Paolo Fazii

Methicillin-Resistant Staphylococcus pseudintermedius Infection in a Bone Marrow Transplant Recipient

ABSTRACT Staphylococcus pseudintermedius is a veterinary pathogen that has seldom been described as an agent of human disease. Features of this probably underreported coagulase-positive Staphylococcus species are depicted here through the description of a graft-versus-host disease-related wound infection caused by a multidrug-resistant strain.

Tuberculosis-like pneumonias by the aerobic actinomycetes Rhodococcus, Tsukamurella and Gordonia

The order Actinomycetales includes phylogenetically diverse but morphologically similar aerobic and anaerobic organisms, exhibiting filamentous branching structures which fragment into rods or coccoid forms. Lung pathogens of the order comprise Mycobacterium, Nocardia, Corynebacterium, Actinomyces, Kytococcus, Rothia, Williamsia, as well as Gordonia, Tsukamurella and Rhodococcus. Particularly, members of the last three genera are uncommon aerobic agents of lung cavitations and tuberculosis(TB)-like syndromes, that should be carefully considered in the aetiology of parenchymal lesions. Correct identification of such organisms is hard to obtain, but is crucial to provide patients with adequate diagnose and treatment. Then, this review aims to unearth their airway tropism, as well as their clinical impact as agents of lung disease.

Enterococcus hirae: a zoonotic microorganism in human umbilical cord blood

Enterococcus hirae is rarely collected from man, while it is a common pathogen in mammals and birds. We describe the first isolation of the organism (strain DSM 27815) from human umbilical cord blood (UCB), thus emphasizing the risk of contamination of UCB units for clinical use. In this context, we also highlight the importance of an extensive training of the collecting personnel as to the observance of the disinfection protocol ensuring UCB units sterility.

Insights into Airway Infections by Enterococci: A Review

Enterococcus is an uncommon but emerging agent of upper and lower airway diseases, including sinuses, trachea, bronchi, lung and pleural infections. In particular, pneumonia and thoracic empyema may jeopardize the clinical outcome of compromised, hospitalized hosts, as well as affect outpatients. Treatment may feel the effects of inherent and acquired resistances such organisms show to commonly used drugs, with the spread of glycopeptide/vancomycin resistant enterococci (GRE/VRE, respectively) being of serious concern. With this work, we want to unearth the impact of members of the genus in the ambit of respiratory infections, and to increase the consciousness of their role as resourceful pathogens for human airways. Also, we are revising patents of interest aiming to timely screen GRE and soon provide clinicians with speciation and glycopeptide resistances.

Colonization by multidrug-resistant organisms in long-term care facilities in Italy: a point-prevalence study

OBJECTIVESnTo determine prevalence and risk factors for colonization by multidrug-resistant organisms (MDROs) in long-term care facility (LTCF) residents in Italy. Genotypes of MDRO isolates were investigated.nnnMETHODSnA point-prevalence study was conducted at 12 LTCFs located in four Italian cities (2 February to 14 March 2015). Rectal swabs, faeces and nasal/auxiliary swabs were cultured for extended-spectrum β-lactamase (ESBL)- and/or carbapenemase-producing Enterobacteriaceae, Clostridium difficile and methicillin-resistant Staphylococcus aureus (MRSA) respectively. Antimicrobial susceptibility testing, detection of ESBL and/or carbapenemase genes and molecular typing of MDROs were performed. Risk factors for colonization were determined by univariate and multivariate analysis.nnnRESULTSnA total of 489 LTCF residents aged ≥65xa0years were enrolled. The prevalence of colonization by ESBL-producing Enterobacteriaceae, MRSA and C.xa0difficile was 57.3% (279/487), 17.2% (84/487) and 5.1% (21/409) respectively. Carriage rate of carbapenemase-producing Enterobacteriaceae was 1% (5/487). Being bedridden was a common independent risk factor for colonization by all MDROs, although risk factors specific for each MDRO were identified. ESBL-producing Escherichia coli carriage was associated with the sequence type (ST) 131-H30 subclone, but other minor STs predominated in individual LTCF or in LTCFs located in the same city, suggesting a role for intrafacility or local transmission. Similarly, MRSA from LTCF residents belonged to the same spa types/ST clones (t008/ST8 and t032/ST22) commonly found in Italian acute-care hospitals, but infrequent spa types were recovered in individual LTCFs. The prevalent C.xa0difficile PCR ribotypes were 356/607 and 018, both common in Italian acute-care hospitals.nnnCONCLUSIONSnMDRO colonization is common among residents in Italian LTCFs.

About a bloodstream Corynebacterium striatum isolate

Corynebacterium striatum is often dismissed as a contaminant when cultivated from blood samples; indeed, it is a skin saprophyte that may therefore be introduced into the clinical specimen accidentally. Nevertheless, the organism can be responsible for true bacteraemias, and multidrug resistance spread among nosocomial strains is of increasing concern. Specific criteria for testing have not been defined yet, but we however suggest to report clear resistances (i.e. absence of any inhibition zones with the disc test), in order to try to understand this species behaviour under antibiotic exposure. In this context, features of a blood isolate (strain DSM 45711) are here depicted.

Consequences of inaccurate hepatitis C virus genotyping on the costs of prescription of direct antiviral agents in an Italian district

Available commercial assays may yield inaccurate hepatitis C virus (HCV) genotype assignment in up to 10% of cases. We investigated the cost-effectiveness of re-evaluating HCV genotype by population sequencing, prior to choosing a direct acting antiviral (DAA) regimen. Between March and September 2015, HCV sequence analysis was performed in order to confirm commercial LiPA-HCV genotype (Versant® HCV Genotype 2.0) in patients eligible for treatment with DAAs. Out of 134 consecutive patients enrolled, sequencing yielded 21 (15.7%) cases of discordant results. For three cases of wrong genotype assignment, the putative reduction in efficacy was gauged between 15% and 40%. Among the eight cases for whom G1b was assigned by commercial assays instead of G1a, potentially suboptimal treatments would have been prescribed. Finally, for five patients with G1 and indeterminate subtype, the choice of regimens would have targeted the worst option, with a remarkable increase in costs, as in the case of the four mixed HCV infections for whom pan-genotypic regimens would have been mandatory. Precise assignment of HCV genotype and subtype by sequencing may, therefore, be more beneficial than expected, until more potent pan-genotypic regimens are available for all patients.

Tinea incognito Caused by Microsporum gypseum in a Patient with Advanced HIV Infection: A Case Report.

The prevalence and the clinical relevance of dermatophytoses in HIV-infected patients are poorly documented, particularly for those caused by tinea incognito. Here, we report a case of widespread facialtinea incognito occurring in an Italian patient with advanced HIV infection, showing both skin and brain lesions. Second-line treatment with liposomal amphotericin B and cotrimoxazole, administered after a microbiological characterization of the skin scrapings, led to complete clearance of all lesions.

Arginine dehydrolase and β-gentiobiose cannot discriminate within the Staphylococcus intermedius group.

Staphylococcus intermedius [SI], Staphylococcus pseudinrmedius [SP] and Staphylococcus delphini [SD] belong to e so-called ‘Staphylococcus intermedius group (SIG)’; they habit various animal species and have been well known be responsible for skin and postoperative infections in ts and dogs (SI, SP), enteritis in minks (SD), and human seases (Sledge et al., 2010; Sasaki et al., 2007; Stegmann al., 2010). In this context, we have read with great interest the ork of Devriese et al. (2009) that has been recently blished on Veterinary Microbiology. Of course, this per contains relevant messages for readers, as it phasizes the risk of misidentifying SIG species unless olecular tools are employed. Especially, authors highht that tuf, sodA and hsp60 gene sequencing may provide liable characterization at a species level, whereas 16S NA analysis may fail to distinguish among such closely lated species (Devriese et al., 2009). Nonetheless, authors state that some phenotypical pects may aid to characterize SI, SP and SD isolates; in is ambit, we do not agree with the assessment that bntiobiose acidification and arginine dehydrolase activity ay discriminate among SI, SP and SD (Devriese et al., 09). Particularly, in the cited paper it is stated that, unlike both SP and SD, SI acidifies b-gentiobiose but fails to exert an arginine dehydrolase activity; conversely, Chuang et al. describe SP as lacking arginine dehydrolase activity (Chuang et al., 2010); again, although supporting the failure of SP to acidify b-gentiobiose (in agreement with the Devriese’s paper), Sasaki et al. report 60% SD strains (group B) as able to determine b-gentiobiose acidification, as well as 20% SD isolates as arginine dehydrolase negative (group B) (Sasaki et al., 2007). The mentioned discrepancies emerging from the published literature are summarized in Table 1. To conclude, it is clear from the published papers that biochemical features may vary among isolates of the same SIG species. Should b-gentiobiose acidification and arginine dehydrolase be considered as discriminating tests, isolates belonging to different species could be confused each other. On the contrary, gene analyses must always be performed, aiming to more deeply understand the phylogeny, epidemiology and pathogenicity of SI, SP and SD, as well as physiological variation of biochemical activities among different strains of these species. Therefore, discrimination among SIG members may not rely on phenotype-based methodologies but can be provided by accurate molecular diagnostics only.

Rapid and persistent selection of the K103N mutation as a majority quasispecies in a HIV1-patient exposed to efavirenz for three weeks: a case report and review of the literature

IntroductionSelection of the K103N mutation is associated with moderately reduced in vitro fitness of HIV. Strains bearing K103N in vivo tend to persist, even in the absence of additional drug pressure, as minority quasispecies, often undetectable in genotyping resistance testing assays, performed at standard conditions. Here, we report on the rapid and long lasting selection of a K103N bearing strain as the dominant quasispecies after very short exposure to efavirenz in vivo.Case presentationA 55-year-old Caucasian man was switched to efavirenz, zidovudine and lamivudine in February 2003, while on viral suppression in his first-line highly active anti-retroviral treatment regimen. One month later, he reported inconsistent adherence and his viremia level was 5700 c/mL. He did not attend further checkups until September 2005, when his viral load was 181,000 c/mL. The patient reported interrupting his medications approximately three weeks after simplification. The genotyping resistance testing assay was performed both on HIV RNA and HIV DNA from plasma, yielding an identical pattern with the isolate presence of the K103N mutation in the prevalent strain.ConclusionPersistence of the K103N mutation as a majority quasispecies may ensue after a very short exposure to efavirenz. Our case would therefore suggest that the presence of the K103N mutation should always be ruled out by genotyping resistance testing assays, even after minimal exposures to efavirenz.