Epidemiology and microbiological features of anaerobic bacteremia in two French University hospitals.

Bacteremia implicating anaerobic bacteria (BIAB) represents 2-6% of all episodes of bacteremia and is associated with high mortality. In this retrospective study from June 2015 to December 2016, we compared BIAB frequency in two hospital centers in Montpellier (France): Montpellier university hospital (MUH) and a center specialized in cancer (ICM). Among the 2465 microbiologically relevant episodes of bacteremia, we identified 144 (5.8%) in which anaerobic bacteria were implicated. BIAB frequency was higher at ICM than MUH (10.4%, vs. 4.9%, p < 0.01). Poly-microbial bacteremia was more frequent among the BIAB episodes (31.9% vs. 11.0% for aerobic-only bacteremia, p < 0.01). Bacteroides and Clostridium were the most frequently identified genera of anaerobic bacteria (64 and 18 episodes, respectively), with the B. fragilis group (BFG) involved in 68/144 episodes. We could perform antibiotic susceptibility typing in 106 of the 144 anaerobic isolates, including 67 BFG isolates. All isolates but one were susceptible to metronidazole. In the BFG, sporadic resistant or intermediate results were found for amoxicillin-clavulanate (5/67), piperacillin-tazobactam (2/67) and imipenem (1/67). BFG isolates were susceptible also to cefoxitin (90.8%), rifampicin (97.0%) and tigecyclin (91.0%). Multidrug resistance in this group (7 isolates) was mostly due to acquired resistance to moxifloxacin, clindamycin and tigecyclin. This study shows that BIAB frequency can vary among hospitals and services. They should especially be taken into account in centers specialized in cancer treatment. However, the implicated bacteria remain frequently susceptible to the most used antibiotics used against anaerobic bacteria, although resistance does exist.

Transmission of IMI-2 carbapenemase-producing Enterobacteriaceae from river water to human.

OBJECTIVES: Carbapenemase-producing Enterobacteriaceae (CPE) are increasing worldwide in human infections. The role of rivers as reservoirs is highlighted, but transmission from the environment to humans is not documented. A human case of bacteraemia caused by IMI-2 carbapenemase-producing Enterobacter asburiae following massive river water exposure underwent microbiological investigations with the aim of deciphering the origin and mechanism of infection. METHODS: Clinical and environmental bacterial strains were compared by resistotyping and genomotyping using pulsed-field gel electrophoresis (PFGE). PFGE was also used to determine the location of the blaIMI-2 carbapenemase gene. The patient's microbiota and river bacterial communities were compared by fingerprinting using 16S rRNA gene PCR-temporal temperature gel electrophoresis. RESULTS: Enterobacter asburiae causing bacteraemia carried the same plasmidic blaIMI-2 gene as E. asburiae strains detected in river water 1 month later. Clinical and river strains displayed identical PFGE profiles. Community fingerprinting showed the persistence in the patient's microbiota of carbapenem-resistant bacteria, which were also autochthonous in the river community (E. asburiae, Aeromonas veronii and Pseudomonas fluorescens). CONCLUSION: Here we have identified for the first time the presence of an IMI-2-producing E. asburiae in a river in the South of France and suggest transmission from the river to a human probably following intestinal translocation. General insights into transmission of CPE from the environment to humans are gained from this case. Considering the rapid spread of CPE in humans, the risk of transfer from an environmental reservoir to human microbiota should be thoroughly investigated at least by implementing environmental surveillance of carbapenem resistance.

Clinical sources and antimicrobial susceptibility of Prevotella timonensis at the university hospital of Montpellier, France.

We describe 84 clinical isolates of Prevotella timonensis recovered between January 2007 and November 2016 at the University Hospital of Montpellier. They were recovered from a variety of clinical samples, mostly of genital and wound origins. All isolates were isolated from a mixed aerobic and anaerobic microbiota. Antimicrobial susceptibility testing of 50 isolates showed 56% of beta-lactamase production and 40% of resistance to clindamycin. One strain was resistant to metronidazole.

VIM-1 carbapenemase-producing Escherichia coli in gulls from southern France.

Acquired carbapenemases currently pose one of the most worrying public health threats related to antimicrobial resistance. A NDM-1-producing Salmonella Corvallis was reported in 2013 in a wild raptor. Further research was needed to understand the role of wild birds in the transmission of bacteria resistant to carbapenems. Our aim was to investigate the presence of carbapenem-resistant Escherichia coli in gulls from southern France. In 2012, we collected 158 cloacal swabs samples from two gull species: yellow-legged gulls (Larus michahellis) that live in close contact with humans and slender-billed gulls (Chroicocephalus genei) that feed at sea. We molecularly compared the carbapenem-resistant bacteria we isolated through culture on selective media with the carbapenem-susceptible strains sampled from both gull species and from stool samples of humans hospitalized in the study area. The genes coding for carbapenemases were tested by multiplex PCR. We isolated 22 carbapenem-resistant E. coli strains from yellow-legged gulls while none were isolated from slender-billed gulls. All carbapenem-resistant isolates were positive for blaVIM-1 gene. VIM-1-producing E. coli were closely related to carbapenem-susceptible strains isolated from the two gull species but also to human strains. Our results are alarming enough to make it urgently necessary to determine the contamination source of the bacteria we identified. More generally, our work highlights the need to develop more bridges between studies focusing on wildlife and humans in order to improve our knowledge of resistant bacteria transmission routes.

High Prevalence of SXT/R391-Related Integrative and Conjugative Elements Carrying blaCMY-2 in Proteus mirabilis Isolates from Gulls in the South of France.

The genetic structures involved in the dissemination of blaCMY-2 carried by Proteus mirabilis isolates recovered from different gull species in the South of France were characterized and compared to clinical isolates. blaCMY-2 was identified in P. mirabilis isolates from 27/93 yellow-legged gulls and from 37/65 slender-billed gulls. It was carried by a conjugative SXT/R391-like integrative and conjugative element (ICE) in all avian strains and in 3/7 human strains. Two clinical isolates had the same genetic background as six avian isolates.

Sacroiliitis secondary to catheter-related bacteremia due to Mycobacterium abscessus (sensu stricto).

We describe a case of sacroiliitis secondary to catheter-related bacteremia due to Mycobacterium abscessus (sensu stricto). This case confirms that MultiLocus sequence typing and variable-number tandem-repeat methods are very robust techniques to identify the pathogen species and to validate molecular epidemiological links among complex M. abscessus isolates.

Comparison of isotopic and immunoenzymatic methods for folate and vitamin B12 determination.

BACKGROUND: The objective of this study was to compare automated immunoenzymatic assay (IEA) with an isotopic reference method for determination of plasma folate, erythrocyte folate, and plasma vitamin B12 levels. METHODS: Analytical performance including within-run and between-run imprecision was assessed on the automated IEA on the Access2 (Beckman Coulter, France). Folate and B12 levels determined routinely with a radioimmunoassay (RIA) (Simultrac, Diasorin, Italy) using EDTA samples (n=100) were compared to the Access2 IEA. To evaluate pre-analytical conditions, EDTA and heparinized plasma (n=56) from simultaneous samplings were used to compare folate and B12 levels via RIA and the Access2. In addition, discordant results were assayed by IEA on the Architect i2000 (Abbott, France). RESULTS: Coefficient of variation for folate and B12 measurements on the Access2 ranged between 1.5% and 4.1%, respectively, for within-run assays, while between-run imprecision ranged from 4.8% to 9.3%, respectively. Comparison of RIA (x) and IEA on the Access2 (y) using EDTA samples showed a good correlation for plasma folate (y = 0.94x + 1.09; r2 = 0.83), acceptable correlation for erythrocyte folate (y = 0.65x + 137; r2 = 0.57) and discrepancy for B12 (y = 0.67x + 211; r2 = 0.37). This discordance for vitamin B12 was not observed when comparing RIA (x) and IEA on the Architect i2000 (y) (y = 0.74x + 40; r2 = 0.92) and disappeared when using heparinized samples for the Access2 (y = 0.85x + 7.05; r2 = 0.90). CONCLUSIONS: Automated IEA appears to be a good alternative to RIA for the determination of folate and vitamin B12 but requires the use of an adequate anticoagulant.