein promoter-dependent luciferase expression. RESULTS: Jak2 was found to be constitutively tyrosine phosphorylated in ALCL cells and in NPM/ALK-transformed hematopoietic cells. Also, NPM/ALK was present in immunoprecipitates of Jak2. Inhibition of Jak2 led to a reduction of NPM/ALK-mediated proliferation and induced apoptosis. Stat5-dependent transcriptional activity was inhibited by transfection of NPM/ALK-transformed cells with a dominant-negative Jak2 expression construct or treatment with AG490. CONCLUSION: Constitutive activation of Jak2 constitutes a pro-proliferative, anti-apoptotic signaling pathway in NPM/ALK-transformed hematopoietic cells.