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

OBJECTIVES

To 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.

METHODS

A 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.

RESULTS

A total of 489 LTCF residents aged ≥65 years were enrolled. The prevalence of colonization by ESBL-producing Enterobacteriaceae, MRSA and C. difficile 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. difficile PCR ribotypes were 356/607 and 018, both common in Italian acute-care hospitals.

CONCLUSIONS

MDRO colonization is common among residents in Italian LTCFs.

Corynebacterium glucuronolyticum causing genitourinary tract infection: Case report and review of the literature

Corynebacterium species are increasingly recognized as opportunistic pathogens. A growing number of taxonomic studies has yielded a description of numerous new Corynebacterium species, such as those related to the urogenital tract, with Corynebacterium glucuronolyticum found to be rarely involved in genitourinary tract infections, particularly in male individuals. In this report, we describe a urethritis case caused by C. glucuronolyticum in a 37-year-old, apparently healthy male, who complained mild pain in the lower abdomen, with several urinary symptoms. While urethral and semen specimens did not yield positive results for microbiological evaluation, cultures of urine samples revealed the monomicrobial growth on blood-containing media of tiny colonies after 24 h of incubation, clearly evident only after 48 h of incubation under CO2-enriched atmosphere. Colonies were identified as C. glucuronolyticum both by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) and 16S rRNA gene sequencing. Oral ciprofloxacin gradually led to clinical improvement and, finally, to a complete recovery, in accordance with microbiological findings. In spite of its infrequent detection, C. glucuronolyticum might be a potential urogenital pathogen in males more commonly that what believed, perhaps due to slow growth leading to underrecognition; we suggest therefore to consider the organism in the differential diagnostics of bacterial diseases of the urinary tract.

Subinhibitory concentrations of moxifloxacin decrease adhesion and biofilm formation of Stenotrophomonas maltophilia from cystic fibrosis

Stenotrophomonas maltophilia is an emerging nosocomial bacterial pathogen that is currently isolated with increasing frequency from the airways of cystic fibrosis (CF) patients. In this study the effect of subinhibitory concentrations (subMICs) of moxifloxacin on adhesion, biofilm formation and cell-surface hydrophobicity of two strains of S. maltophilia isolated from CF patients were evaluated. Adhesion and biofilm formation assays were carried out on polystyrene and quantified by colony counts. Cell-surface hydrophobicity was determined by a test for adhesion to n-hexadecane. Moxifloxacin at 0.03× and 0.06× MIC caused a significant decrease in adhesion and biofilm formation by both strains tested. A significant reduction in cell-surface hydrophobicity following exposure to subMICs of moxifloxacin was observed for one strain only. The results of the present study provide an additional rationale for the use of moxifloxacin in CF patients and more generally in biofilm-related infections involving S. maltophilia.

Addition of Teicoplanin or Vancomycin for the Treatment of Documented Bacteremia due to Gram-Positive Cocci in Neutropenic Patients with Hematological Malignancies: Microbiological, Clinical and Economic Evaluation

A prospective, randomized, double-blind trial was conducted on 124 febrile patients with hematological malignancies to compare teicoplanin with vancomycin as an addition to the initial empiric amikacin-ceftazidime regimen after documented bacteremia due to gram-positive cocci. At enrollment, patients in both groups were comparable with respect to age, sex, underlying hematologic disorders and duration of neutropenia. Rates of therapeutic success were 55/63 (87.3%) in the teicoplanin group and 56/61 (91.8%) in the vancomycin group (p = 0.560). The mean duration of treatment was similar, being 12.2 and 11.4 days, respectively (p = 0.216). Patients treated with teicoplanin remained febrile for slightly longer than those treated with vancomycin (4.9 vs. 4.0 days) (p = 0.013). Thirteen patients experienced an adverse drug reaction, but without any significant difference in the two arms. Isolated staphylococci showed a progressive and significant decrease in susceptibility to both glycopeptides during the 8 study years. The economic analysis performed showed that the addition of vancomycin is cost-saving.