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Recent treatment guidelines for uncomplicated urinary tract infections (UTIs) discourage fluoroquinolone prescription because of collateral damage to commensal microbiota, but the ecologic impact of alternative agents has not been evaluated by culture-free techniques. We prospectively collected faecal samples at three time points from ambulatory patients with UTIs treated with ciprofloxacin or nitrofurantoin, patients not requiring antibiotics and household contacts of ciprofloxacin-treated patients. We described changes in gut microbiota using a culture-independent approach based on pyrosequencing of the V3-V4 region of the bacterial 16S rRNA gene. All groups were similar at baseline. Ciprofloxacin had a significant global impact on the gut microbiota whereas nitrofurantoin did not. The end of ciprofloxacin treatment correlated with a reduced proportion of Bifidobacterium (Actinobacteria), Alistipes (Bacteroidetes) and four genera from the phylum Firmicutes (Faecalibacterium, Oscillospira, Ruminococcus and Dialister) and an increased relative abundance of Bacteroides (Bacteroidetes) and the Firmicutes genera Blautia, Eubacterium and Roseburia. Substantial recovery had occurred 4 weeks later. Nitrofurantoin treatment correlated with a reduced relative proportion of the genus Clostridium and an increased proportion of the genus Faecalibacterium. This study supports use of nitrofurantoin over fluoroquinolones for treatment of uncomplicated UTIs to minimize perturbation of intestinal microbiota.

New Delhi metallo-␤-lactamase (NDM-1) was initially identified in various Enterobacteriaceae and recently in Acinetobacter baumannii. This study described the clonal dissemination of an NDM-2-producing A. baumannii isolate in an Israeli rehabilitation ward and the genetic surroundings of the gene. The bla NDM-2 gene was surrounded by the ble and trpF genes downstream and two copies of the ISAba125 on both sides. These are the first NDM-producing A. baumannii strains in Israel from patients with no previous travel or hospitalization on the Indian subcontinent.Carbapenem resistance in Gram-negative bacteria is an important worldwide problem, particularly because of the production of class A, D, and B metallo-␤-lactamase enzymes (MBLs) as a resistance mechanism and the facility to spread by mobile genetic elements (12). The new MBL, New Delhi metallo-␤-lactamase 1 (NDM-1), initially reported in Klebsiella pneumoniae and Escherichia coli recovered from a Swedish patient who was previously hospitalized in India (23), has disseminated to several countries and other Enterobacteriaceae (4,9,13,(15)(16)(17)(18)22). Recently, cases of NDM-producing Acinetobacter baumannii have been described in India, Egypt, and China (1, 6, 8).Five carbapenem-resistant A. baumannii isolates were recovered from female patients at the TA-Sourasky-MA Rehabilitation hospital in Tel Aviv, Israel (Table 1). The five elderly patients (mean age, 81) were hospitalized in the same geriatric rehabilitation ward. The cultures were taken as a point prevalence study from 70 patients hospitalized in two wards in the rehabilitation center. Surveillance skin cultures were taken from six body sites (armpit, thigh, and groin, bilaterally). Four of the five patients were admitted to rehabilitation after orthopedic surgery in two different orthopedic wards located in the same hospital, adjacent to the rehabilitation center. Three of the patients shared a room with each other at a point during their hospital stay, and others shared with them common facilities. None of the patients had any clinical culture that grew Acinetobacter spp., and no signs of infection due to Acinetobacter were evident. There was no specific history taken regarding travel (Table 1). Isolates were initially identified using the Vitek-2 automatic system (bioMérieux, Marcy, France) and confirmed by amplified rRNA gene restriction analysis (ARDRA) (20). The epidemiological relationship was corroborated by pulsed-field gel electrophoresis (PFGE) under conditions described elsewhere (10). PFGE results showed an identical pattern for all the strains. Multiplex PCR to identify clonal lineages (19) showed that the strains did not belong to pan-European clone I, II, or III. Multilocus sequence typing (MLST) indicated that the strain corresponded to sequence type (ST) 103 according to the Pasteur system (http://www.pasteur.fr /recherche/genopole/PF8/mlst/Abaumannii.html), which is in agreement with the ST found in the NDM-2-producing A. baumannii isolate reported from Egypt (6).Antibiotic suscep...

The prospective project MOSAR was conducted in five rehabilitation units: the Berck Maritime Hôpital (Berck, France), Fondazione Santa Lucia (Rome, Italy), Guttmann Institute (GI; Barcelona, Spain), and Loewenstein Hospital and Tel-Aviv Souraski Medical Center (TA) (Tel-Aviv, Israel). Patients were screened for carriage of Enterobacteriaceae resistant to expanded-spectrum cephalosporins (ESCs) from admission until discharge. The aim of this study was to characterize the clonal structure, extendedspectrum ␤-lactamases (ESBLs), and acquired AmpC-like cephalosporinases in the Escherichia coli populations collected. A total of 376 isolates were randomly selected. The overall number of sequence types (STs) was 76, including 7 STs that grouped at least 10 isolates from at least three centers each, namely, STs 10, 38, 69, 131, 405, 410, and 648. These clones comprised 65.2% of all isolates, and ST131 alone comprised 41.2%. Of 54 STs observed only in one center, some STs played a locally significant role, like ST156 and ST393 in GI or ST372 and ST398 in TA. Among 16 new STs, five arose from evolution within the ST10 and ST131 clonal complexes. ESBLs and AmpCs accounted for 94.7% and 5.6% of the ESC-hydrolyzing ␤-lactamases, respectively, being dominated by the CTX-M-like enzymes (79.9%), followed by the SHV (13.5%) and CMY-2 (5.3%) types. CTX-M-15 was the most prevalent ␤-lactamase overall (40.6%); other ubiquitous enzymes were CTX-M-14 and CMY-2. Almost none of the common clones correlated strictly with one ␤-lactamase; although 58.7% of ST131 isolates produced CTX-M-15, the clone also expressed nine other enzymes. A number of clone variants with specific pulsed-field gel electrophoresis and ESBL types were spread in some locales, potentially representing newly emerging E. coli epidemic strains.

Extended-spectrum b-lactamaseIncidence rate Machine learning a b s t r a c t Objectives: The aim of the study was to measure the impact of antibiotic exposure on the acquisition of colonization with extended-spectrum b-lactamase-producing Gram-negative bacteria (ESBL-GNB) accounting for individual-and group-level confounding using machine-learning methods. Methods: Patients hospitalized between September 2010 and June 2013 at six medical and six surgical wards in Italy, Serbia and Romania were screened for ESBL-GNB at hospital admission, discharge, antibiotic start, and after 3, 7, 15 and 30 days. Primary outcomes were the incidence rate and predictive factors of new ESBL-GNB colonization. Random forest algorithm was used to rank antibiotics according to the risk of selection of ESBL-GNB colonization in patients not colonized before starting antibiotics. Results: We screened 10 034 patients collecting 28 322 rectal swab samples. New ESBL-GNB colonization incidence with and without antibiotic treatment was 22/1000 and 9/1000 exposure-days, respectively. In the adjusted regression analyses, antibiotic exposure (hazard ratio (HR) 2.38; 95% CI 1.29e4.40), age 60 e69 years (HR 1.19; 95% CI 1.05e1.34), and spring season (HR 1.25; 95% CI 1.14e1.38) were independently associated with new colonization. Monotherapy ranked higher als combination therapy in promoting ESBL-GNB colonization. Among monotherapy, cephalosporins ranked first followed by tetracycline (second), macrolide (fourth) and cotrimoxazole (seventh). Overall the ranking of cephalosporins was lower when used in combination. Among combinations not including cephalosporins, quinolones plus carbapenems ranked highest (eighth). Among sequential therapies, quinolones ranked highest (tenth) when prescribed within 30 days of therapy with cephalosporins. Conclusions: Impact of antibiotics on selecting ESBL-GNB at intestinal level varies if used in monotherapy or combination and according to previous antibiotic exposure. These finding should be explored in future clinical trials on antibiotic stewardship interventions.