Rectal Carriage Research Articles

Interplay of nasal and rectal carriage of Staphylococcus aureus in intensive care unit patients.

The aim of this study was to investigate the relationship between nasal and rectal Staphylococcus aureus carriage in intensive care unit (ICU) patients and the occurrence of ICU-acquired infections related to S. aureus carriage. Three hundred and ninety-five patients admitted in ICU were screened for S. aureus nasal and rectal carriages and followed to record S. aureus infections during their stay. S. aureus strains were genotyped by arbitrarily primed PCR, spa-typing, microarray and whole genome sequencing. At ICU admission, 112 of 363 (30.9%) patients carried S. aureus including 61 (16.8%) exclusive nasal carriers, 40 (11.0%) combined nasal and rectal carriers and 11 (3.0%) exclusive rectal carriers. The 152 S. aureus isolates from nasal and rectal swabs belonged to 19 clonal complexes (CCs). Patients colonized in both nose and rectum harboured different strains in at least 40% of cases according to arbitrarily primed PCR data. Nasal carriers of CC5 S. aureus had an increased risk of rectal carriage (RR = 1.85, P < .05). S. aureus nasal and rectal carriage was a risk factor of S. aureus ICU-acquired infection (RR = 4.04; 95%CI [1.38-11.76]). Incidence rates of endogenous ICU-acquired infections in exclusive nasal carriers, exclusive rectal carriers and in both nasal and rectal carriers were 0.08 (5/61), 0.09 (1/11) and 0.03 (1/40), respectively (p = 0.47). Rectal swabbing increased the detection of S. aureus carriage and revealed an important diversity of S. aureus strains in ICU patients. Further studies are needed to understand how S. aureus rectal carriage increases the risk of endogenous ICU-acquired infections.

Surveillance cultures for detection of rectal and lower respiratory tract carriage of colistin-resistant Gram-negative bacilli in intensive care unit patients: comparison of direct plating and pre-enrichment step.

Purpose. Increasing consumption of colistin as treatment for infections with multidrug-resistant (MDR) Gram-negative bacilli (GNB) has been accompanied by increasingly frequent reports of colistin-resistant (ColR) MDR GNB. Higher selective pressure creates a favourable environment that can facilitate the spread of ColR isolates. Monitoring of asymptomatic ColR GNB carriage can give us a better understanding of this emerging healthcare problem, particularly in wards with higher polymyxin selective pressure and prevalence of carbapenem-resistant GNB. Our aim was to assess the ColR GNB colonization rate in intensive care unit (ICU) patients and evaluate the performance of two surveillance protocols using a selective medium.Methodology. A prospective study included 739 surveillance samples (rectal swabs and tracheal aspirates) from 330 patients that were screened for ColR GNB carriage using SuperPolymyxin medium. Two approaches were used: direct sample plating and overnight pre-enrichment of samples followed by plating. Colistin resistance was confirmed with broth microdilution. ColR isolates were molecularly screened for plasmid-mediated mcr genes.Results. A total of 44/739 samples (45 ColR GNB isolates) were positive for ColR GNB, which included 31/330 (9.4 %) colonized patients; mcr genes were not detected. The direct plating method only identified 17/45 (37.8 %) isolates correctly, whereas the pre-enrichment protocol identified all 45 ColR GNB.Conclusion. The colonization rate among our ICU patients was 9.4 %. Based on our findings, the pre-enrichment step is necessary for the determination of ColR GNB carriage - even though the time to result takes an additional day, fewer than half of ColR GNB carriers were detected using the direct plating protocol.

Accreditation of the screening for the rectal carriage of vanA and/or vanB Vancomycin-resistant enterococci by an accredited laboratory under the standard NF EN ISO/IEC 17025:2005

The quality of the screening of vanA and/or vanB Vancomycin-resistant enterococcal (VRE) carriage by patients transferred from foreign countries plays a role in the management of risks linked to extensively drug resistant organisms (XDRO). Accreditation of the screening according to the NF EN ISO 15189 and NF EN ISO/IEC 17025 standards contributes to satisfy the level of quality. Our laboratory was already accredited according to the NF EN ISO/IEC 17025 standard. We used its quality management system and the type B widened flexible scope to identify the required criteria based on microbiology and infection control standards and those of Afnor and Cofrac, and to validate the screening procedure. Accreditation was obtained for use of the Type B scope, for culture-based detection and identification (codes BA1 and BA5), for determination of the minimal inhibitory concentrations of glycopeptides (code BA6), and for the detection of resistance genes to glycopeptides by polymerase chain reaction (code BA8). The maturity of our quality management system contributed to validate the screening procedures following the required criteria of the NF EN ISO/IEC 17025 standard.

Colistin resistance in Parisian inpatient faecal Escherichia coli as the result of two distinct evolutionary pathways.

Beyond plasmid-encoded resistance (mcr genes) prevalence in strain collections, large epidemiological studies to estimate the human burden of colistin-resistant Escherichia coli gut carriage are lacking. To evaluate the prevalence of colistin-resistant E. coli carriage in inpatients and decipher the molecular support of resistance and the genetic background of the strains. During a 3 month period in 2017, we prospectively screened patients in six Parisian hospitals for rectal carriage of colistin-resistant E. coli using a selective medium, a biochemical confirmatory test and MIC determination. WGS of the resistant strains and their corresponding plasmids was performed. Among the 1217 screened patients, 153 colistin-resistant E. coli strains were isolated from 152 patients (12.5%). The mcr-1 gene was identified in only seven isolates (4.6%) on different plasmid scaffolds. The genetic background of these MCR-1 producers argued for an animal origin. Conversely, the remaining 146 colistin-resistant E. coli exhibited a phylogenetic distribution corresponding to human gut commensal/clinical population structure (B2 and D phylogroup predominance); 72.6% of those isolates harboured convergent mutations in the PmrA and PmrB proteins, constituting a two-component system shown to be associated with colistin resistance. We showed that the occurrence at a high rate of colistin resistance in human faecal E. coli is the result of two distinct evolutionary pathways, i.e. the occurrence of chromosomal mutations in an endogenous E. coli population and the rare acquisition of exogenous mcr-1-bearing strains probably of animal origin. The involved selective pressures need to be identified in order to develop preventative strategies.

2394. Different Clostridioides difficile Ribotypes Among Patients With Colonization, Initial Clinical Disease, and Recurrent Clinical Disease

Background C. difficile is the most common cause of hospital infections with a spectrum of presentation from asymptomatic carriage to severe recurrent diarrhea. Certain C. difficile ribotypes are associated with severe disease, but there are little data on ribotypes in asymptomatic carriers or severe recurrent disease. The aim of this study was to compare virulence potential of C.diff ribotypes with clinical disease severity.MethodsThis retrospective study included patients aged ≥18 years at NorthShore University HealthSystem (NUHS) from February 1, 2015 to May 30, 2017. Three groups of patients with positive PCR test for C. diff toxin gene were selected: (1) Asymptomatic patients positive for rectal carriage; (2) symptomatic outpatients with a single positive test (CDI); and (3) patients with recurrent CDI who underwent FMT. Clinical data were extracted from the Enterprise Database Warehouse. Isolates underwent fluorescent PCR ribotyping and were assigned to clades. Ribotypes with “high” (e.g., 027 and 078) and “low” (e.g., 106) virulence potential were defined as such. Virulence potential of cryptic ribotypes were considered “unknown.” We used Χ2 and independent samples median tests to compare categorical and continuous variables, respectively.Results129 C. diff isolates (asymptomatic, N = 66; CDI, N = 33; FMT, N = 30) were ribotyped with 60 types identified. Median age was higher in asymptomatic patients [80.5 (IQR 70.8–90) years] compared with both CDI and FMT [69 (58–81) and 69 (51–83.5) years, respectively, P = 0.004] Low virulence ribotypes were identified more frequently in asymptomatic carriers than those with CDI or FMT (22/66 vs. 8/33 vs. 1/30, respectively, P = 0.006). High virulence ribotypes were found in all groups, with highest frequency in the FMT group (23/30) vs. asymptomatic (25/67) or CDI (13/33), P = 0.001).ConclusionPatients with severe or recurrent CDI had ribotypes associated with high virulence potential. In addition, asymptomatic carriers were more likely to have ribotypes of C.diff historically associated with a low virulence potential. Molecular C.diff typing may have a role in evaluating asymptomatic C.diff colonization vs. clinical disease.Disclosures All authors: No reported disclosures.

1559. Hematopoietic Cell Transplantation with Post-transplant Cyclophosphamide: Impact of Donor Type on Pre-engraftment Blood-Stream Infections

BackgroundThe aim of the study was to estimate the cumulative incidence of pre-engraftment blood stream infections (PE-BSI), its predictive factors and the infection-related mortality (IRM) after hematopoietic cell transplantation (HCT) from any donor type, with post-transplant cyclophosphamide (PT-Cy).MethodsRetrospective cohort study on 235 adults who underwent peripheral blood HCT from every donor type with PT-Cy platform, from 2013 to 2017 at San Raffaele Scientific Institute. The Poisson regression was used to estimate the crude incidence rate (IR) of PE-BSI. The Fine-Gray competing risk model was applied to estimate the cumulative incidence function (CIF) of the first PE-BSI and its predictive factors and of IRM.ResultsPatients’ characteristics are reported in Table 1. During 5,316 person-days of follow-up (PDFU), 77 PE-BSI episodes occurred in 72 patients: IR = 1.45 per 100-PDFU [95% confidence interval (95% CI) 1.13–1.77]. The median time to PE-BSI was 13 days (IQR: 7–17) and the estimated CIF at 28 days was 32% (95% CI: 26–39%); no differences in CIF according to donor type [30% vs. 34% vs. 32% in match-related, match-unrelated and haploidentical donor, respectively; Gray’s test: P = 0.968]. Among the 87 isolated pathogens, 60% were Gram-positive bacteria (GPB), 39% Gram-negative bacteria (GNB) and 1% nontuberculous mycobacteria. CIFs of GNB and GPB PE-BSI by type of donor are shown in Figure 1. By multivariate analysis (Table 2), after adjustment for age, sex, year of HCT, donor type and disease phase at HCT, the CIF of any PE-BSI was higher in subjects with absolute neutrophils count ≤500 for ≥7 days before HCT [adjusted hazard ratio (AHR) = 2.90] and in multi-drug resistant (MDR) GNB rectal carriers before HCT [AHR = 2.68]. These covariates were confirmed as independent factors also for GNB PE-BSI. Overall, IRM at 30 days was 5% (95% CI: 2–8%) with no differences by donor type (Gray’s test: P = 0.106).ConclusionHCT with PT-Cy platform showed a 32% of cumulative incidence of PE-BSI at 28 days and donor type did not affect its occurrence, which was conversely increased by prolonged and severe neutropenia and MDR GNB rectal carriage before HCT. Haploidentical setting did not retain a higher IRM at 30 days than match-related and match-unrelated donors. Disclosures All authors: No reported disclosures.

Tolmetin sodium-loaded thermosensitive mucoadhesive liquid suppositories for rectal delivery; strategy to overcome oral delivery drawbacks

Tolmetin sodium (TS) is a nonsteroidal anti-inflammatory drug (NSAID) indicated for treatment of musculoskeletal issues. As other NSAID, TS displays a marked side effects on the gastro-intestinal (GI) tract after oral administration. Traditional solid suppositories can cause pain and discomfort for patients, may reach the end of the colon; consequently, the drug can undergo the first-pass effect. TS liquid suppository (TS-LS) was developed to enhance patient compliance and rectal mucosal safety in high-risk patients receiving highly NSAID therapy. This work was conducted to optimize and evaluate Poloxamer P407/P188-based thermoresponsive TS-LS by using mucoadhesive polymers such as methylcellulose (MC). TS-LS was prepared by cold method and characterized their in vitro physicochemical properties as gelation temperature (GT), gel strength, bioadhesive properties, and in vitro release. The safety of the prepared suppository on rectum, stomach, and liver was evaluated histologically. Pharmacokinetic analyses were performed to compare rectal TS-LS to orally Rhumtol® capsules. The results showed that the optimized TS-LS; composed of P407/P188/MC (21/9/0.5% w/w) displayed gelation at rectum temperature ∼32.90 °C, gel strength of 21.35 s and rectal retention force at the administration site of 24.25 × 102 dyne/cm2. Moreover, TS-LS did not cause any morphological damage to the rectal tissues. Pharmacokinetic parameters of optimized TS-LS formulation revealed 4.6 fold increase in bioavailability as compared to Rhumtol® capsules. Taken together, the results demonstrated that liquid suppository is a potential and physically safe rectal delivery carrier for improvement rectal bioavailability and in vivo safety of TS.

Whole genome sequencing of toxigenic Clostridium difficile in asymptomatic carriers: insights into possible role in transmission

Estimates of the prevalence of asymptomatically carried Clostridium difficile in elderly patients in long-term care range from 0% to 51%. Asymptomatic carriage is possibly a risk factor for the development of infection, and there is ongoing debate surrounding the role of asymptomatic carriage in transmission. To investigate the prevalence of asymptomatic carriage amongst patients residing in intermediate care (bedded) facilities (ICBFs), and to investigate whether asymptomatically carried C.difficile strains contribute to nosocomial C.difficile infection (CDI). Stools were collected from eligible asymptomatic patients in ICBFs, and a subset was also processed from symptomatic patients accessing primary or secondary care outside of ICBFs. All samples were cultured for C.difficile, and resulting colonies were processed through whole genome sequencing. In total, 151 asymptomatic patients were sampled, 22 of which were positive for C.difficile through stool culture, representing a carriage rate of 14.6%. Sequencing of these isolates, alongside 14 C.difficile polymerase chain reaction and culture-positive isolates from symptomatic individuals, revealed that all asymptomatic patients were carrying toxigenic C.difficile, and these strains were genetically similar to those from symptomatic patients. This small study of asymptomatic carriage revealed a rectal asymptomatic carriage rate of 14.6% in patients nursed in ICBFs, and a high level of genetic similarity of these strains to those recovered from symptomatic patients. As such, asymptomatic carriers may be important for the transmission of symptomatic CDI, although it is acknowledged that this study was small, and many other factors govern whether C.difficile is carried asymptomatically or causes symptoms.

Decline in AmpC β-lactamase-producing Escherichia coli in a Dutch teaching hospital (2013-2016).

ObjectiveThe objective of this study is to determine the prevalence of rectal carriage of plasmid- and chromosome-encoded AmpC β-lactamase-producing Escherichia coli and Klebsiella spp. in patients in a Dutch teaching hospital between 2013 and 2016.MethodsBetween 2013 and 2016, hospital-wide yearly prevalence surveys were performed to determine the prevalence of AmpC β-lactamase-producing E. coli and Klebsiella spp. rectal carriage. Rectal swabs were taken and cultured using an enrichment broth and selective agar plates. All E. coli and Klebsiella spp. isolates were screened for production of AmpC β-lactamase using phenotypic confirmation tests and for the presence of plasmid-encoded AmpC (pAmpC) genes. E. coli isolates were screened for chromosome-encoded AmpC (cAmpC) promoter/attenuator alterations.ResultsFifty (2.4%) of 2,126 evaluable patients were identified as rectal carrier of AmpC β-lactamase-producing E. coli. No carriage of AmpC β-lactamase producing Klebsiella spp. was found. Nineteen (0.9%) patients harboured isolates with pAmpC genes and 30 (1,4%) patients harboured isolates with cAmpC promoter/attenuator alterations associated with AmpC β-lactamase overproduction. For one isolate, no pAmpC genes or cAmpC promotor/attenuator alterations could be identified. During the study period, a statistically significant decline in the prevalence of rectal carriage with E. coli with cAmpC promotor/attenuator alterations was found (p = 0.012). The prevalence of pAmpC remained stable over the years.ConclusionsThe prevalence of rectal carriage of AmpC-producing E. coli and Klebsiella spp. in patients in Dutch hospitals is low and a declining trend was observed for E. coli with cAmpC promotor/attenuator alterations.

Carriage of antibiotic-resistant Gram-negative bacteria after discontinuation of selective decontamination of the digestive tract (SDD) or selective oropharyngeal decontamination (SOD)

BackgroundSelective decontamination of the digestive tract (SDD) and selective oropharyngeal decontamination (SOD) reduce colonization with antibiotic-resistant Gram-negative bacteria (ARGNB), incidence of nosocomial infections and improve survival in ICU patients. The effect on bacterial gut colonization might be caused by growth suppression by antibiotics during SDD/SOD. We investigated intestinal colonization with ARGNB after discharge from ICU and discontinuation of SDD or SOD.MethodsWe performed a prospective, observational follow-up study in regular hospital wards of three teaching hospitals in the Netherlands in patients discharged from the ICU, who were participating in a cluster randomized trial comparing SDD with SOD. We determined rectal carriage with ARGNB at ICU discharge (time (T) = 0) and 3, 6 and 10 days after discharge. The primary endpoint was time to first colonization with ARGNB that was not present at T = 0. Bacteria that are intrinsically resistant to antibiotics were not included in the primary analysis, but were included in post-hoc analysis.ResultsOf 1370 patients screened for inclusion, 996 patients had samples at T = 0 (507 after SDD and 489 after SOD). At ICU discharge, the prevalence of intestinal carriage with any ARGNB was 22/507 (4.3%) after SDD and 87/489 (17.8%) after SOD (p < 0.0001): 426 (SDD) and 409 (SOD) patients had at least one follow-up sample for analysis. The hazard rate for acquiring carriage of ARGNB after discontinuation of SDD, compared to SOD, in the ICU was 0.61 (95% CI 0.40–0.91, p = 0.02), and cumulative risks of acquisition of at least one ARGNB until day 10 were 13% (SDD) and 18% (SOD). At day 10 after ICU discharge, the prevalence of intestinal carriage with ARGNB was 11.3% (26/230 patients) after SDD and 12.5% (28/224 patients) after SOD (p = 0.7). In post-hoc analysis of all ARGNB, including intrinsically resistant bacteria, colonization at ICU discharge was lower after SDD (4.9 vs. 22.3%, p < 0.0001), but acquisition rates after ICU discharge were similar in both groups.ConclusionsIntestinal carriage at ICU discharge and the acquisition rate of ARGNB after ICU discharge are lower after SDD than after SOD. The prevalence of intestinal carriage with ARGNB at 10 days after ICU discharge was comparable in both groups, suggesting rapid clearance of ARGNB from the gut after ICU discharge.Trial registrationNetherlands Trial Registry, NTR3311. Registered on 28 february 2012.

Pathogen colonization of the gastrointestinal microbiome at intensive care unit admission and risk for subsequent death or infection.

Loss of colonization resistance within the gastrointestinal microbiome facilitates the expansion of pathogens and has been associated with death and infection in select populations. We tested whether gut microbiome features at the time of intensive care unit (ICU) admission predict death or infection. This was a prospective cohort study of medical ICU adults. Rectal surveillance swabs were performed at admission, selectively cultured for vancomycin-resistant Enterococcus (VRE), and assessed using 16S rRNA gene sequencing. Patients were followed for 30days for death or culture-proven bacterial infection. Of 301 patients, 123 (41%) developed culture-proven infections and 76 (25%) died. Fecal biodiversity (Shannon index) did not differ based on death or infection (p = 0.49). The presence of specific pathogens at ICU admission was associated with subsequent infection with the same organism for Escherichia coli, Pseudomonas spp., Klebsiella spp., and Clostridium difficile, and VRE at admission was associated with subsequent Enterococcus infection. In a multivariable model adjusting for severity of illness, VRE colonization and Enterococcus domination (≥ 30% 16S reads) were both associated with death or all-cause infection (aHR 1.46, 95% CI 1.06-2.00 and aHR 1.47, 95% CI 1.00-2.19, respectively); among patients without VRE colonization, Enterococcus domination was associated with excess risk of death or infection (aHR 2.13, 95% CI 1.06-4.29). Enterococcus status at ICU admission was associated with risk for death or all-cause infection, and rectal carriage of common ICU pathogens predicted specific infections. The gastrointestinal microbiome may have a role in risk stratification and early diagnosis of ICU infections.

Serial Clustering of Late-Onset Group B Streptococcal Infections in the Neonatal Unit: A Genomic Re-evaluation of Causality.

BackgroundInvasive Group B streptococcus (GBS) is a major cause of serious neonatal infection. Current strategies to reduce early-onset GBS disease have no impact on late-onset disease (LOD). Although GBS LOD is viewed as a sporadic event in the community, LOD arising within the neonatal intensive care unit (ICU) raises questions about mode of acquisition.MethodsFollowing a cluster of 4 GBS LOD cases, enhanced surveillance for all GBS LOD was undertaken over 2 years in the neonatal ICU supported by neonatal rectal screening. GBS isolates were serotyped and genome-sequenced.ResultsTwelve late -onset invasive GBS episodes were identified (incidence 0.6/1000 live births). Genomic analysis revealed that 11/12 GBS isolates (92%) were linked to at least one other LOD isolate. Isolates from the first cluster were serotype V, resistant to macrolides and lincosamides, and sequencing confirmed isolates were indistinguishable, or distinguishable by only one SNP difference, from each other. Rectal carriage was rare. Prospective surveillance identified three further clusters of LOD due to serotypes Ia (3 cases), Ib (2 cases), and III (2 cases), that would not have been identified without surveillance and genome sequencing, leading to a re-evaluation of interventions required to prevent GBS LOD.ConclusionAcquisition routes for LOD GBS in the neonatal ICU are poorly understood; cases may not necessarily be sporadic. Within this neonatal ICU, our data suggest that a single case of LOD GBS sepsis should be considered a potential nosocomial transmission event warranting prompt investigation, heightened infection prevention vigilance and action where required.

Listeria

Listeria

Antimicrobial-Resistant Klebsiella pneumoniae Carriage and Infection in Specialized Geriatric Care Wards Linked to Acquisition in the Referring Hospital.

Klebsiella pneumoniae is a leading cause of extended-spectrum β-lactamase (ESBL)-producing hospital-associated infections, for which elderly patients are at increased risk. We conducted a 1-year prospective cohort study, in which a third of patients admitted to 2 geriatric wards in a specialized hospital were recruited and screened for carriage of K. pneumoniae by microbiological culture. Clinical isolates were monitored via the hospital laboratory. Colonizing and clinical isolates were subjected to whole-genome sequencing and antimicrobial susceptibility testing. K. pneumoniae throat carriage prevalence was 4.1%, rectal carriage 10.8%, and ESBL carriage 1.7%, and the incidence of K. pneumoniae infection was 1.2%. The isolates were diverse, and most patients were colonized or infected with a unique phylogenetic lineage, with no evidence of transmission in the wards. ESBL strains carried blaCTX-M-15 and belonged to clones associated with hospital-acquired ESBL infections in other countries (sequence type [ST] 29, ST323, and ST340). One also carried the carbapenemase blaIMP-26. Genomic and epidemiological data provided evidence that ESBL strains were acquired in the referring hospital. Nanopore sequencing also identified strain-to-strain transmission of a blaCTX-M-15 FIBK/FIIK plasmid in the referring hospital. The data suggest the major source of K. pneumoniae was the patient's own gut microbiome, but ESBL strains were acquired in the referring hospital. This highlights the importance of the wider hospital network to understanding K. pneumoniae risk and infection prevention. Rectal screening for ESBL organisms on admission to geriatric wards could help inform patient management and infection control in such facilities.

Quantifying Hospital-Acquired Carriage of Extended-Spectrum Beta-Lactamase-Producing Enterobacteriaceae Among Patients in Dutch Hospitals.

BACKGROUND Extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) are emerging worldwide. Contact precautions are recommended for known ESBL-E carriers to control the spread of ESBL-E within hospitals. OBJECTIVE This study quantified the acquisition of ESBL-E rectal carriage among patients in Dutch hospitals, given the application of contact precautions. METHODS Data were used from 2 cluster-randomized studies on isolation strategies for ESBL-E: (1) the SoM study, performed in 14 Dutch hospitals from 2011 through 2014 and (2) the R-GNOSIS study, for which data were limited to those collected in a Dutch hospital in 2014. Perianal cultures were obtained, either during ward-based prevalence surveys (SoM), or at admission and twice weekly thereafter (R-GNOSIS). In both studies, contact precautions were applied to all known ESBL-E carriers. Estimates for acquisition of ESBL-E were based on the results of admission and discharge cultures from patients hospitalized for more than 2 days (both studies) and a Markov chain Monte Carlo (MCMC) model, applied to all patients hospitalized (R-GNOSIS). RESULTS The absolute risk of acquisition of ESBL-E rectal carriage ranged from 2.4% to 2.9% with an ESBL-E acquisition rate of 2.8 to 3.8 acquisitions per 1,000 patient days. In addition, 28% of acquisitions were attributable to patient-dependent transmission, and the per-admission reproduction number was 0.06. CONCLUSIONS The low ESBL-E acquisition rate in this study demonstrates that it is possible to control the nosocomial transmission of ESBL in a low-endemic, non-ICU setting where Escherichia coli is the most prevalent ESBL-E and standard and contact precautions are applied for known ESBL-E carriers. TRIAL REGISTRATION Nederlands Trialregister, NTR2799, http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2799; ISRCTN Registry, ISRCTN57648070, http://www.isrctn.com/ISRCTN57648070 Infect Control Hosp Epidemiol 2018;39:32-39.

A multi-centre prospective evaluation of the Check-Direct ESBL Screen for BD MAX as a rapid molecular screening method for extended-spectrum beta-lactamase-producing Enterobacteriaceae rectal carriage

A multiplex extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) quantitative polymerase chain reaction (qPCR), performed directly on rectal swabs, was compared with a culture-based protocol to study the discrepancies between the two methods, and identify existing challenges to apply this assay in routine clinical practice. The secondary objective was to assess the performance of the qPCR. In two Dutch teaching hospitals, 573 rectal swabs were collected prospectively. Culture with additional testing with the Check-MDR CT103XL (Check-Points) was compared with the Check-Direct ESBL Screen for BD MAX (Check-Points), which detects the presence of the ESBL gene families CTX-M1, CTX-M2, CTX-M9 and SHV2/5-ESBL. The culture-based protocol (with Brilliance agar) was considered as the gold standard to assess the performance of the qPCR. Of the 573 rectal swabs, 74 (12.9%) were culture-positive. Eighty-four (14.7%) were qPCR-positive. There were eight culture-positive/qPCR-negative discrepancies and 18 culture-negative/qPCR-positive discrepancies. Sensitivity and specificity of qPCR vs culture were 87.7% [95% confidence interval (CI) 79.7-95.7] and 96.3% (95% CI 94.6-98.0), respectively. The Check-Direct ESBL Screen for the BD MAX is an easy-to-perform, quick molecular diagnostic test with the potential to significantly speed up screening for rectal ESBL-E carriage. Discrepancies were observed between the culture-based protocol and the qPCR in 4.5% of tested samples. Existing challenges for implementing qPCR are its limited sensitivity, the need for thorough knowledge of the local ESBL-E genes, and interpretation of culture-negative but qPCR-positive samples. It is believed that the limited sensitivity of qPCR could be optimized by including blaTEM as a molecular target, and improving the limit of detection.

A hospital-based matched case-control study to identify risk factors for clinical infection with OXA-48-producing Klebsiella pneumoniae in rectal carriers.

Asymptomatic colonisation of the gastrointestinal tract by carbapenemase-producing Enterobacteriaceae is an important reservoir for transmission, which may precede infection. This retrospective observational case-control study was designed to identify risk factors for developing clinical infection with OXA-48-producing Klebsiella pneumoniae in rectal carriers during hospitalisation. Case patients (n = 76) had carbapenemase-producing K. pneumoniae (CPKP) infection and positive rectal culture for CPKP. Control patients (n = 174) were those with rectal colonisation with CPKP but without CPKP infection. Multivariate analysis identified the presence of a central venous catheter (OR 4·38; 95% CI 2·27-8·42; P = 0·008), the number of transfers between hospital units (OR 1·27; 95% CI (1·06-1·52); P < 0·001) and time at risk (OR 1·02 95% CI 1·01-1·03; P = 0·01) as independent risk factors for CPKP infection in rectal carriers. Awareness of these risk factors may help to identify patients at higher risk of developing CPKP infection.

The prevalence of rectal carriage of Klebsiella pneumoniae amongst diabetic patients and their clinical relevance in Taiwan: A five-year prospective study.

Pyogenic liver abscess (PLA) and bacteremia caused by Klebsiella pneumoniae is a common complication among patients with diabetes mellitus (DM). The aim of this study is to investigate the prevalence of rectal carriage and serotype distribution of K. pneumoniae amongst DM patients and their clinical relevance. We prospectively collected rectal swabs for K. pneumoniae culture in asymptomatic DM patients from March 2008 to June 2009. Seven capsular serotypes that were commonly associated with PLA were determined by capsular polysaccharide synthesis (cps) genotyping. Microbiologically confirmed bacterial infections were evaluated 1 and 5 years after initial enrolment of the patients. A total of 100 male and 62 female patients (mean age, 56.6 years) were enrolled. Of these, 77 (47.5%) had rectal K. pneumoniae colonization. Colonizers were older than non-colonizers (p=0.03). Sex, fasting blood glucose, and initial HbA1C were not statistically different (p=0.26, 0.18, and 0.31, respectively). Among the 65 available isolates, 22 (33.8%) belonged to the seven main serotypes. During the 5-year's follow-up, 21 patients developed microbiologically documented bacterial infections but none of them developed PLA and bacteremia. Risk factors for bacterial infection within 5 years included initial glycosylated hemoglobin (HbA1C)>10% or first-year average HbA1C>10%. Although nearly half of asymptomatic DM patients had rectal carriage of K. pneumoniae and one-third of them colonized by isolates belonging to the seven serotypes related to PLA, none of them subsequently developed PLA and colonized patients did not have higher risk of microbiologically confirmed bacterial infections.

Evaluation of self-collected rectal swabs for the detection of bacteria responsible for sexually transmitted infections in a cohort of HIV-1-infected patients.

Purpose. The standard approach to screening sexually transmitted infections (STIs) has often been restricted to urogenital specimens. Most current guidelines, however, also recommend testing extra-genital sites, including rectal locations, because asymptomatic rectal carriage of pathogens has often been reported. The aim of our study was to evaluate self-collected rectal swabs to screen bacterial STIs in HIV-infected patients in Marseille, France.Methodology. Between January 2014 and December 2015, 118 HIV-infected patients (93 males and 25 females) agreed to self-sample anal swabs for detection of bacterial STI. Detection of Neisseria gonorrhoeae, Chlamydia trachomatis, Treponema pallidum, Mycoplasma genitalium and Haemophilus ducreyi was performed using in-house qPCR assay.Results/Key findings. Bacterial STIs were found in 8 % (9/118) of the patients. C. trachomatis was the most commonly detected bacterium (4.2 %) followed by N. gonorrhoeae (2.5 %), M. genitalium (1.7 %) and T. pallidum (0.8 %). All the positive patients were males. The rectal carriage of pathogenic bacteria was fortuitously discovered for seven men (78 %) who did not present rectal signs of STIs and was suspected for two men who presented proctitis (22 %).Conclusion. In conclusion, testing extra-genital sites is crucial for the diagnosis of STIs in men and women presenting or not concomitant urogenital infections in order to detect asymptomatic carriage with the aim of controlling and preventing transmission to their sexual partners.

Risk factors for acquisition of CTX-M genes in pilgrims during Hajj 2013 and 2014.

Mass gatherings, especially the Hajj pilgrimage, provide favourable conditions for bacterial transmission among participants, which might contribute to the international spread of ESBL-producing Enterobacteriaceae (ESBL-E). We conducted an analysis aimed at investigating risk factors for CTX-M gene (blaCTX-M) rectal carriage in 2013 and 2014 Hajj pilgrims. A total of 218 pilgrims provided paired pre- and post-Hajj rectal samples (2013, 129 pilgrims; 2014, 89 pilgrims). CTX-M genes in rectal samples were identified by PCR and confirmed by sequencing. Pilgrims' characteristics, including possible factors relating to ESBL acquisition, were collected and analysed using XLSTAT version 2016.05.34687 (Addinsoft). For the univariate analysis, the frequencies of nominal data were compared using Pearson's χ2 test and Fisher's exact test, and the means of quantitative data were compared using Student's t-test. A difference was considered significant when P < 0.05. For multivariate analysis, a logistic regression was carried out, considering all the significant data in univariate analysis. The acquisition rates of CTX-M genes among pilgrims during the 2013 and 2014 Hajj were similar, at 31.0% and 34.83%, respectively. Being of Moroccan origin, having chronic conditions, shortness of breath or diarrhoea, and using β-lactams were associated with higher CTX-M gene acquisition, while being of Algerian origin and using macrolides were associated with lower CTX-M acquisition in univariate analysis. Shortness of breath and diarrhoea remained associated with increased CTX-M gene acquisition and consumption of macrolides with lower CTX-M gene acquisition in multivariate analysis. The possible gut colonization by CTX-M-type ESBL bacteria should be taken into account when prescribing empirical antibiotic treatments for infections that occur in returning Hajj pilgrims.