Rectal Swab Specimens Research Articles

Rectal swab sampling followed by an enrichment culture-based real-time PCR assay to detect Salmonella enterocolitis in children

Although routine bacterial culture is the traditional reference standard method for the detection of Salmonella infection in children with diarrhoea, it is a time-consuming procedure that usually only gives results after 3–4 days. Some molecular detection methods can improve the turn-around time to within 24 h, but these methods are not applied directly from stool or rectal swab specimens as routine diagnostic methods for the detection of gastrointestinal pathogens. In this study, we tested the feasibility of a bacterial enrichment culture-based real-time PCR assay method for detecting and screening for diarrhoea in children caused by Salmonella. Our results showed that the minimum real-time PCR assay time required to detect enriched bacterial culture from a swab was 3 h. In all children with suspected Salmonella diarrhoea, the enrichment culture-based real-time PCR achieved 85.4% sensitivity and 98.1% specificity, as compared with the 53.7% sensitivity and 100% specificity of detection with the routine bacterial culture method. We suggest that rectal swab sampling followed by enrichment culture-based real-time PCR is suitable as a rapid method for detecting and screening for Salmonella in paediatric patients.

P3-S1.15 The molecular diagnosis of rectal GC and CT infections using the FTA elute card for specimen collection and the real-time multiplex PCR for detection

Background To evaluate the potential use of the Whatman Indicating FTA Elute Micro Card for collection, transport, and storage of rectal swab specimens for subsequent detection of STD pathogens in MSM using a TaqMan-based real-time multiplex PCR. Methods Two rectal swabs were obtained by the physician from each participant in a study to determine carriage of STD pathogens among MSM. One of the swabs was placed into a tube containing 1 ml of Genelock transport medium and while the other swab was firmly pressed onto an FTA Card with three side to side motions held at approximately 60° angle each time. Genomic DNA was eluted from three discs (3 mm diameter) punched out of each card after storage at room temperature for up to 6 months and tested by a real-time multiplex PCR assay which simultaneously detects lymphogranuloma venereum (LGV), non- LGV, Chlamydia trachomatis (CT), and Neisseria gonorrhoeae (GC), and human DNA control. For comparison, an aliquot of sample from genelock tube was extracted using the Qiagen DNA mini kit and tested with same real-time multiplex PCR assay. Results Using purified DNA obtained from the Genelock specimens, the real-time multiplex PCR assay detected nine GC and 17 non-LGV CT; while 7 GC and 15 non-LGV CT were detected in DNA samples eluted from the FTA Cards and used directly for PCR. There were three GC and non-LGV co-infections and no LGV was detected using both specimen collection methods. A substantial number of specimens were found to be PCR inhibitory either collected in Genelock (18.3%) or on FTA Cards (15.4%). Conclusions The FTA Elute Micro Card allows stable storage and convenient transport of rectal swab specimens at room temperature. DNA can be eluted from the card with simple processes instead of numerous purification procedures for downstream real-time PCR amplification and aetiology detection. This preliminary evaluation shows the potential use of FTA Card for rectal specimen collection and PCR testing, and may also provide a cost-saving alternative to expensive international shipping of specimens on dry ice from remote study sites.

Extended-Spectrum B-Lactamase Genes of Escherichia coli in Chicken Meat and Humans, the Netherlands

We determined the prevalence and characteristics of extended-spectrum β-lactamase (ESBL) genes of Enterobacteriaceae in retail chicken meat and humans in the Netherlands. Raw meat samples were obtained, and simultaneous cross-sectional surveys of fecal carriage were performed in 4 hospitals in the same area. Human blood cultures from these hospitals that contained ESBL genes were included. A high prevalence of ESBL genes was found in chicken meat (79.8%). Genetic analysis showed that the predominant ESBL genes in chicken meat and human rectal swab specimens were identical. These genes were also frequently found in human blood culture isolates. Typing results of Escherichia coli strains showed a high degree of similarity with strains from meat and humans. These findings suggest that the abundant presence of ESBL genes in the food chain may have a profound effect on future treatment options for a wide range of infections caused by gram-negative bacteria.

Concurrent Influenza and Shigellosis Outbreaks, Papua New Guinea, 2009

Concurrent Influenza and Shigellosis Outbreaks, Papua New Guinea, 2009

Evaluation of PCR-based screening for vancomycin-resistant enterococci compared with a chromogenic agar-based culture method

Rapid detection of vancomycin-resistant enterococci (VRE) infection is very important for control and prevention of nosocomial spread of these bacteria. A multiplex PCR method for rapid screening of VRE has recently been developed. We performed a prospective study of VRE screening tests to compare the performance of PCR to that of a chromogenic agar-based culture method. From January to December 2009, a total of 8815 rectal swab specimens were tested simultaneously for VRE by VRE selective culture and by PCR. The specimens were inoculated onto ChromID VRE agar containing 8 µg vancomycin ml⁻¹ and examined after 24 and 48 h of incubation. Identification and antibiotic susceptibility tests were performed using the automated VITEK-2 system and a supplementary E-test and disk diffusion test. Detection of the vanA and vanB genes was performed with the Seeplex VRE detection kit. Specimens were inoculated in enterococcosel broth for 16-24 h before PCR for enrichment of VRE. VRE were isolated from 741 of the 8815 specimens by chromogenic agar-based culture (8.4 %). vanA and vanB genotypes were detected in 758 (8.6 %) and 3 (0.03 %) specimens, respectively, by multiplex PCR. Sensitivity, specificity, positive predictive value and negative predictive value of PCR for detection of VRE were 98.2 %, 99.6 %, 95.7 %, and 99.8 %. No VRE were isolated from vanB-positive specimens. The overall performance of PCR is comparable to that of a chromogenic agar-based culture method for screening of VRE, so PCR could be an alternative or supportive method for effective control of nosocomial VRE infection.

Utility of Urine, Vaginal, Cervical, and Rectal Specimens for Detection of Mycoplasma genitalium in Women

This study assessed the utility of urine, vaginal, cervical, and rectal specimens for the detection of Mycoplasma genitalium in women by using our laboratory-developed PCR assay. The relative sensitivity was 85.7% for the vaginal swab specimen, 74.3% for the endocervical swab specimen, 61.4% for the urine specimen, and 24.3% for the rectal swab specimen.

Respuesta completa al tratamiento con doxiciclina en pacientes con infección por VIH-1 con proctitis por linfogranuloma venéreo

We present a series of 15 cases with lymphogranuloma venereum (LGV) with the aim of evaluating the response to a 21-day oral course of doxycycline (100mg twice daily). It is an observational study where we describe a series of cases with LGV diagnosed in the Hospital Germans Trias i Pujol's HIV Unit between March 2008 and April 2009. All our patients were HIV infected men who had sex with men with proctitis in 80% of the cases. In all of them Chlamydia trachomatis was determined by PCR on rectal swab specimens, with a negative result after 21 days of treatment with doxycycline. Serovar L2 was confirmed in all the specimens with the reverse hybridization technique. A high index of clinical suspicion is the mainstay to the early diagnosis of LGV since the clinical presentation remains unspecific. The treatment with doxycycline eradicates C. trachomatis in HIV patients with LGV.

Prevalence and Antimicrobial Susceptibility ofCampylobacter coliIsolates from Swine

Swine is a common source of Campylobacter coli human gastroenteritis, for the treatment of which erythromycin and fluoroquinolones are recommended. The prevalence of antimicrobial-resistant C. coli differs significantly depending on countries. We investigated the prevalence of C. coli in swine from a farm in Buan-gun, Korea in 2010, and determined antimicrobial susceptibility of the isolates. Rectal swab specimens were used to inoculate Campylobacter Preston media and incubated microaerophilically at 42℃ for 48 h. The species were identified by phenotypic tests and by detecting hipO and glyA genes. PCR was used to detect mutations of A2074C in 23S rRNA gene, and quinolone resistancedetermining region (QRDR) of gyrA, which are associated with high level resistance to erythromycin, and with ciprofloxacin, respectively. Antimicrobial susceptibility was determined by the disk diffusion and agar dilution tests. Of the 100 specimens, 55 (55%) yielded C. coli, and 23 of them (41.8%) had A2074G mutation. A2074G mutated isolates showed the lowest MIC90 of imipenem, while those of ampicillin and clindamycin were relatively low. The majority of both A2074G mutation-positive and -negative isolate were susceptible to ampicillin, cefotaxime, and chloramphenicol. All isolates were resistant to ciprofloxacin, and had mutation in QRDR of gyrA. In conclusion, C. coli was detected in 55% of swine, and A2074G mutation was detected in 41.8% of the isolates. All isolates had gyrA mutation-mediated ciprofloxacin resistance.

Surveillance of shigellosis by real-time PCR suggests underestimation of shigellosis prevalence by culture-based methods in a population of rural China

Shigellosis is a leading public health issue in China, especially in Children under 5 years of age. The disease burden of shigellosis is usually underestimated by conventional culture. In this study, real-time PCR was applied to detect Shigella infection in parallel with routine culture, to investigate the true burden of disease caused by Shigella spp. Rectal swab specimens of 39 Shigella culture positive and 298 Shigella culture negative patients from a population-based surveillance study were selected randomly. Real-time PCR targeting the invasion plasmid antigen H gene sequence (ipaH) was used to detect DNA sequences characteristic for Shigella spp. ipaH were detected in 174 of 298 (58%) randomly selected Shigella culture negative specimens and in 38 of 39 (97%) Shigella culture positive specimens (p<0.001). Among 10 variables, culture results was the strongest predictive factor (OR=15.5; 95% CI: 2.0-119.0), followed by a clinical presentation of diarrhea with fever (OR=2.8; 95% CI: 1.2-6.2), epidemic season (OR=2.4; 95% CI: 1.4-4.3), and female gender (OR=1.8; 95% CI: 1.1-3.0). The high detection rate of ipaH in culture negative specimens through use of real-time PCR suggests that earlier estimates of shigellosis burden measured by conventional culture may have underestimated the true disease burden.

Multicenter Evaluation of the BD Max GBS Assay for Detection of Group B Streptococci in Prenatal Vaginal and Rectal Screening Swab Specimens from Pregnant Women

A new integrated extraction and real-time PCR-based system for the detection of group B streptococci in antepartum screening samples enriched in Lim broth was compared to the CDC-recommended culture method. The BD Max GBS assay exhibited acceptable sensitivity (95%) and specificity (96.7%) compared to those of the culture method in this multisite evaluation.

Evaluation of BBL CHROMagar VanRE for Detection of Vancomycin-Resistant Enterococci in Rectal Swab Specimens

A study was performed on 517 surveillance rectal swabs to evaluate a selective and differential chromogenic medium, the BBL CHROMagar VanRE (CVRE), which enables recovery and identification of VanA- and VanB-containing Enterococcus faecium (ENFM) and Enterococcus faecalis (ENFS) isolates. Compared to BBL Enterococcosel agar, a bile-esculin-azide-vancomycin (BEAV) agar, the initial overall sensitivity, specificity, and positive and negative predictive values of CVRE for the detection of vancomycin-resistant ENFM and ENFS were 99.1% and 94.8% and 84.2% and 99.7%, respectively. Among our patient population, more vancomycin-resistant enterococci (VRE) were recovered with CVRE than BEAV.

Prospective, Multicenter Evaluation of the BD GeneOhm VanR Assay for Direct, Rapid Detection of Vancomycin-Resistant Enterococcus Species in Perianal and Rectal Specimens

The BD GeneOhm VanR assay (BD Diagnostics, San Diego, CA), a qualitative test for the rapid detection of vancomycin-resistant enterococci (VRE) from rectal and/or perianal swabs, combines integrated nucleic acid extraction and automated polymerase chain reaction for the detection of vanA and/or vanB gene sequences. We studied 1,027 perianal and rectal swab specimens from 3 geographically distinct US sites (prevalence rates, 13.1%-25.8%). Direct swab specimens were tested by the assay and compared with direct culture. The sensitivity, specificity, and positive and negative predictive values of the assay were 93.2%, 81.9%, 54.4%, and 98.1%, respectively. The specificity was limited largely due to false-positives in the vanB portion of the assay. Specificity with perianal swabs was significantly greater than with rectal swabs, 87.1% vs 74.7%, respectively (P < .0001). When used only to detect resistance conferred by vanA, the assay was 88.3% (158/179) sensitive and 95.8% (802/837) specific, with positive and negative predictive values of 81.9% and 97.4%, respectively. The assay is a simple, rapid, and acceptable method for screening for VRE in a variety of populations in which vanA is the predominant genotype. Samples positive for the vanB genotype should be confirmed by culture owing to the apparent high number of false-positive results.

Rapid detection of vancomycin-resistant enterococci from rectal swabs by the Cepheid Xpert vanA/ vanB assay

The detection of vancomycin-resistant enterococci using a novel commercial multiplex real-time polymerase chain reaction assay (Xpert™ vanA/ vanB, Cepheid, Sunnyvale, CA) was evaluated on 804 rectal swab specimens. Compared to enriched culture, sensitivity and negative predictive value of this method were 100%. Many false-positive results were recovered (sensitivity, 85.4%; positive predictive value, 8.7%), especially for the vanB gene.

Lymphogranuloma venereum proctitis masquerading as inflammatory bowel disease in 12 homosexual men

Lymphogranuloma venereum (LGV) is a recognized cause of proctitis. Symptoms, endoscopy and histology findings are similar in IBD and LGV proctitis. To characterize the clinical, endoscopic and histological features seen in men diagnosed initially with IBD and subsequently with LGV proctitis, and to attempt isolation of Chlamydia trachomatis DNA from the stored rectal biopsy specimens of these patients using real-time PCR. Clinical data were collated from confirmed or suspected cases of LGV proctitis where endoscopy and biopsy had been performed as part of the investigation of clinical symptoms. LGV was confirmed by the detection of LGV-specific DNA from rectal swab specimens, with supportive evidence from Chlamydial serology. Stored histological specimens from rectal biopsies were analysed retrospectively for LGV-specific DNA with molecular techniques. Rectal biopsies had been obtained from twelve cases of LGV proctitis. Mucosal ulcers, cryptitis, crypt abscesses and granulomas were common histological findings. Extraction of LGV-specific DNA from rectal biopsy specimens enabled confirmation of three suspected cases. During the recent LGV proctitis epidemic among UK men who have sex with men, it has become apparent that this infection may closely resemble IBD. Gastroenterologists should remain alert to LGV as a cause of proctitis in this group.

Intervention study of the association of antibiotic utilization measures with control of extended-spectrum β-lactamase (ESBL)-producing bacteria

We investigated the effects of replacing third-/fourth-generation cephalosporins with piperacillin–tazobactam on the rate of acquisition of extended spectrum β-lactamase-producing Klebsiella pneumoniae and Escherichia coli by patients hospitalized in a Department of Respiratory Medicine. This 9-month, prospective, non-controlled, intervention study comprised two phases: a 3-month pre-intervention phase (Phase I) and a 6-month intervention phase (Phase II), during which the use of third-/forth-generation cephalosporins was restricted and replaced by piperacillin–tazobactam. Rectal swabs were obtained within 24 h after admission (baseline screening), weekly, and 48 h before discharge during Phase I and the last 3 months of Phase II (Phase IIb). Swabs were tested for E. coli and K. pneumoniae, and extended spectrum β-lactamase production was detected with the double disc test. Use of third/fourth-generation cephalosporins decreased by 63.0% and 100%, respectively; while the use of piperacillin–tazobactam increased by 28-fold. The rate of acquisition of extended spectrum β-lactamase-producing E. coli and K. pneumoniae together in rectal swab specimens decreased in Phase IIb as compared with Phase I (19.5% vs 29.5%). Few rectal swab specimens were positive for extended spectrum β-lactamases-producing K. pneumoniae, and no substantial decrease in the rate of its acquisition was observed.

PWE-039 Lymphogranuloma venereum proctitis masquerading as inflammatory bowel disease in 12 homosexual men

<h3>Introduction</h3> Lymphogranuloma venereum (LGV) is a recognised cause of proctitis which can be difficult to distinguish clinically and histologically from inflammatory bowel disease (IBD). The condition was first described in 2004, following an outbreak in The Netherlands. Lymphogranuloma venereum (LGV) proctitis is caused by L1, L2 and L3 serovars of CT and has evaded detection in recent decades in developed countries. <h3>Aim</h3> We describe a case series of LGV proctitis seen among HIV-positive men who have sex with men (MSM) who underwent endoscopy and biopsy and were diagnosed provisionally with IBD. <h3>Methods</h3> A retrospective study was performed in an inner London hospital. Clinical data were collated from confirmed or suspected cases of LGV proctitis where endoscopy and biopsy had been performed as part of the investigation of clinical symptoms. LGV was confirmed by the detection of LGV-specific DNA from rectal swab specimens, with supportive evidence from Chlamydia serology. Stored histological specimens from rectal biopsies were analysed retrospectively for LGV-specific DNA with the use of molecular techniques. <h3>Results</h3> All 12 cases were in HIV positive homosexual men, median age 41.5 years (range 27–55). In all twelve cases of LGV proctitis rectal biopsies had been obtained. All patients were symptomatic at the time of endoscopy and endoscopic features of proctitis were present in 10 of 12 cases. Mucosal ulceration, cryptitis, crypt abscesses and granulomas were common histological findings but crypt distortion, where seen, was usually mild: in most cases these findings were attributed initially to IBD. All cases were reviewed in gastroenterology or colorectal surgical clinics, where provisional diagnosis of IBD or non-specific proctitis were made. Eight patients were commenced on courses of metronidazole or 5-aminosalicylates. Two patients were given courses of prednisolone. Extraction of LGV-specific DNA from rectal biopsy specimens enabled confirmation of three cases of suspected LGV. <h3>Conclusion</h3> During the recent epidemic of LGV proctitis among UK MSM, it has become apparent that the clinical, endoscopic and histological features of the infection may closely resemble IBD and this may obscure the diagnosis. Relevant clinicians and pathologists should be alerted to the current epidemiology and clinical features of LGV in the UK.

Nucleic Acid Amplification Tests for Diagnosis of Neisseria gonorrhoeae and Chlamydia trachomatis Rectal Infections

It is uncertain which methods for the diagnosis of rectal gonococcal and chlamydial infection are optimal. This study evaluated the performance of culture and nucleic acid amplification tests (NAATs) for rectal chlamydial and gonococcal diagnosis. From July 2003 until February 2007, 441 rectal test sets were collected from individuals attending a sexually transmitted disease clinic and three HIV clinics who gave a history of anal intercourse or were women at high risk for Neisseria gonorrhoeae or Chlamydia trachomatis infections. Rectal swab specimens were tested using culture and commercial NAATs employing transcription-mediated amplification (TMA), strand displacement amplification (SDA), and PCR amplification. Test performance was evaluated using a rotating standard by which patients were classified as infected if either two or three comparator tests were positive. Test sensitivities for the detection of N. gonorrhoeae ranged from 66.7% to 71.9% for culture to 100% for TMA. Specificities were 99.7% to 100% for culture and greater than 95.5% for all three NAATs. Test sensitivities for C. trachomatis ranged from 36.1% to 45.7% for culture and among NAATS from 91.4% to 95.8% for PCR to 100% for TMA. Specificities of the NAATs ranged from 95.6% to 98.5% (two-of-three standard) and from 88.8% to 91.8% (three-of-three standard). Over 60% and 80% of gonococcal and chlamydial infections, respectively, among men who have sex with men and over 20% of chlamydial infections in women would have been missed if the rectal site had not been tested. Currently available NAATs are more sensitive for the detection of chlamydial and gonococcal infection at the rectal site than is culture.

Direct Ertapenem Disk Screening Method for Identification of KPC-Producing Klebsiella pneumoniae and Escherichia coli in Surveillance Swab Specimens

Klebsiella pneumoniae carbapenemase (KPC) production in Gram-negative bacilli is an increasing problem worldwide. Rectal swab surveillance is recommended as a component of infection prevention programs, yet few screening methods are published. We compared detection of KPC-producing Klebsiella pneumoniae and Escherichia coli in surveillance specimens by 2 methods: (i) inoculation of swabs in tryptic soy broth containing 2 microg/ml imipenem followed by plating to MacConkey agar (MAC) (method 1) and (ii) streaking swabs on MAC onto which a 10-microg ertapenem disk was then placed (method 2). Simulated rectal swab specimens of challenge isolates from a collection of well-characterized K. pneumoniae and E. coli strains and salvage rectal swab specimens collected from patients at 4 different health care facilities over a 7-month period were tested. The gold-standard comparator was bla(KPC) PCR testing of isolates. Method 1 detected 4/9 (44%) KPC-positive challenge isolates. By method 2, 9/9 KPC-positive challenge isolates exhibited zones of inhibition of < or = 27 mm; all KPC-negative isolates exhibited zones of inhibition greater than 27 mm. The sensitivity and specificity of method 1 for detection of KPC-positive K. pneumoniae and E. coli in 149 rectal swab specimens were 65.6% (95% confidence interval [CI], 46.8% to 80.8%) and 49.6% (95% CI, 40.3% to 58.9%), respectively. With method 2, a zone diameter of < or = 27 mm had a sensitivity of 97.0% (95% CI, 82.5% to 99.8%) and specificity of 90.5% (95% CI, 83.3% to 94.9%) for detection of KPC in rectal swab specimens. Direct ertapenem disk testing is simpler, more sensitive, and more specific than selective broth enrichment with imipenem for detection of KPC-producing K. pneumoniae and E. coli in surveillance specimens.

An investigation of methicillin-resistant Staphylococcus aureus colonization in people and pets in the same household with an infected person or infected pet

To investigate the prevalence of concurrent methicillin-resistant Staphylococcus aureus (MRSA) colonization in people and pets in the same household with a person or pet with an MRSA infection and to compare MRSA isolates by use of molecular techniques. 2 cross-sectional evaluations conducted concurrently. 24 dogs, 10 cats, and 56 humans in part 1 and 21 dogs, 4 cats, and 16 humans in part 2 of the study. In both parts of the study, nasal swab specimens were collected from humans and nasal and rectal swab specimens were collected from household pets. Selective culture for MRSA was performed, and isolates were typed via pulsed-field gel electrophoresis (PFGE) and spa typing. Households were defined as positive when MRSA was isolated from at least 1 person (part 1) or 1 pet (part 2). In part 1, 6 of 22 (27.3%) households were identified with MRSA colonization in a person. In these households, 10 of 56 (17.9%) humans, 2 of 24 (8.3%) dogs, and 1 of 10 (10%) cats were colonized with MRSA. In part 2, only 1 of 8 households was identified with MRSA colonization in a pet. Most MRSA isolates obtained from humans and pets in the same household were indistinguishable by use of PFGE. The high prevalence of concurrent MRSA colonization as well as identification of indistinguishable strains in humans and pet dogs and cats in the same household suggested that interspecies transmission of MRSA is possible. Longitudinal studies are required to identify factors associated with interspecies transmission.

Prospective Evaluation of Colonization with Extended-Spectrum β-Lactamase (ESBL)–Producing Enterobacteriaceae Among Patients at Hospital Admission and of Subsequent Colonization with ESBL-Producing Enterobacteriaceae Among Patients During Hospitalization

To determine the rates of and risk factors for carriage and acquisition of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae during hospitalization. Cohort study. Shaare Zedek Medical Center, a 550-bed teaching hospital. During a 5-month period (February 1-June 30, 2004), 167 (8%) of 1,985 newly admitted general medical patients were enrolled in our study. Nasal, oropharyngeal, and rectal swab specimens were obtained at admission and every 2-3 days until hospital discharge or death. Enterobacteriaceae isolates were tested for ESBL, and Staphylococcus aureus isolates were tested for methicillin resistance. Of the 167 patients enrolled in our study, 15 (9%) were identified as nasal carriers of methicillin-resistant S. aureus (MRSA) at admission, and 13 (8%) were rectal carriers of ESBL-producing Enterobacteriaceae at admission. Univariate risk factors for rectal carriage of ESBL-producing Enterobacteriaceae included female sex (odds ratio [OR], 11 [95% confidence interval {CI}, 1.4-238]; P < .05), nursing home residence (OR, 6.9 [95% CI, 1.8-27]; P < .01), recent antibiotic treatment (OR, 9.8 [95% CI, 1.7-74]; P < .05), and concomitant nasal carriage of MRSA and/or ESBL-producing Enterobacteriaceae (OR, 5.8 [95% CI, 1.2-26]; P < .01). Multivariate risk factors were female sex and recent antibiotic treatment. During hospitalization, 35 (21%) of 167 patients had acquired rectal carriage of ESBL-producing Enterobacteriaceae (P = .002, for trend analysis). Of the 12 patients who were still in the hospital 2 weeks after admission, 4 (33%) were carriers of ESBL-producing Enterobacteriaceae. Univariate risk factors for acquisition included an age of older than 65 years (P < .005), nursing home residence (OR 2.6, [95% CI, 0.98-2.6]), impaired cognition (OR, 4.8 [95% CI, 1.9-12]), recent antibiotic treatment (OR, 2.7 [95% CI, 0.9-8.3]), respiratory assistance (OR, 4.2 [95% CI, 1.2-14]), and prolonged hospitalization. Multivariate risk factors were an age of older than 65 years and broad-spectrum antibiotic therapy. Rectal carriage of ESBL-producing Enterobacteriaceae occurred in 13 (8%) of 167 patients at admission to the medical departments of our hospital and in 4 (33%) of 12 patients still remaining in our hospital after 2 weeks.