First description of NDM-1-positive Klebsiella pneumoniae in the Tunisian community

First description of NDM-1-positive Klebsiella pneumoniae in the Tunisian community Sir, Multidrug-resistant bacteria, especially carbapenemase-producing Enterobacteriaceae, are a major public health-threat worldwide. As part of a collaborative monitoring programme, our laboratory at the University of Bordeaux has received a collection of multidrug-resistant bacterial strains to further characterise their β-lactamase content. They were sent from private Tunisian diagnostic laboratories and were collected from community patients suffering from urinary tract infection. In this context, multidrug-resistant isolate 18TA was collected in January 2018 in Sfax region from the urine of a 45-year old female with no previous hospitalisation during the preceding month and no history of recent foreign travel. Strain 18TA had been initially classified as Enterobacter spp. by biochemical tests (API 10S gallery). Following matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF/MS) (Bruker Daltonics) and confirmation by PCR amplification and sequencing of 16S rDNA, strain 18TA was re-identified as Klebsiella pneumoniae. Multilocus sequence typing (MLST) (http:// bigsdb.pasteur.fr/klebsiella/klebsiella.html) indicated that strain 18TA belonged to Sequence Type (ST), ST147. Minimum inhibitory concentrations (MICs) of various anti-microbials were determined using a BD Phoenix TM 100 automated system (BD Diagnostic Systems, Le Pont-de-Claix, France) and the results were interpreted using BD EpiCenter TM software (BD Diagnostic Systems). The MICs for ciprofloxacin and colistin were also determined by the broth microdilution method according to European Committee on Antimicrobial Susceptibility Testing 2019 guidelines (https://www.sfm-microbiologie.org/2019/05/06/ casfm-eucast-2019-v2/). Strain 18TA was resistant to all tested β-lactams, including carbapenems (Table 1). The strain was also resistant to gentamicin, tobramycin, quinolones (nalidixic acid), fluoroquinolones (cipro-floxacin) and trimethoprim/sulfamethoxazole (SXT) and showed decreased susceptibility to tigecycline (MIC = 2 mg/mL). It remained susceptible to amikacin, fosfomycin and colistin (Table 1). The imipenem/ethylene diamine tetra-acetic acid (EDTA) combined disk diffusion test was positive since the inhibition zone increased by 7 mm with the imipenem/EDTA disk compared with the imipenem disk alone, suggesting the presence of a metallo-β-lactamase (MBL) [1]. In addition, the double-disk synergy test (between amoxicillin/clavulanic acid and broad-spectrum cepha-losporins) showed the presence of an extended-spectrum β-lactamase (ESBL)-producing phenotype (data not shown). The transferability of the β-lactam resistance determinant was assessed by conjugation assay using an azide-resistant (Az R) mutant of Escherichia coli C600 as the recipient strain. Selection was performed on Mueller-Hinton agar plates supplemented with sodium azide (300 mg/mL) and ertapenem (4 mg/mL). A transfer frequency of ca. 10-4 transconjugants per donor was observed. Comparison of MICs between the transconjugant (Tc-18TA) and its recipient strain (C600 Az R) showed increased resistance not only to the tested β-lactams but also to gentamicin, tobramycin and SXT (Table 1). Total genomic DNA of strain 18TA was screened using different multiplex PCR amplifications for various β-lactamase genes (bla TEM-like , bla SHV-like , bla OXA-1-like , bla CTX-M groups 1, 2, 9, 18 and 25, bla OXA-48-like , bla KPC and bla GES and the MBL genes bla VIM , bla IMP and bla NDM) as described previously [2]. Amplification results following agarose gel electrophoresis analysis showed the presence of group 1 bla CTX-M and bla NDM genes together with bla TEM-like , bla SHV-like and bla OXA-1-like genes. Except for the bla SHV gene that was found in strain 18TA but not in the transconjugant Tc-18TA and that was attributed to the chromosomally-encoded species-specific enzyme of K. pneumoniae, the four other β-lactamases were also found in transconjugant Tc-18TA (Table 1). Amplification of the entire bla genes was performed and subsequent sequencing ((Custom DNA sequencing; Eurofins Genomics GmbH, Ebersberg, Germany) showed the presence of the narrow-spectrum β-lactamase genes bla TEM-1B and bla OXA-1 associated with the bla CTX-M-15 ESBL gene and the bla NDM-1 MBL gene both in 18TA and Tc-18TA (Table 1). Furthermore, amplifications searching for aac(3)-IIa (gentamicin and tobramycin resistance) and sul1 and dfrA1 (sulfamethoxazole and trimetho-prim resistance, respectively) were positive both in 18TA and Tc-18TA. These genes were also present in Kp3771, a ST147 NDM-1-producing K. pneumoniae strain recently recovered from a patient hospitalised in an intensive care unit of University Hospital Tahar Sfar in Tunisia [3]. NDM-1-positive K. pneumoniae strains have been previously described in Tunisia, but only from hospitalised patients [1-5]. The current study reports the first description of K. pneumoniae carrying the carbapenemase NDM-1 in the Tunisian community http://dx

Is systematic fecal carriage screening of extended-spectrum beta-lactamase-producing Enterobacteriaceae still useful in intensive care unit: a systematic review

Abstract Background Extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) are disseminating worldwide leading to increased hospital length of stay and mortality in intensive care units (ICU). ESBL-E dissemination was first due to outbreaks in hospital settings which led to the implementation of systematic fecal carriage screening to improve hygiene procedures by contact precautions. ESBLs have since spread in the community, and the relevance of contact precautions is questioned. ESBL-E dissemination led to an overuse of carbapenems triggering the emergence of carbapenem-resistant Enterobacteriaceae. Empirical antimicrobial therapy based on ESBL-E fecal carriage has been proposed but is debated as it could increase the consumption of carbapenems among ESBL-E carriers without any clinical benefit. Finally, selective decontamination among ESBL-E fecal carriers is evoked to decrease the risk for subsequent ESBL-E infection, but its efficacy remains debated. We propose to systematically review the evidence to recommend or not such systematic ESBL-E fecal carriage screening in adult ICU. Methods Every article focusing on ESBL-E and ICU available on the MEDLINE database was assessed. Articles were included if focusing on cross-transmission, efficacy of hygiene procedures, link between ESBL-E colonization and infection or guidance of empirical therapy or selective decontamination efficacy. Results Among 330 articles referenced on PubMed, 39 abstracts were selected for full-text assessment and 25 studies were included. Systematic screening of ESBL-E fecal carriage to guide contact precautions do not seem to decrease the rate of ESBL-E cross-transmission. It has a very good negative predictive value for subsequent ESBL-E infections but a positive predictive value between 40 and 50% and so does not help to spare carbapenems. Cessation of ESBL-E carriage systematic screening could decrease the use of carbapenems in ICU without any clinical harm. Nevertheless, further studies are needed to validate these results from monocentric before-after study. Selective decontamination strategy applied to ESBL-E fecal carriers could be helpful, but available data are conflicting. Conclusion Current knowledge lacks of high-quality evidence to strongly recommend in favor of or against a systematic ESBL-E fecal carriage screening policy for ICU patients in a non-outbreak situation. Further evaluation of selective decontamination or fecal microbiota transplantation among ESBL-E fecal carriers is needed

Detection of Clones B2-ST131-C2 and A-ST617 in Escherichia coli Producing Both CTX-M-15 and CTX-M-27 from Tunisian Community Patients

During a two-month period (2017–2018), 336 urine samples positive for Escherichia coli were collected from Tunisian patients. Of the 336 samples, 266 were collected from community patients and 70 from hospital settings. In all, 15 ESBL producers were identified (8 and 7, respectively) and assigned to 13 pulsotypes, including four ESBL-producing E. coli (ESBL-E) with E1 and E2 profiles (2 isolates each) from community patients. The two strains E1 were identified as B2-ST131 subclade C2 and the two isolates E2, A-ST617. The four strains carrying both CTX-M-15 and CTX-M-27, exhibited the multireplicon IncFII/F1A/F1B with the same formula F31:A4:B1. Two isolates with patterns E3 and E4 (Dice coefficient, 78.7%) isolated from community and hospital settings of two geographic areas were assigned to the emerging ST131 C1-M27 subclade and contained the replicon F1:A-:B20. The remaining ESBL-E divided into different sequence types/associated CTX-M: 2 ST131-C2/CTX-M-15 and ST744/CTX-M-55, ST617/CTM-15, ST2973/CTX-M-55, ST6448/CTX-M-15, ST224/CTX-M-15, ST1431/CTX-M-15, and ST38/CTX-M-27, one isolate each. Our study reports for the first time the presence in the Tunisian community of two clones of E. coli, including the virulent clone ST131-C2 harboring both CTX-M-15 and CTX-M-27, and confirms the spread of the emergent clone ST131-C1-M-27, notably in community urinary tract infections

Bridging gut microbiota composition with extended-spectrum beta-lactamase Enterobacteriales faecal carriage in critically ill patients (microbe cohort study)

Abstract Background The worldwide dissemination of extended spectrum beta-lactamase producing Enterobacteriales (ESBL-E) is of major concern. Microbiota may play a role in the host resistance to colonization with ESBL-E, but the underlying mechanisms remain unknown. We aimed to compare the gut microbiota composition between ESBL-producing E. coli or K. pneumoniae carriers and ESBL-E non-carriers according to the bacterial species. Results Among 255 patients included, 11 (4,3%) were colonized with ESBL-producing E. coli and 6 (2,4%) with ESBL-producing K. pneumoniae, which were compared with age- and sex-matched ESBL-E non carriers. While no significant differences were found between ESBL-producing E. coli carriers and non-carriers, gut bacteriobiota α-diversity was decreased in ESBL-K. pneumoniae faecal carriers compared both with non-carriers (p = 0.05), and with ESBL-producing E. coli carriers. The presence of Sellimonas intestinalis was associated with the absence of ESBL-producing E. coli fecal carriage. Campylobacter ureolyticus, Campylobacter hominis, bacteria belonging to Clostridium cluster XI and Saccharomyces sp. were associated with the absence of ESBL-producing K. pneumoniae faecal carriage. Conclusions The composition of the gut microbiota differs between ESBL-producing E. coli and K. pneumoniae faecal carriers suggesting that microbial species should be taken into account when investigating the role of gut microbiota in resistance to gut colonization with ESBL-E. Trial registration number: NCT04131569, date of registration: October 18, 2019

Polymicrobial Infections Among Patients with Vascular Q Fever, France, 2004–2020

International audienceWe report 5 cases of vascular Q fever complicated by polymicrobial superinfection in patients who had no risk factors for acute Q fever. Q fever was diagnosed by serologic and molecular assays for Coxiella burnetii. We confirmed additional infections using conventional graft cultures

Néphrologie & Thérapeutique

La population de patients traités par hémodialyse sur cathéter est fragile, à risque infectieux important. La bactériémie liée au cathéter d’hémodialyse est l’une des complications les plus graves, dont l’incidence augmente chaque année, en lien avec une hausse de l’utilisation des cathéters comme abord vasculaire. Cependant, le diagnostic clinique et microbiologique reste difficile. La mise en place de l’antibiothérapie probabiliste se base sur des recommandations anciennes qui préconisent d’associer une molécule visant le Staphylococcus aureus méticillino-résistant, ainsi qu’une bêtalactamine active sur P. aeruginosa, mais également d’adapter ce traitement probabiliste en réalisant un recueil microbiologique à l’échelle locale, ce qui est rarement réalisé. Dans notre centre d’hémodialyse du CHU de Bordeaux, une analyse de la répartition bactériologique des bactériémies liées au cathéter d’hémodialyse sur la période 2018–2020 a permis de proposer, en accord avec les infectiologues, un protocole d’antibiothérapie probabiliste adaptée. Cette démarche nous a permis de constater une incidence faible de méticillino-résistance des Staphylocoques, une incidence nulle de Staphylocoque après un délai de pose du cathéter de plus de 6 mois, aucun Pseudomonas multirésistant et un très faible pourcentage d’entérobactérie résistant aux céphalosporines. La mise à jour régulière de l’épidémiologie microbiologique des bactériémies liées aux cathéters d’hémodialyse, associée à un partenariat avec l’équipe d’infectiologie dans son centre d’hémodialyse, permettant une adaptation de l’antibiothérapie probabiliste, paraît avoir une bonne faisabilité et, à long terme, favoriser la préservation de l’écologie microbienne à l’échelle individuelle et collective pour la population de patients traités par hémodialyse.Patients in hemodialysis on central venous catheter as vascular access are at risk of infections. Catheter-related bloodstream infection is one of the most serious catheter-complications in hemodialysis patients. Its clinical and microbiological diagnosis is challenging. The implementation of empiric antibiotic therapy is based on old recommendations proposing the combination of a molecule targeting methicillin-resistant Staphylococcus aureus and a betalactamin active on P. aeruginosa, and also adapting this probabilistic treatment by carrying out a microbiological register on a local scale, which is rarely done. In our hemodialysis center at Bordeaux University Hospital, an analysis of the microorganisms causing all catheter-related bloodstream infection over the period 2018–2020 enabled us to propose, in agreement with the infectious disease specialists, an adapted probabilistic antibiotic therapy protocol. This approach allowed us to observe a low incidence of meticillinoresistance of Staphylococcus. For catheters inserted more than 6 months ago, we observed no Staphylococcus, no multi-resistant Pseudomonas, and only 2% of Enterobacteria resistant to cephalosporins. A frequent updating of the microbiological epidemiology of catheter-related bloodstream infection, in partnership with the infectious diseases team in each hemodialysis center, allowing an adaptation of the probabilistic antibiotic therapy, and seems to have a good feasibility. This strategy might favor the preservation of microbial ecology on an individual and collective scale in maintenance hemodialysis patients