Nocardia infections in Italy: from a local to a national view.

In this paper, we have described cases of nocardiosis that occurred in our hospital and examined the literature on other nocardiosis cases recorded in Italy. We have collected the clinical details of our recent cases and described them in full. Regarding the older cases in our hospital and the Italian cases present in the literature, we noted the clinical data, the Nocardia species involved, and the antimicrobial susceptibility reported. The survey was carried out on PubMed. The first of our cases is an elderly woman with compromised health who had a lung and bloodstream infection. A second case is a middle-aged man who developed an infection in the thigh. A third patient is a middle-aged man on immunosuppressive therapy who developed a cerebral abscess. Our review shows that patients are usually immunocompromised, with an average age of 60 years, and more frequently males. The most affected organs are the lungs and the brain, and the most reported species is Nocardia farcinica. Antimicrobial susceptibility tests show good efficacy of linezolid, cotrimoxazole and amikacin. We conclude that, if a Nocardia infection is suspected, the most likely species to be considered in Italy is N. farcinica. In addition, if empirical therapy is needed, we suggest relying on linezolid, cotrimoxazole or amikacin.

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.

Treatment for Severe Malaria: Post-Artesunate Delayed Haemolysis and Neutropenia.

Parenteral artesunate (AS) is the WHO first-line treatment recommended in adults and children for severe malaria. Post-artesunate delayed haemolysis (PADH) is an uncommon adverse reaction to AS with a mechanism that is not fully understood, occurring in adults and children. Neutropenia is another possible finding after AS treatment, albeit rare. We present the case of a child who experienced both effects after treatment with AS for imported severe Falciparum malaria with very high parasitaemia. In addition, thirty-five paediatric cases of PADH, five cases of delayed anaemia without known haemolysis, and fourteen cases of neutropenia after artesunate treatment were identified from the literature review. PADH seems to be a dose-independent reaction and is not strongly related to hyperparasitaemia, although it is more frequent in this case. To date, the benefits of AS outweigh its potential side effects. However, haematological follow-up is mandatory to avoid possible complications from anaemia and neutropenia, especially in children treated with other contemporary drugs.

Haemophilus parainfluenzae endocarditis in a low-risk woman: a case report.

Haemophilus parainfluenzae endocarditis is a rare but dangerous disease. With this work, we intend to show the importance of early diagnosis and appropriate treatment in order to avoid complications. We also highlight the importance of local epidemiology to choose antibiotic prophylaxis for high-risk procedures in selected predisposed patients.

Suppression of a SARS-CoV-2 outbreak in the Italian municipality of Vo'.

On 21 February 2020, a resident of the municipality of Vo', a small town near Padua (Italy), died of pneumonia due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection1. This was the first coronavirus disease 19 (COVID-19)-related death detected in Italy since the detection of SARS-CoV-2 in the Chinese city of Wuhan, Hubei province2. In response, the regional authorities imposed the lockdown of the whole municipality for 14 days3. Here we collected information on the demography, clinical presentation, hospitalization, contact network and the presence of SARS-CoV-2 infection in nasopharyngeal swabs for 85.9% and 71.5% of the population of Vo' at two consecutive time points. From the first survey, which was conducted around the time the town lockdown started, we found a prevalence of infection of 2.6% (95% confidence interval (CI): 2.1-3.3%). From the second survey, which was conducted at the end of the lockdown, we found a prevalence of 1.2% (95% CI: 0.8-1.8%). Notably, 42.5% (95% CI: 31.5-54.6%) of the confirmed SARS-CoV-2 infections detected across the two surveys were asymptomatic (that is, did not have symptoms at the time of swab testing and did not develop symptoms afterwards). The mean serial interval was 7.2 days (95% CI: 5.9-9.6). We found no statistically significant difference in the viral load of symptomatic versus asymptomatic infections (P = 0.62 and 0.74 for E and RdRp genes, respectively, exact Wilcoxon-Mann-Whitney test). This study sheds light on the frequency of asymptomatic SARS-CoV-2 infection, their infectivity (as measured by the viral load) and provides insights into its transmission dynamics and the efficacy of the implemented control measures.

Intra-hospital acquisition of colonization and infection by Klebsiella pneumoniae strains producing carbapenemases and carriage evolution: A longitudinal analysis in an Italian teaching hospital from January 2017 to August 2019.

OBJECTIVES: We present an updated picture (1/1/2017-31/08/2019) of the frequency of carbapenemase producing Klebsiella pneumoniae (CPKP) in surveillance rectal swabs (SRS) and in clinical samples (CS) of patients admitted to a tertiary level hospital, focusing on longitudinal evolution of CPKP detected in SRS and on colistin resistant strains. METHODS: Retrospective longitudinal analysis. Only the first positive CPKP strain isolated from each patient was included. RESULTS: 638 CPKP strains were identified (471 in SRS and 167 in CS). SRS frequency increased over time in the medical department, remained high in the surgical department (SD) and decreased in the intensive care department. Most SRS-71.3%-and 49.1% of CS had nosocomial origin; about half of the SRS were identified in the SD. Regarding SRS evolution, carriage was confirmed in 39.5% of patients, no more testing in 25.5%, clinical involvement in 24.8 %, and negative result in 10.2%. Rates of colistin resistance were 20.1% in 2017, 31.2% in 2018 and 26.9% in 2019. CONCLUSIONS: CPKP diffusion is still an important issue despite the surveillance program. It is vital to enhance medical staff's awareness on this because most CPKP first detections in SRS occurred during hospital stay due to a nosocomial acquisition with a comparable picture over time. Colistin resistance is increasing.

A first molecular characterization of Listeria monocytogenes isolates circulating in humans from 2009 to 2014 in the Italian Veneto region.

Listeriosis is a disease usually associated with the consumption of low-processed ready-to-eat food products contaminated by Listeria monocytogenes. In Italy, listeriosis has an incidence of 0.19-0.27 cases per 100000 persons. Since detailed information concerning the molecular characterization of listeriosis in the Italian Veneto region is currently lacking, we analyzed 36 L. monocytogenes clinical isolates collected between 2009 and 2014. Results show that the serotype 1/2a was the most represented among the tested samples. No antimicrobial resistance was detected in selected isolates representing the main pulsotypes.

Plasmodium knowlesi malaria in a traveller returning from the Philippines to Italy, 2016.

Plasmodium knowlesi is a simian parasite responsible for most human cases of malaria in Malaysian Borneo. A timely recognition of infection is crucial because of the risk of severe disease due to the rapid increase in parasitemia. We report a case of P. knowlesi infection in a traveller who developed fever and thrombocytopenia after returning from the Philippines in 2016. Rapid antigen test was negative, microscopy examination showed parasites similar to Plasmodium malariae, with a parasite count of 10,000 parasites per µL blood, while molecular testing identified P. knowlesi infection. Treatment with atovaquone-proguanil led to resolution of fever and restoration of platelet count in two days. P. knowlesi infection should be suspected in febrile travellers returning from South East Asia. Due to the low sensitivity of rapid antigen tests and the low specificity of microscopy, confirmation by molecular tests is recommended.

Prevalence, molecular epidemiology and intra-hospital acquisition of Klebsiella pneumoniae strains producing carbapenemases in an Italian teaching hospital from January 2015 to September 2016.

OBJECTIVES: We described Klebsiella pneumoniae producing carbapenemase (CPKP) spread from 01/01/2015 to 13/09/16 in a tertiary level hospital. METHODS: The first positive surveillance rectal swab (SRS) or clinical sample (CS) collected in the medical department (MD), surgical department (SD) and intensive care department (ICD) were included in the study. A validated in-house Real-Time PCR method was used to detect carbapenemases; multilocus sequence typing (MLST) was used for further characterization of the strains. RESULTS: 21535 patients were included: 213 CPKP strains from surveillance rectal swab (SRS) and 98 from clinical samples (CS) were collected. The percentage of CPKP detected in SRS with respect to CS increased in the medical MD from 2015 to 2016 (p=0.01) and in ICD from 2012 to 2015 (p=0.0001), while it decreased in SD from 2014 to 2016 (p=0.003); 68.5% of the positive SRS had a previous negative SRS; CPKP was more frequently identified in CS than in SRS in MD. Twelve strains harboured more than one carbapenemase gene. Many other species harbouring a carbapenemase gene were collected. CONCLUSIONS: MDs need more inclusive surveillance criteria. The late detection of positive SRS underlined the risk of colonization during hospitalization.

Serotype epidemiology and multidrug resistance patterns of Salmonella enterica infecting humans in Italy.

BACKGROUND: Salmonella enterica is the zoonotic agent most frequently responsible for foodborne infections in humans worldwide. In this work the presence of S. enterica was investigated in 734 unique enteropathogenic isolates collected from human patients between 2011 and 2012. RESULTS: All Salmonella spp. isolates were subjected to serotyping and antimicrobial susceptibility testing. Isolates displaying phenotypes and antimicrobial susceptibility profiles different from the reference strains were genotipically characterized. Several plasmid-embedded resistance determinants were identified and characterized. Non-typhoidal serotypes were most frequently diagnosed; monophasic Salmonella typhimurium 1,4 [5],12:i- and S. typhimurium represented the most prevalent serovars. Five isolates displayed phenotypes with extremely reduced susceptibility to antimicrobials: we detected multidrug resistance elements belonging to Ambler class A and class C in two non-typhoidal S. enterica serovars, i.e. Rissen and monophasic S. typhimurium 1,4 [5],12:i-, and in one typhoidal serovar, i.e., Paratyphi B. These resistance determinants have been so far almost exclusively associated with non-Salmonella members of the Enterobacteriaceae family. Alarmingly, two colistin resistant Salmonella enteritidis were also found. CONCLUSIONS: This work draws the attention to the still low, but rising, percentage of multidrug resistant Salmonella isolates infecting humans in Italy. Our results suggest that prompt monitoring of Salmonella serovar dissemination and resistance to antimicrobials is highly required.

Prevalence of Klebsiella pneumoniae strains producing carbapenemases and increase of resistance to colistin in an Italian teaching hospital from January 2012 To December 2014.

BACKGROUND: The aim of this study was to characterize the spread of carbapenemase-producing Klebsiella pneumoniae (CPKP) in a tertiary level hospital using ongoing active surveillance with rectal swab cultures. Furthermore, this study analyzed the presence of CPKP in the clinical samples (CS) of a single patient as well as the evolution of Colistin-sensitive strains (CoS) to Colistin-resistant strains (CoR). METHODS: This study was performed from January 1, 2012 to December 31, 2014. In 2012, a survey was conducted in the Intensive Care Department. In autumn 2013, active monitoring was extended to the Surgery Department, and since mid-2014, the surveillance has included the Medical Department as well. Only the first isolated strain from each patient was included. Antimicrobial susceptibility testing was performed on CPKP isolates: Klebsiella pneumoniae carbapenemase, oxacillinase-48, Verona integron-encoded metallo-ß-lactamase and New Delhi metallo-ß-lactamase were detected using a validated in-house PCR method, and multilocus sequence typing (MLST) was used to investigate the clonal transmission of strains. RESULTS: A total of 15,104 patients were included in the study, and 496 consecutive non-replicated strains of CPKP were collected: 149 strains were collected in 2012 (39 [26.2 %] from surveillance rectal swabs [SRS]), 133 strains were collected in 2013 (70 [52.6 %] from SRS) and 214 strains were collected in 2014 (164 [76.6 %] from SRS). We observed a significant increase in the percentage of positive SRS cases in 2014 relative to 2013 and 2012 (p = 0.0001 and p = 0.0172, respectively) and in the proportion of CPKP first isolated by SRS relative to those identified by CS (p < 0.0001). Among all available samples, the number of CoR isolated from SRS was higher in 2013 and 2014 compared with 2012 (p = 0.0019 and p = 0.008, respectively). ST-258 and ST-512 were more prevalent in the tested specimens, and a new single locus variant (SLV) of ST-512 (ST-745) was isolated. CONCLUSIONS: The results of this 3-year study of 15,104 patients highlight the clinical relevance of antimicrobial resistance as well as the drug-selection pressure of colistin therapy. The active surveillance in the three different departments increased the level of CPKP cases isolated by SRS.

Multilocus sequence typing of Campylobacter jejuni and Campylobacter coli from humans and chickens in North-Eastern Italy.

This paper reports the multilocus sequence typing (MLST) of 57 C. jejuni and C. coli isolates from humans and chickens in Italy and the identification of 17 new sequence types (STs). A high genetic diversity was detected among C. jejuni/C. coli and human/chicken isolates, with a predominance of clonal complexes CC21 and CC828. Although human STs were not the same as those found in chickens, 3 CCs overlapped between human and chicken isolates. Genotyping of Campylobacter strains by MLST should be encouraged in order to implement surveillance and con- trol of infection in humans and in animal reservoirs in Italy.