Perianal Swabs Research Articles

First documentation of a clinical multidrug-resistant Enterobacter chuandaensis ST2493 isolate co-harboring blaNDM-1 and two blaKPC-2 bearing plasmids.

The increasing prevalence of carbapenem-resistant Enterobacter cloacae complex (CREC) poses great challenges to infection treatment in the clinical setting. In this study, we reported the emergence of carbapenemase in a rare species, Enterobacter chuandaensis, belonging to the Enterobacter cloacae complex (ECC). We elucidated the genetic characteristics of carbapenem-resistant isolate FAHZZU5885, co-harboring blaNDM-1 and blaKPC-2. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and average nucleotide identity (ANI) analysis were used to identify E. chuandaensis. S1 nuclease pulsed-field gel electrophoresis (S1-PFGE) and Southern blotting were used to clarify the number and size of the plasmids in FAHZZU5885. Antimicrobial phenotypes were identified by antimicrobial susceptibility testing (AST), and the characteristics of the strain were examined with whole-genome sequencing (WGS). The conjugation experiment and stability assay were conducted to verify the transferability and stability of the plasmid carrying carbapenemase-encoding genes. E. chuandaensis FAHZZU5885 was isolated from a perianal swab of a patient admitted to the ICU. This strain simultaneously carried blaNDM-1 and two blaKPC-2 genes. FAHZZU5885 was resistant to most of the tested antibiotics except for amikacin, tigecycline, and colistin. Two blaKPC-2 were located separately on two different plasmids, the ~ 120kb IncFIA-IncFII plasmid and the ~ 80kb IncR plasmid. Both plasmids shared the conserved sequence klcA-korC-ISkpn6-blaKPC-2-ISkpn27-tnpR-tnpA. The blaNDM-1-bearing plasmid had the potential to transfer and can remain stable after successive passages. In addition, the blaNDM-1 was carried on a ~ 80kb IncFII plasmid with the conserved sequence ISAba125-blaNDM-1-ble-trpF-dsbD-cutA-groS-groL. In summary, this study marks the first report of the multidrug-resistant E. chuandaensis strain FAHZZU5885 harboring two blaKPC-2-bearing plasmids, indicating the potential for the further dissemination of carbapenemase-encoding genes in novel species. The findings contribute to enhancing our understanding of CREC strains, emphasizing the need for continued and comprehensive surveillance of this species.

Risk factors and molecular characterization of carbapenem resistant Escherichia coli recovered from a tertiary hospital in Fujian, China from 2021 to 2023

BackgroundThere is a serious public health concern regarding the emergence of carbapenem-resistant Escherichia coli (CREC). The purpose of this study is to identify the molecular characterization and risk factors of CREC in Fujian province, China.MethodsA total of 48 CREC isolates were collected from various clinical samples. The strains were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS). Susceptibility to antibiotics was determined by the standard broth microdilution method. Polymerase chain reaction (PCR) was used to screen common drug resistance genes. Multilocus sequence typing (MLST) was used to type isolates. RT-qPCR was used to detect gene expression of acrA, acrB, and tolC. Conjugation assays were used to analyze the transferability of plasmids carrying mcr-1 or blaNDM. Risk factors for CREC infection were identified by logistic regression analysis.Results48 CREC strains were collected, with 81.25% producing carbapenemase (CP-CREC), and 18.75% were not producing carbapenemase (no-CP-CREC). They belonged to 21 sequence type (STs) and five unknown STs. Perianal swabs were the main sample type, with 25 patients found to have hematological malignancies. All isolates of CP-CREC were found to contain blaNDM (blaNDM−5 (n = 32), blaNDM−1 (n = 5), blaNDM−4 (n = 1), and blaNDM−13 (n = 1)), among which one isolate co-existence blaNDM−5 and blaOXA−48. Two blaNDM-positive strains, specifically blaNDM−5 and blaNDM−4, were found to co-habor mcr-1 with ST617. Conjugation assays confirmed that blaNDM−1, blaNDM−13, and most blaNDM−5(68.75%, 22/32) could be transferred between E. coli strains. Four of the 9 non-CP-CREC isolates had deletions in ompC and ompF with blaCTX−M production, while the other five showed high expression of acrA, acrB, and tolC. Antibiotics usage, antifungal treatment, detection of other pathogens (prior to CREC infection), and respiratory disease were identified as independent risk factors for CREC infection. The area under the receiver operating characteristic curve for the scoring system was 0.937. Youden’s index, with sensitivity and specificity of 0.96 and 0.78, was maximal when 2 points were scored.ConclusionsIn CP-CREC, carbapenem resistance is caused primarily by multiple types of blaNDM, while non-CP-CREC is caused by loss of porin protein or high expression of efflux pumps coupled with carrying blaCTX−M. CREC isolates were highly diverse in terms of ST, with a total of 21 STs identified. Here, we first describe a clinical strain of CREC from China both mcr-1 and blaNDM −4 with ST617. An easy-to-use scoring system was developed to diagnose CREC infections.

One decade of point-prevalence surveys for carriage of extended-spectrum beta-lactamase-producing enterobacterales: whole genome sequencing based prevalence and genetic characterization in a large Dutch teaching hospital from 2013 to 2022

ObjectivesTo determine the prevalence, trends, and potential nosocomial transmission events of the hidden reservoir of rectal carriage of extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E).MethodsFrom 2013 to 2022, yearly point prevalence surveys were conducted in a large Dutch teaching hospital. On the day of the survey, all admitted patients were screened for ESBL-E rectal carriage using peri-anal swabs and a consistent and sensitive selective culturing method. All Enterobacterales phenotypically suspected of ESBL production were analysed using whole genome sequencing for ESBL gene detection and clonal relatedness analysis.ResultsOn average, the ESBL-E prevalence was 4.6% (188/4,119 patients), ranging from 2.1 to 6.6% per year. The ESBL-prevalence decreased on average 5.5% per year. After time trend correction, the prevalence in 2016 and 2020 was lower compared to the other year. Among the ESBL-E, Escherichia coli (80%) and CTX-M genes (85%) predominated. Potential nosocomial transmission events could be found in 5.9% (11/188) of the ESBL-E carriers.ConclusionsThe ESBL-E rectal carriage prevalence among hospitalized patients was 4.6% with a downward trend from 2013 to 2022. The decrease in ESBL-E prevalence in 2020 could have been due to the COVID-19 pandemic and subsequent countrywide measures as no nosocomial transmission events were detected in 2020. However, the persistently low ESBL-E prevalences in 2021 and 2022 suggest that the decline in ESBL-E prevalence goes beyond the COVID-19 pandemic, indicating that overall ESBL-E carriage rates are declining over time. Continuous monitoring of ESBL-E prevalence and transmission rates can aid infection control policy to keep antibiotic resistance rates in hospitals low.

To evaluate the performance of simultaneous amplification and testing assay for group B Streptococcus detection: comparison with real-time PCR and ddPCR assays

BackgroundTo evaluate the performance of simultaneous amplification and testing (SAT) assay for the detection of group B Streptococcus (GBS) in maternal vaginal and perianal swabs compared with real-time polymerase chain reaction (RT-PCR).MethodsWe obtained vaginal and perianal swabs from 1474 pregnant women at the Obstetrics and Gynecology Hospital of Fudan University (Shanghai, China) between April 2023 and June 2023. Vaginal and perianal swabs were collected at 35–37 weeks of gestation. Swabs were tested for GBS simultaneously by using the SAT assay and RT-PCR, and a comparative analysis (kappa coefficient) was performed. Furthermore, we conducted additional droplet digital PCR (ddPCR) tests to confirm the results when there were controversial results between SAT and RT-PCR. In addition, we compared the limit of detection, technical specificity, repeatability and reproducibility of SAT-GBS with those of routine RT-PCR assays.ResultsIn our study, the detection rate of clinical GBS according to the SAT assay was 11.5% (169/1471). The SAT assay showed a sensitivity of 91.8%, a specificity of 99.9%, a diagnostic accuracy of 98.9%, a positive predictive value (PPV) of 99.4% and a negative predictive value (NPV) of 98.8%. The kappa value between RT-PCR and SAT was 0.917.ConclusionsThis SAT assay for the detection of group B Streptococcus is not only easy to perform but can also detect GBS sensitively and specifically and may be used in the regular molecular diagnosis of GBS infection among pregnancies.

Gut colonization with multidrug resistant organisms in the intensive care unit: a systematic review and meta-analysis

BackgroundGut colonization with multidrug-resistant organisms (MDRO) frequently precedes infection among patients in the intensive care unit (ICU), although the dynamics of colonization are not completely understood. We performed a systematic review and meta-analysis of ICU studies which described the cumulative incidence and rates of MDRO gut acquisition.MethodsWe systematically searched PubMed, Embase, and Web of Science for studies published from 2010 to 2023 reporting on gut acquisition of MDRO in the ICU. MDRO were defined as multidrug resistant non-Pseudomonas Gram-negative bacteria (NP-GN), Pseudomonas spp., and vancomycin-resistant Enterococcus (VRE). We included observational studies which obtained perianal or rectal swabs at ICU admission (within 48 h) and at one or more subsequent timepoints. Our primary outcome was the incidence rate of gut acquisition of MDRO, defined as any MDRO newly detected after ICU admission (i.e., not present at baseline) for all patient-time at risk. The study was registered with PROSPERO, CRD42023481569.ResultsOf 482 studies initially identified, 14 studies with 37,305 patients met criteria for inclusion. The pooled incidence of gut acquisition of MDRO during ICU hospitalization was 5% (range: 1–43%) with a pooled incidence rate of 12.2 (95% CI 8.1–18.6) per 1000 patient-days. Median time to acquisition ranged from 4 to 26 days after ICU admission. Results were similar for NP-GN and Pseudomonas spp., with insufficient data to assess VRE. Among six studies which provided sufficient data to perform curve fitting, there was a quasi-linear increase in gut MDRO colonization of 1.41% per day which was stable through 30 days of ICU hospitalization (R2 = 0.50, p < 0.01).ConclusionsAcquisition of gut MDRO was common in the ICU and increases with days spent in ICU through 30 days of follow-up. These data may guide future interventions seeking to prevent gut acquisition of MDRO in the ICU.

Surveillance of carbapenem-resistant Klebsiella pneumoniae and Escherichia coli in perianal swab samples.

Our study aimed to detect carbapenem-resistant Klebsiella pneumoniae (CRKP) and/or carbapenem-resistant Escherichia coli in perianal swab samples, exploring their link to bloodstream infections (BSIs) in a tertiary-care university hospital. CRKP-related BSIs ranged from 3.7% to 9.58%, emphasizing the need to understand local risk factors for effective infection control.

Key microbial monitoring and clinical analysis of bloodstream infections and CRO colonization after hematopoietic stem cell transplantation in hematological patients

Objective: To investigate the distribution and clinical characteristics of pathogenic bacteria following hematopoietic stem cell transplantation (HSCT), as well as to provide a preliminary research foundation for key microbial monitoring, and clinical diagnosis and treatment of infections after HSCT in hematological patients. Methods: We retrospectively analyzed the clinical data of 190 patients who tested positive for microbial testing [G-bacteria blood culture and/or carbapenem-resistant organism (CRO) screening of perianal swabs] at our center from January 2018 to December 2022. Patients were divided into blood culture positive, perianal swab positive, and double positive groups based on the testing results. The three patient groups underwent statistical analysis and comparison. Results: The top four pathogenic bacteria isolated from sixty-three patients with G-bacteria bloodstream infection (BSI) were Escherichia coli (28 strains, 43.75% ), Klebsiella pneumonia (26 strains, 40.63% ), Pseudomonas aeruginosa (3 strains, 4.69% ), and Enterobacter cloacae (3 strains, 4.69% ). The top three pathogenic bacteria isolated from 147 patients with CRO perianal colonization were carbapenem-resistant Klebsiella pneumoniae (58 strains, 32.58% ), carbapenem-resistant Escherichia coli (49 strains, 27.53% ), and carbapenem-resistant Enterobacter cloacae (20 strains, 11.24% ). The 3-year disease-free survival (DFS ) and overall survival (OS) of double positive group patients were significantly lower compared to those in the blood culture and perianal swab positive groups (DFS: 35.6% vs 53.7% vs 68.6%, P=0.001; OS: 44.4% vs 62.4% vs 76.9%, P<0.001), while non-relapse mortality (NRM) was significantly higher (50.0% vs 34.9% vs 10.6%, P<0.001). Failed engraftment of platelets and BSI are independent risk factors for NRM (P<0.001). Using polymyxin and/or ceftazidime-avibactam for more than 7 days is an independent protective factor for NRM (P=0.035) . Conclusion: This study suggests that the occurrence of BSI significantly increases the NRM after HSCT in patients with hematological diseases; CRO colonization into the bloodstream has a significant impact on the DFS and OS of HSCT patients.

Social and clinical predictors of perianal colonisation by multidrug-resistant bacteria for geriatric patients in the internal medicine service.

Colonisation by multidrug-resistant (MDR) bacteria is a global health issue. The identification of patients with a higher risk of colonisation is essential. Patients admitted to internal medicine services might represent a vulnerable population with a high risk of colonisation. This study was the first to assess social and clinical variables associated with a higher risk of perianal colonisation by MDR bacteria in a Spanish cohort of patients admitted to internal medicine service. Patients admitted to an internal medicine service during 12months of recruitment (1 March 2022 to 1 March 2023) were included in the study. Perianal swabs were performed at admission to identify the presence of MDR bacteria. Social and clinical variables were collected following a directed acyclic graph. A cluster analysis was performed to identify clinical profiles of higher risk. Bivariate analyses and multivariable logistic regression models were fitted to identify potential predictors of MDR bacteria colonisation. A total of 245 patients, according to the required sample size, were included. Of them, 46 (18.8%) were colonised by MDR bacteria in perianal swabs. Female sex, age > 80years, dependency on activities of daily living, cognitive deterioration and living in long-term care facilities constituted the highest risk clinical profile. After adjustments, living in long-term care facilities and malnutrition remained the main risk factors identified. Patients admitted to internal medicine services presented a high frequency of perianal colonisation by MDR bacteria. Social and clinical variables associated with bio-psycho-social susceptibility were associated with colonisation. Special surveillance is needed in internal medicine services to control the transmission.

Epidemiology and molecular typing of multidrug-resistant bacteria in tertiary hospitals and nursing homes in Flanders, Belgium.

This study aimed to map MDRO carriage and potential transmission within and between three Flemish tertiary care hospitals and their neighbouring nursing homes. A cross-sectional MDRO prevalence survey was organized between October 2017 and February 2019. Perianal swabs were cultured for detection of MDRO. Determination of clonal relatedness based on wgMLST allelic profiles was performed. The prevalence of MDRO in Belgian hospitals and NHs is on the rise, compared to previous studies, and transmission in and between institutions is observed. These results re-emphasize the need for a healthcare network-wide infection prevention strategy in which WGS of MDRO strains can be supportive.

Epidemiology of extended-spectrum β-lactamase–producing Enterobacterales infection in kidney transplant recipients

BackgroundExtended-spectrum b-lactamase (ESBL)-producing gram-negative bacilli (ESBL-GNB) are the most important pathogenic bacteria infecting kidney transplant patients. Kidney transplantation has been shown to be a risk factor for nosocomial ESBL-GNB bacteremia. The aims of this study were to describe the epidemiology of ESBL-GNB acquisition and to identify factors associated with ESBL-GNB infection in kidney transplant recipients, including pretransplant ESBL-GNB fecal carriage.MethodsA prospective study of patients undergoing kidney transplantation at Ramathibodi Hospital from March 1, 2019–November 30, 2020 was conducted. During this period, 66 patients who underwent kidney transplantation. Perianal swab cultures and urine cultures for ESBL-GNB were obtained from all subjects upon admission for transplantation and on Days 3, 7, 14 and 21 after surgery to determine the prevalence, incidence, and duration of admission before acquisition of the organisms.ResultsOf the 66 patients undergoing kidney transplantation, 18 preoperative perianal swabs were detected to be positive for ESBL-GNB upon admission, representing 27.3% of the cases. The in-hospital perianal swab tests showed a significant increase to 96.8% positive ESBL-GNB cultures at the end of week 3. Approximately one-fourth (27.8%) of patients who acquired ESBL-GNB developed a postoperative symptomatic infection. The infection occurred in 13% of such patients who were not ESBL positive at first. These infections included urinary tract infections (20 cases, [30%], of which 55% were due to ESBL-GNB) and bloodstream infections (13 cases; of which 9 [69.2%] were due to ESBL-GNB). E. coli was the most common pathogen. Previous exposure to antibiotics, including surgical prophylaxis, underlying disease, duration of indwelling urinary catheters and ureteric stents, as well as other operative factors were not found to be significantly associated with the acquisition of ESBL-producing organisms in this dataset.ConclusionsESBL carriage may be a risk factor for the development of bacteremia and other serious infections among kidney transplant recipients, although a statistically significant difference could not be demonstrated owing to the small size of the sample. The high rate of ESBL acquisition suggests that more stringent infection prevention and control efforts are needed.

Diagnosis of canine intestinal parasites: Improved detection of Dipylidium caninum infection through coproantigen testing

Intestinal parasites, including cestodes like Dipylidium caninum, are common in dogs in the United States of America (USA), but fecal flotation consistently, and, at times, dramatically, fails to identify many of these infections. To determine the extent to which including coproantigen testing for D. caninum would improve the identification of dogs infected with this cestode, we evaluated fecal samples from 877 dogs (589 pet and 288 from municipal shelters) from six USA states using zinc sulfate (specific gravity 1.24) fecal flotation with centrifugation along with coproantigen detection for Giardia sp., hookworms, ascarids, and Trichuris vulpis. For D. caninum, PCR of perianal swabs was included. Intestinal parasite infections were identified, using centrifugal fecal flotation or coproantigen, in 265 dogs (13.2 % pet, 64.9 % shelter). Dipylidium caninum infection was detected in 5.6 % of dogs with the combination of coproantigen and centrifugal fecal flotation, and 7.3 % of dogs when perianal swab results were included; prevalence varied by diagnostic method, population, and geographic region. In pet dogs, D. caninum infection was identified by fecal flotation (0), coproantigen (2.2 %), or perianal swabs (1.2 %). The same methods revealed infection in 0.3 %, 12.5 %, and 11.1 % of shelter dogs, respectively. Frequent use of praziquantel in shelter dogs (116/288; 40.3 %) may have reduced prevalence. Positive and negative agreement of D. caninum coproantigen with perianal swab PCR in pet dogs was 85.7 % and 98.8 %, respectively. Multiple logistic regression analysis accounting for region, population, and age found D. caninum infection to be more common in shelter dogs relative to pet (adjusted OR 4.91 [2.48, 10.24]) and in the Southcentral and Southeast regions relative to North (adjusted OR 9.59 [1.92, 174.13] and 17.69 [3.67, 318.09] respectively). Coproantigen testing also enhanced the detection of other intestinal parasites over fecal flotation alone, including Giardia sp. (14.7 % vs 3.3 %), hookworms (13.8 % vs 8.4 %), ascarids (2.9 % vs 2.2 %), and T. vulpis (2.9 % vs 1.4 %). Together, these data indicate that the coproantigen assay employed increases detection of D. caninum infections several fold, supporting the use of this test in clinical practice, and add to a growing body of research documenting enhanced diagnosis through implementation of multiple laboratory-based methods.

Immunoassay for detection of Dipylidium caninum coproantigen in dogs and cats.

Dipylidium caninum infections in dogs and cats are underestimated because of a lack of proglottid observations and poor recovery of parasite elements by centrifugal flotation. We developed an immunoassay that employs a pair of monoclonal antibodies to capture D. caninum-specific coproantigen in fecal extracts from dogs and cats. Real-time PCR for D. caninum DNA in perianal swabs and observation of proglottids were used as reference methods. In 6 experimentally infected dogs, parasite DNA, coproantigen, and proglottid segments were first detected at 22, 23, and 26 d post-infection, respectively. Praziquantel treatment of 3 experimentally infected dogs resulted in the elimination of both coproantigen and proglottid shedding within 1-5 d post-treatment; however, parasite DNA persisted for 14 d. Immunohistochemistry on immature and mature tapeworm segments using an antibody against the coproantigen supports the premise that the antigen is produced in mature segments. We assessed the performance of our coproantigen test in natural infections in 78 dogs from a flea-endemic area. Of the 12 antigen-positive samples, 11 were confirmed with a positive PCR test and/or proglottid observation. Finally, we evaluated a convenience sample set of 730 canine and 163 feline fecal samples obtained from a commercial diagnostic laboratory; D. caninum antigen was detected in 4.1% of the canine and 12.9% of the feline samples, whereas parasite elements were observed in only 0.028% of samples. Our coproantigen immunoassay provides a sensitive method for the detection of D. caninum infection in dogs and cats.

Prevalence and influencing factors of human soil-transmitted nematode infections in Ningbo City from 2016 to 2021

To investigate the prevalence and influencing factors of soil-transmitted nematode infections in Ningbo City from 2016 to 2021, so as to provide insights into the development of targeted control measures against soil-transmitted nematodiasis. Permanent residents at ages of 3 years and older were sampled in Ningbo City using a multi-stage sampling method each year during the period from 2016 to 2021. Soil-transmitted nematode eggs were detected in stool samples using a modified Kato-Katz thick smear method (two slides for each stool sample), and Enterobius vermicularis eggs were additionally identified among children at ages of 3 to 12 years using the adhesive cellophane-tape perianal swab method. The time- and regions-specific prevalence of soil-transmitted nematode infections was calculated, and the factors affecting hookworm infections were identified using a multivariate logistic regression model. A total of 11 573 person-times were detected for soil-transmitted nematode infections in Ningbo City from 2016 to 2021, and 296 egg-positives were detected, with a mean prevalence rate of 2.56% [95% confidential interval (CI): (2.28%, 2.87%)]. Hookworm was the predominant species of soil-transmitted nematode among egg-positives in Ningbo City (98.31%, 291/296), and there was a significant difference in the prevalence of hook-worm infections among years (χ2 = 190.27, P < 0.01). The highest prevalence of hook-worm infections was observed in Ninghai County (4.06%), and there was a region-specific prevalence rate of hookworm infection in Ningbo City (χ2 = 148.43, P < 0.01). Multivariate logistic regression analysis showed that elderly residents at ages of over 60 years [odds ratio (OR)= 1.94, 95% CI: (1.07, 3.54), P < 0.05], males [OR = 2.19, 95% CI: (1.72, 2.80), P < 0.01], farmers [OR = 6.94, 95% CI: (3.37, 14.29), P < 0.01] and residents with a low education level [illiteracy or semi-illiterate: OR = 3.82, 95% CI: (1.56, 9.35), P < 0.05; primary school: OR = 2.70, 95% CI: (1.11, 6.59), P < 0.05] were at a higher risk for hookworm infections. The overall prevalence of soil-transmitted nematode infections was low among residents in Ningbo City from 2016 to 2021. The surveillance and health education for human hookworm disease remain to be reinforced among male farmers with a low education level at ages of over 60 years in Ninghai County.

Development of a Risk Prediction Model of Subsequent Bloodstream Infection After Carbapenem-Resistant Enterobacteriaceae Isolated from Perianal Swabs in Hematological Patients.

Patients with hematological diseases are at high risk of carbapenem-resistant Enterobacteriaceae (CRE) infection, and CRE-related bloodstream infection (BSI) is associated with high mortality risk. Therefore, developing a predictive risk model for subsequent BSI in hematological patients with CRE isolated from perianal swabs could be used to guide preventive strategies. This was a single-center retrospective cohort study at a tertiary blood diseases hospital, including all hematological patients hospitalized from 10 October 2017 to 31 July 2021. We developed a predictive model using multivariable logistic regression and internally validated it using enhanced bootstrap resampling. Of 421 included patients with CRE isolated from perianal swabs, BSI due to CRE occurred in 59. According to the multivariate logistic analysis, age (OR[odds ratio]=1.04, 95% CI[confidence interval]: 1.01-1.06, P=0.004), both meropenem and imipenem minimal inhibitory concentration (MIC) of the isolate from perianal swabs>8ug/mL (OR=5.34, 95% CI: 2.63-11.5, P<0.001), gastrointestinal symptoms (OR=3.67, 95% CI: 1.82-7.58, P<0.001), valley absolute neutrophil count (109/L)>0.025 (OR=0.07, 95% CI: (0.02-0.19, P<0.001) and shaking chills at peak temperature (OR=6.94, 95% CI: (2.60-19.2, P<0.001) were independently associated with CRE BSI within 30 days and included in the prediction model. At a cut-off of prediction probability ≥ 21.5% the model exhibited a sensitivity, specificity, positive predictive value and negative predictive value of 79.7%, 85.6%, 96.27% and 47.47%. The discrimination and calibration of the prediction model were good on the derivation data (C-statistics=0.8898; Brier score=0.079) and enhanced bootstrapped validation dataset (adjusted C-statistics=0.881; adjusted Brier score=0.083). The risk prediction model is freely available as a mobile application at https://liujia1992.shinyapps.io/dynnomapp/. A prediction model based on age, meropenem and imipenem MIC of isolate, gastrointestinal symptoms, valley absolute neutrophil count and shaking chills may be used to better inform interventions in hematological patients with CRE isolated from perianal swabs.

Emergence of OXA-484-Producing Klebsiella variicola in China.

The frequent and inappropriate use of antibiotics has caused a dramatic rise in the number, species, and degree of multi-drug resistant bacteria, making them more prevalent and difficult to treat. In this context, the aim of the present study was to characterize the OXA-484-producing strains isolated from a perianal swab of a patient by using whole-genome analysis. In this study, carbapenemase-producing Klebsiella variicola was identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), average nucleotide identity (ANI) and PCR. S1 nuclease pulsed-field gel electrophoresis (S1-PFGE) and Southern blotting were utilized to characterize the plasmid profiles of K. variicola 4717. In particular, WGS was performed to obtain genomic information on this clinical isolate, and assemble all the plasmids of the bla OXA-484-harboring strain. The antimicrobial susceptibility pattern of K. variicola 4717 revealed that it was resistant to a range of antibiotics, including aztreonam, imipenem, meropenem, ceftriaxone, cefotaxime, ceftazidime, levofloxacin, ciprofloxacin, piperacillin-tazobactam, methylene-sulfamer oxazole, amoxicillin-clavulanic acid, cefepime, and tigecycline. Its susceptibility to chloromycin was intermediate, while it was still susceptible to amikacin, gentamicin, fosfomycin, and polymyxin B. The presence of two companion plasmids, p4717_1 and p4717_2, together with a plasmid carrying the bla OXA-484 gene was observed. An in-depth investigation of p4717-OXA-484 uncovered that it is an IncX3-type plasmid and shares a similar segment encoded by IS26. Given the similar genetic background, it was conceivable that bla OXA-484 could have developed from bla OXA-181 through a series of mutations. Herein, we described the first genome sequence of K. variicola strain harbouring the class D β-actamase bla OXA-484 in an Inc-X3-type plasmid. Our work also uncovered the genetic characterization of K. variicola 4717 and the importance of initiating antimicrobial detection promptly.

Positive rates for Enterobius vermicularis eggs among preschool children in Yeosu-si, Jeollanam-do, Korea (2017-2021).

This study aimed to evaluate the positive rates for Enterobius vermicularis eggs among preschool children in Yeosu-si, Jeollanam-do, the Republic of Korea (Korea) over a period of 5 years (2017-2021). Perianal swab samples, obtained using cellotape, from 10,392 preschool children in 26 districts were examined microscopically for E. vermicularis eggs. The test results were notified through the local health center, and the families of children who tested positive were advised to provide them anthelmintics treatment. The annual positive rates were 5.0%, 5.2%, 4.4%, 2.2%, and 1.0% in 2017, 2018, 2019, 2020, and 2021, respectively. The overall positive rate was higher in boys than in girls (P< 0.05), and children aged 5-7 years were at a higher risk of being infected than those aged 0-4 years (P< 0.05). Although the rates of infection by E. vermicularis in the survey area, Yeosu-si, were still in the 1% range , the results of this study suggest that they can be significantly reduced through continuous intervention centered around the test-treatment strategy.

Is pinworm infection still a public health concern among children in resource-rich regions? Trends in pinworm infection prevalence and associated factors among children in Hualien County, Taiwan: a retrospective cross-sectional study

BackgroundEnterobius vermicularis (pinworm) is a common intestinal parasitic infection in children. A gradual decrease in the prevalence of pinworm infection has been noted in resource-rich settings, such as Taiwan. However, the influence of sociodemographic factors on the temporal trend in pinworm infection rates in children under the current pinworm infection prevention policy in Taiwan is not well characterized. This study aimed to evaluate the trend of pinworm infection prevalence and the associated factors among children in Hualien County, Taiwan.MethodologyIn this retrospective cross-sectional study, we included a total of 56,197 students (aged 6–10 years) in grades 1 and 4 in Hualien in 2009–2018. Children were screened for pinworm infection using adhesive cellophane perianal swabs in the routine student health examination. Logistic regression was conducted to evaluate the factors associated with pinworm infection. Associations between dependent and independent variables were measured by odds ratios. The Cochran–Armitage test was used to assess whether there were significant trends in different stratifications. Variables with P-values < 0.05 were considered statistically significant.ResultsA total of 56,197 school-age children from grades 1 and 4 during 2009–2018 were included. Young age and male sex were risk factors for pinworm infection (P < 0.001). A negative correlation between body mass index and enterobiasis was observed, and decreased pinworm infection was noted during the study reference period. Children living in suburban and rural areas had higher odds of having a pinworm infection than those living in urban areas (P < 0.001). A significant decrease in the overall prevalence rate of pinworm infection was observed among children in 2009–2018 (P < 0.001). However, there was no obvious change in the pinworm infection rate in rural areas during this period (P = 0.953), and it was higher than that in urban and suburban areas.ConclusionsThe overall prevalence of pinworm infection gradually decreased from 2009 to 2018 among school-age children in Hualien. However, there was no declining trend in pinworm infection in rural areas. Young age, male sex, and rural residence were significantly associated with pinworm infection. Pinworm infection remains a major public health concern among children in rural areas of Hualien.

Evaluation of Faecal Carriage of Carbapenem-Resistant Enterobacteriaceae among Patients Admitted in an Intensive Care Unit of a Tertiary Care Hospital

BACKGROUND&#x0D; Association of man with the microbial world have found to be co-existed since old ages. Out of these microbial agents, some bacteria which provide a symbiotic balance, leading to a protective and stabilizing effect on the body, are known as resident microbes. On the other hand, some bacteria which invade and grow in man’s tissues causing diseases, damages and sometimes death, are known as pathogenic bacteria. This study was performed to evaluate the carbapenem resistance pattern among the patients admitted to an ICU in the Accident and Emergency departments.&#x0D; METHODS&#x0D; Rectal/ perianal swabs were taken from patients who were admitted to the intensive care unit (ICU) of the accident and emergency department. Swabs were collected first on the day of admission, then on day 4, and thereafter weekly while they were admitted in the ICU to monitor the resistance pattern among ICU patients.&#x0D; RESULTS&#x0D; A total of 100 rectal/ perianal swabs were collected from 89 patients on different days of admission to the ICU. Out of these 89 patients, CRE, i.e. E. coli or Klebsiella species were obtained from 35 patients. Now from these 35 patients, the samples were collected on day 1, day 4, and day 7 of admission. Then, out of these 35 patients, carbapenem-resistant Klebsiella pneumoniae and E. coli isolates were recovered from 35 (39.3%) patients i.e. Klebsiella pneumoniae isolates from fifteen patients and carbapenem-resistant E. coli isolates from twenty patients.&#x0D; CONCLUSIONS&#x0D; Carbapenems were earlier considered as the last-resort antibiotics for the treatment of infections caused by multidrug-resistant gram-negative bacteria. But, due to non-judicious use of carbapenems in clinical settings, the emergence of carbapenem-resistant organisms has become a big threat of concern to human health.

P432 Detection of erg11 gene mutation in fluconazole resistant Candida albicans isolates

Poster session 3, September 23, 2022, 12:30 PM - 1:30 PMObjectiveTo determine the profile of fluconazole-resistant Candida isolates (FRCS) and the proportion of erg11 gene mutation in fluconazole-resistant C. albicans (FRCA) isolatesMethodsAfter getting approval from ethics the study was conducted on 150 isolates of FRCS obtained from patients admitted to our tertiary care hospital from September 2019 to December 2021. All the isolates were revived onto Sabouraud dextrose agar (SDA) and identified by Matrix-Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS). Fluconazole-resistance was detected by VITEK 2 automated system. Deoxyribonucleic acid (DNA) of FRCA isolates were extracted by QIAamp DNA Mini kit (Qiagen-51 304, Hilden, Germany) as per manufacturer's instruction. A single primer pair targeting the nucleotide sequence from 1067 to 1576 bp region of erg11 gene was used for amplification as per Xu et al. with minor modification and 500 bp polymerase chain reaction (PCR) products were observed by gel electrophoresis. A positive clinical isolate of FRCA was used as a positive control. The PCR products were purified and subjected to Sanger sequencing with an ABI PRISM DNA analyzer (Applied Biosystems) and mutations were detected by using Mega (version 7) software by comparing with the published GenBank sequence AF153844.1 of C. albicans strain ATCC 28516. Categorical variables were expressed in percentages and continuous variables were expressed in mean (average).ResultsOut of the total of 150 FRCS, the most common fluconazole-resistant agent of candidiasis was C. auris, which was isolated from 60 (40%) cases followed by 24 (16%) isolates of C. glabrata, 19 (12.7%) isolates of C. krusei, 18 (12%) isolates of C. parapsilosis, 17 (11.3%) isolates of C. albicans, 10 (6.7%) isolates of C. tropicalis, and only two (1.3%) isolates of C. guilliermondii. Among these 17 FRCA isolates, 9 isolates were obtained from genital swabs, 5 from blood, and a single isolate each from the perianal swab, ear swab, and sputum. A total of 12 (70.6%) out of 17 FRCA isolates yielded 500 bp region in erg11 gene. Gel electrophoresis image of PCR products of erg11 gene is depicted in Figure 1. Sequencing of these products detected a single missense mutation A1309G (V437I) in one FRCA isolate. Most of the FRCA isolates had an average of 4 silent mutations (observed in 6 isolates) and a single isolate had 6 silent mutations. A total of 8 different silent mutations were observed among FRCA isolates T1296C (83.3%), C1203T (66.7%), A1440G (66.7%), C1302T (50%), T1470C (50%), T1140C (25%), T1110C (16.7%), and T1284C (8.3%).Conclusion C. auris was the most common fluconazole resistant isolate observed, followed by C. glabrata, C. krusei, C. parapsilosis, C. albicans, C. tropicalis, and C. guilliermondii. There were many silent mutations observed in erg11 gene of FRCA isolates and detected only a single missense mutation (V437I). Fluconazole-resistant in FRCA isolates may be due to mechanisms other than the studied one in our region.

Characterization of antigens of Enterobius vermicularis (pinworm) eggs

Enterobiasis (pinworm infection) caused by Enterobius vermicularis is a common parasitic infection prevalent worldwide especially in children. Infection is diagnosed by microscopic detection of E. vermicularis eggs on perianal swabs. This study aimed to characterize the antigens of E. vermicularis eggs as a preliminary step towards identifying diagnostic targets for detection in infected individuals. The study was conducted between October 2019 and February 2020, following approval from Ethics Review Committee of the Faculty of Medicine, University of Colombo (EC-19-034). E. vermicularis eggs were harvested from perianal swabs using acetone and purified with 1× PBS (pH 7.2). A portion of eggs was used for preparing antigen slides, while the rest were sonicated and vortexed with glass beads and inoculated subcutaneously (with weekly booster doses) into a Wistar rat for developing antibodies. Blood drawing from rat was done weekly for 5 weeks. Confirmation of the presence of antibodies was done by surface immunofluorescence against eggs on the antigen slides. Protein bands were determined using SDS-PAGE assay and immunogenic antigen bands were determined by reacting with antiserum after immunoblotting. The band sizes of the proteins were determined against corresponding bands of a protein ladder. Surface immunofluorescence was positive with serum obtained from day 14 post-inoculation from the Wistar rat as well as that obtained from a person with chronic enterobiasis. The most prominent and immunogenic protein bands identified from egg antigens were 21 kDa, 66 kDa, 83 kDa, 96 kDa, 112 kDa, 121 kDa, 140 kDa and 151 kDa. Methods used in this study were effective in obtaining E. vermicularis egg antigens which were immunogenic. Furthermore, surface antigens of intact eggs reacted with antibodies developed against crushed egg antigens. These findings may pave the way for the development of effective immunodiagnostics.