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Six strains of a rapidly growing scotochromogenic mycobacterium were isolated from pulmonary specimens of independent patients. Biochemical and cultural tests were not suitable for their identification. The mycolic acid pattern analysed by HPLC was different from that of any other mycobacterium. Genotypic characterization, targeting seven housekeeping genes, revealed the presence of microheterogeneity in all of them. Different species were more closely related to the test strains in various regions: the type strain of Mycobacterium moriokaense showed 99.0 % 16S rRNA gene sequence similarity, and 91.5–96.5 % similarity for the remaining six regions. The whole genome sequences of the proposed type strain and that of M. moriokaense presented an average nucleotide identity (ANI) of 82.9 %. Phylogenetic analysis produced poorly robust trees in most genes with the exception of rpoB and sodA where Mycobacterium flavescens and Mycobacterium novocastrense were the closest species. This phylogenetic relatedness was confirmed by the tree inferred from five concatenated genes, which was very robust. The polyphasic characterization of the test strains, supported by the ANI value, demonstrates that they belong to a previously unreported species, for which the name Mycobacterium celeriflavum sp. nov. is proposed. The type strain is AFPC-000207T ( = DSM 46765T = JCM 18439T).

Infection is a common complication in patients carrying a central venous catheter (CVC) and is associated with increased morbidity and mortality. Leclercia adecarboxylata is an unusual but emerging pathogen in healthy and immunocompromised patients. We report a case of L. adecarboxylata bacteraemia in a patient with a haemodialysis tunnelled CVC. In accordance with the susceptibility to the tested antimicrobials, a long-course treatment with intravenous gentamicin plus amoxicillin-clavulanic acid and gentamicin-lock therapy was adopted. The patient had a full recovery and the catheter was not removed. We also performed a systematic PubMed/Medline and Scopus review of peer-reviewed English papers on L. adecarboxylata infections, focusing on bacteraemia in patients with different types of CVCs. Moreover, we suggest a treatment algorithm to preserve the patient and maintain the CVC.

Introduction: The bone and joint infections sustained by mycobacteria and mainly involving the synovium, tendons and bone stock, may be traumatic, especially in open fractures or iatrogenic post surgical procedures. Methods: The frustules, taken after cleaning the bone, were sent to the Microbiological Laboratory and processed for the presence of Gram-positive and Gram-negative bacterial populations, the mycobacteria Group M. tuberculosis complex and the mycobacteria belonging to the group of NTM (Non Tubercular Mycobacteria). Results: The decontaminated material was sown on liquid culture (MGIT 960 System BD Diagnostics) and on solid growth medium (Löwenstein-Jensen) and kept under observation at 37° C for 60 days. After 15 days on the solid medium there developed a mycobacterium strongly pigmented in orange. By the reverse hybridization method “GenoType® CM; Hain Diagnostika, Nehren, Germany; Arnika”, Mycobacterium szulgai was identified, an organism rarely isolated in our laboratory. On preliminary characterization it resulted scotochromogenic at 37° C and photochromogenic when cultured at 25° C. Conclusions: The isolation of M. szulgai, and the previous isolation of a M. intracellular (paper in press) from a similar material suggest that, in this type of infection, the role of mycobacteria can be clinically relevant and probably underestimated, both because the difficulty of isolating and identifying these organisms and because surgeons almost never request this type of investigation. It would therefore be appropriate to send routinely these materials to dedicated laboratories equipped to search for mycobacteria. Its identification could allow a more realistic picture on the role played by these bacterial infections in osteoarticular infections.

From June 2004 to June 2005, a total of 58 mycobacterial isolates were recovered from inpatients admitted to the “Ospedale Maggiore” in Novara, Italy. Most of the above strains were from respiratory secretions. Among the 32 isolates identified as Mycobacterium tuberculosis complex (MTC), susceptibility testing to streptomycin, isoniazid, rifampin, ethambutol and pyrazinamide was subsequently performed by using the MGIT 960 system. Starting from positive cultures, the Genotype MTBDR “Arnika” test, based on target amplification and stripbased reverse hybridization was also carried out. In addition to the MTC identification, the test can investigate the resistance to both rifampin (by molecular analysis of the rpoB region) and isoniazid (by detecting mutations at the resistance domain of katG gene). The results were compared with those obtained by conventional liquid medium susceptibility testing. Full agreement with both drugs was obtained on all the tested isolates. In conclusion, the GenoType MTBDR assay was found to enable a very rapid resistance detection of the most important anti-tubercular drugs.These data are important to set up an effective therapy and consequent disease control.

Central venous catheter represents a major source of nosocomial bloodstream infection, which cause considerable excess morbidity.The diagnosis of catheter-related infections relies on the presence of clinical manifestation of infection and the evidence of colonization of the catheter tip by bacteria or fungi. The most frequent pathogens were Gram-positive organisms, mainly coagulase negative staphylococci, followed by Gram-negative and mycetes. During the years 2001-2003 we examined 2079 vascular catheters, of which 896 were positive for bacterial and fungal species. Of these, 675 (75,3%) involved Gram-positive bacterial, 145 (16,2%) Gram-negative and 76 (8,5%) mycetes.

In thIe latter years Enterobacter cloacae has been counted as a very important occasional pathogen, above all in causing hospital infections.The micro-organism’s interesting increases because of its high resistance in vitro to many antimicrobial agents. For this reason it would be possible to find out others resistance mutant phenotypes. The results (2000-2001 and the first six months of 2002), carried out 341 isolated samples from hospital patients, show that the percentage of these E. cloacae is little more than 1%, increasing prevalence of patients belonging to General Surgery and Intensive Care Unit. The susceptible tests suggest (without important differences during the whole year) that most of the clinical isolates have moderate or high level resistance to various antimicrobial agents (penicillins, cephalosporins, aminoglycosides, quinolones, monobactam) and almost all were susceptible to amikacin, carbapenems (imipenem) and trimethoprim/sulfmamethoxazolo. Always regarding the resistance of these pathogens, it was possible to find out some phenotypes, and one of these, among 172 isolates belonging to Intensive Care Unit, was a particular multiresistance phenotype. The VITEK ESsL detection test and the conventional double disk synergy test for detection of ESsL find out some phenotypes showing expression of stably derepressed beta-lactamase.