BD MAX Research Articles

Performance Evaluation of the LabGenius C-CT/NG-BMX Assay for Chlamydia trachomatis and Neisseria gonorrhoeae Detection.

The LabGenius C-CT/NG-BMX assay (LabGenius CT/NG; BIOMEDUX, Gyeonggi, Republic of Korea) is a recently developed real-time PCR assay that can simultaneously detect the sexually transmitted pathogens Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) in genitourinary specimens. We evaluated the analytical performance of this assay in comparison with BD MAX CT/GC/TV (Becton Dickinson, Franklin Lakes, NJ, USA). The results of both assays were in nearly perfect agreement for the detection of CT and NG. LabGenius CT/NG demonstrated acceptable analytical performance, comparable with that of another commercially available kit, and provides a cost-effective option for detecting sexually transmitted pathogens in routine and follow-up testing.

A-278 Prevalence of Clostridium Difficile in Long-Term Care Facilities Using BD Max Cdiff Molecular Assay

Abstract Background Clostridium difficile (C.Diff) is a gram positive anaerobe producing Enterotoxin and Cytotoxin (toxin A and B respectively); more than half of million infection is diagnosed yearly with more than 10% of the cases are in patients over 65 years old. Residents in Long-Term Care Facilities (LTCF) are more prone to have C. Diff infection (CDI) because of their age, the frequent use of antibiotics, fragilities, co-morbidity, and living environment. Diagnosing CDI is based on clinical signs and symptoms as well as laboratory tests; however, the enzyme immunoassays are reliable, the tissue culture cytotoxicity is labor intensive. The nucleic acid amplification tests are becoming more the standard as first step in the diagnosis. The BD MAX™ System is a PCR walkaway instrument that provides the sensitivity, specificity and faster turnaround for the C. diff. Methods The BD MAX™ System is an automated in-vitro diagnostic test for the direct qualitative detection of the C. difficile toxin B gene (tcdB) in human liquid or soft stool specimens from patients suspected of having Clostridium difficile Infection (CDI). Premier Toxins A & B is an enzyme immunoassay for the direct detection of Clostridium difficile toxin A and toxin B in stool samples. We collected data from 5,267 samples were collected from resident in LTCF and were run using the EIA assay, 275 samples were ran using the BD Max molecular assay. We had 31 samples that were run using both assays. Statistical analyses were done using Analyse-it. Results Female accounted for 60% of the patients tested; the positivity rate was 13.2% for female and 17.2 for male using the EIA. The positivity rate was 19.2% for female and 30.6% for male when using the molecular assay. The agreement between the EIA and the PCR was 87% based on 31 samples that were run for both assays. Conclusions The BD Max gave the benefit of a fully automated with high sensitivity and specificity for the presence of toxin B producing C. Diff. The difference between the methods could be due to the lack of the sensitivity in the EIA and the fact that the molecular assay might be picking up colonized specimen or the beginning or end of infection. However, the ability to diagnose CDI early and prevent spreading of the disease to other patients is a huge benefit to the facilities. We have to keep in mind also that C.diff infection can be prevented with appropriate use of antibiotics and implementing antibiotic stewardship and infection control plan to prevent and stop spreading of the infection.

Diagnostic Accuracy of BD MAX MDR-TB Assay Performed on Bronchoscopy Specimens in Patients with Suspected Pulmonary Tuberculosis

Diagnostic Accuracy of BD MAX MDR-TB Assay Performed on Bronchoscopy Specimens in Patients with Suspected Pulmonary Tuberculosis

Clinical Performance of the BD Respiratory Viral Panel for BD MAX™ System in Detecting SARS-CoV-2, Influenza A and B, and Respiratory Syncytial Virus

Using a nasopharyngeal (NP) or anterior nasal (NS) swab from prospectively collected or retrospective specimens, we assessed the clinical performance of the BD Respiratory Viral Panel (BD RVP) for BD MAX System against FDA-cleared or authorized comparators. Across prospective and retrospective specimens, positive percent agreement (PPA) was ≥ 98.4% for SARS-CoV-2, ≥ 96.7% for influenza (flu) A, ≥ 91.7% for respiratory syncytial virus (RSV), and 100% for flu B (retrospective only) while negative percent agreement (NPA) was ≥ 97.7% across all targets, leading to the assay FDA clearance. A head-to-head comparison of NS versus NP results with BD RVP was also performed; PPA was ≥ 90% and NPA ≥ 98.2% for SARS-CoV-2, flu A and RSV. These findings confirm that the BD MAX RVP assay performs well for detection and differentiation of the three viruses in NP and NS specimens, with strong interrater agreements for NS versus NP comparisons.

BD Vaginal Panel assay results on the high-throughput BD COR system compared to the BD MAX system.

Molecular-based assays demonstrate excellent sensitivity for the detection of vaginitis causes. Here, the high-throughput BD Vaginal Panel for BD COR System (VP-COR) performance was compared to that of the predicate, BD MAX Vaginal Panel for BD MAX System (VP-MAX). Clinical or contrived samples were used to determine the agreement between VP-COR and VP-MAX. Acceptance criteria for VP-COR agreement were as follows: bacterial vaginosis (BV) required a positive percent agreement (PPA) point estimate of ≥95% and a negative percent agreement (NPA) point estimate of ≥98%; Candida group, Candida glabrata, Candida krusei, and Trichomonas vaginalis (TV) required a PPA and NPA point estimate of ≥95% [with lower bound of 95% confidence interval (95% CI) ≥90%]. PPA was 99.5% (95% CI: 97.5-100) and 97.9% (95% CI: 96.5-98.8) for BV contrived (n = 516) and BV clinical (n = 1,050) specimens, respectively. For the Candida group (clinical; n = 724), C. glabrata (contrived; n = 544), C. krusei (contrived; n = 522), and TV (clinical; n = 702), PPA was 99.4% (95% CI: 98.0-99.9), 100% (95% CI: 97.9-100), 100% (95% CI: 97.6-100), and 99.7% (95% CI: 98.3-100), respectively; the lowest lower bound CI value was 97.6%. NPA was >95% for BV contrived and BV clinical specimens. For the Candida group, C. glabrata, C. krusei, and TV, NPA was ≥98.9%; the lowest lower bound CI value was 97.3%. These results demonstrate the equivalent performance of the VP-COR assay when compared to VP-MAX.IMPORTANCEVaginitis is common among women of reproductive age, resulting in around 10 million office visits a year. Diagnosis is often difficult due to its multiple causes-including bacterial vaginosis, vulvovaginal candidiasis, and trichomoniasis-as well as variation in symptom presentation. Typically, cases are identified with a combination of symptomology, medical history, physical examination, and office- or laboratory-based testing. These traditional techniques involve subjective elements and demonstrate varying sensitivity and specificity. Inaccurate or delayed diagnosis leads to continued symptoms, repeat visits, inappropriate treatment, and unnecessary costs. Alternatively, the use of molecular-based assays increases sensitivity for the detection of vaginitis causes. With the validation of the vaginal panel molecular assay on COR (a high-throughput platform), a workflow can be streamlined in high-demand laboratories while providing high sensitivity for vaginitis detection.

A novel molecular assay conducted on the BD Max system to facilitate reflex testing for vanA and vanB in clinical isolates of enterococci

Infections caused by vancomycin-resistant enterococci (VRE) are common. Real-time PCR assays targeting vanA and vanB facilitate screening of patients in healthcare settings to limit the risk of dissemination, especially amongst those at high-risk of infection or with limited treatment options. Such assays are commonly performed as reflex testing procedures where they augment phenotypic techniques and shorten turnaround time to benefit timely clinical management. 'Random access' and 'sample-to-result' real-time PCR platforms are suited for this application as they are of low complexity and less technically demanding. Modelled on these attributes, we configured a real-time PCR assay (VRE BD) for detection of vanA/B in clinical isolates of enterococci, adapted for the BD Max System (Becton Dickinson). We applied an unconventional approach by testing suspensions of microorganisms in water to circumvent the traditional pre-analytical genomic extraction process. Our objective of this study was to assess the performance of this assay for detection of VRE in cultures by validating against a traditional real-time PCR assay based on the LightCycler 2.0 platform (Roche, VRE RO). A high level of analytical sensitivity and specificity (≥99.0%) for both genes was obtained when testing suspensions derived from blood agar. Results for suspensions obtained from chromID VRE (Edwards Group) showed a similar level of performance for vanA detection (100%), but not for the vanB target (≥90.9%) where a lesser number of isolates were available for testing. However, our results for VRE detection in isolates from these media were repeatable and reproducible, and equated to positive and negative predictive values of ≥95.2% and ≥97.8%, respectively. Furthermore, the VRE BD assay was also able to accurately detect VRE in clinical and spiked BacT/ALERT (bioMérieux) blood cultures. Thus, the technical simplicity, short turnaround time and robustness of this high performing assay for VRE is suitable for reflex testing. In addition, the format developed for the BD Max platform has potential application for reflex testing other molecular targets of clinical importance.

Performance of the BD MAX MDR-TB assay in a clinical setting and its impact on the clinical course of patients with pulmonary tuberculosis: a retrospective before-after study.

Missing isoniazid (INH) resistance during tuberculosis (TB) diagnosis can worsen the outcomes of INH-resistant TB. The BD MAX MDR-TB assay (BD MAX) facilitates the rapid detection of TB and INH and rifampin (RIF) resistance; however, data related to its performance in clinical setting remain limited. Moreover, its effect on treatment outcomes has not yet been studied. We compared the performance of BD MAX for the detection of INH/RIF resistances to that of the line probe assay (LPA) in patients with pulmonary TB (PTB), using the results of a phenotypic drug sensitivity test as a reference standard. The treatment outcomes of patients who used BD MAX were compared with those of patients who did not. Of the 83 patients included in the study, the BD MAX was used for an initial PTB diagnosis in 39 patients. The sensitivity of BD MAX for detecting PTB was 79.5%. The sensitivity and specificity of BD MAX for INH resistance were both 100%, whereas these were 50.0% and 95.8%, respectively, for RIF resistance. The sensitivity and specificity of BD MAX were comparable to those of LPA. The BD MAX group had a shorter time interval from specimen request to the initiation of anti-TB drugs (2.0 days vs. 5.5 days, p=0.001). BD MAX showed comparable performance to conventional tests for detecting PTB and INH/RIF resistances. The implementation of BD MAX as a diagnostic tool for PTB resulted in a shorter turnaround time for the initiation of PTB treatment.

Experience with PCR Testing for Enteric Bacteria and Viruses of Emergency Department Patients with Acute Gastroenteritis: Are There Implications for the Early Treatment of Clostridioides difficile Infection?

Early identification of acute gastroenteritis (AGE) pathogens via PCR may improve the management of patients presenting to the emergency department (ED). In this study, we evaluated the implementation of a testing algorithm for ED patients with AGE using the BD MAX automated PCR system. Data from 133 patients were analyzed. A total of 56 patients (42%) tested positive via PCR for at least one bacterial or viral pathogen. The median time to report PCR results was 6.17 h compared to 57.28 h for culture results for bacterial pathogens. The most common pathogen was Clostridioides difficile (n = 20, 15%). In total, 14 of the 20 C. difficile-positive patients were aged >65 years and 17 of the 20 patients (85%) were diagnosed with a clinically relevant infection based on typical symptoms and laboratory values. They received antibiotics, mostly oral vancomycin, starting a median of 11.37 h after ED admission. The introduction of PCR for the diagnosis of AGE infection in patients presenting to the ED may have the greatest impact on the rapid identification of C. difficile and the timely administration of antibiotics if necessary.

The role of the plasmid-mediated fluoroquinolone resistance genes as resistance mechanisms in pediatric infections due to Enterobacterales.

Fluoroquinolones (FQs) are not commonly prescribed in children, yet the increasing incidence of multidrug-resistant (MDR) Enterobacterales (Ent) infections in this population often reveals FQ resistance. We sought to define the role of FQ resistance in the epidemiology of MDR Ent in children, with an overall goal to devise treatment and prevention strategies. A case-control study of children (0-18 years) at three Chicago hospitals was performed. Cases had infections by FQ-susceptible, β-lactamase-producing (bla) Ent harboring a non- or low-level expression of PMFQR genes (PMFQS Ent). Controls had FQR infections due to bla Ent with expressed PMFQR genes (PMFQR Ent). We sought bla genes by PCR or DNA (BD Max Check-Points assay®) and PMFQR genes by PCR. We performed rep-PCR, MLST, and E. coli phylogenetic grouping. Whole genome sequencing was additionally performed on PMFQS Ent positive isolates. Demographics, comorbidities, and device, antibiotic, and healthcare exposures were evaluated. Predictors of infection were assessed. Of 170 β-lactamase-producing Ent isolates, 85 (50%) were FQS; 23 (27%) had PMFQR genes (PMFQS cases). Eighty-five (50%) were FQR; 53 (62%) had PMFQR genes (PMFQR controls). The median age for children with PMFQS Ent and PMFQR Ent was 4.3 and 6.2 years, respectively (p = NS). Of 23 PMFQS Ent, 56% were Klebsiella spp., and of 53 PMFQR Ent, 76% were E. coli. The most common bla and PMFQR genes detected in PMFQS Ent were bla SHV ESBL (44%) and oqxAB (57%), and the corresponding genes detected in PMFQR Ent were bla CTX-M-1-group ESBL (79%) and aac(6')-Ib-cr (83%). Whole genome sequencing of PMFQS Ent revealed the additional presence of mcr-9, a transferable polymyxin resistance gene, in 47% of isolates, along with multiple plasmids and mobile genetic elements propagating drug resistance. Multivariable regression analysis showed that children with PMFQS Ent infections were more likely to have hospital onset infection (OR 5.7, 95% CI 1.6-22) and isolates containing multiple bla genes (OR 3.8, 95% CI 1.1-14.5). The presence of invasive devices mediated the effects of healthcare setting in the final model. Differences in demographics, comorbidities, or antibiotic use were not found. Paradoxically, PMFQS Ent infections were often hospital onset and PMFQR Ent infections were community onset. PMFQS Ent commonly co-harbored multiple bla and PMFQR genes, and additional silent, yet transferrable antibiotic resistance genes such as mcr-9, affecting therapeutic options and suggesting the need to address infection prevention strategies to control spread. Control of PMFQS Ent infections will require validating community and healthcare-based sources and risk factors associated with acquisition.

A-252 Differentiation of SARS-CoV-2, Influenza A and B, and Respiratory Syncytial Virus Using a Single Swab: A Clinical Performance Evaluation of the BD MAX System Multiplex PCR Assay

Abstract Background Some shared clinical features of SARS-CoV-2, influenza (flu), and respiratory syncytial virus (RSV) infection often pose a diagnostic challenge for clinicians. In that context, the use of molecular diagnostic systems multiplex assays, using a nasopharyngeal or nasal swab, facilitates the detection of the causing virus by differentiating between the RNA of each disease. Our study evaluated the clinical accuracy of one such multiplex PCR assay, the BD Respiratory Viral Panel for BD MAX™ System (BD MAX RVP). Methods Symptomatic patients that had a nasopharyngeal and nasal specimen prospectively collected from 6 geographical locations in the US were enrolled in the study between January and April 2022 along with nasopharyngeal swabs retrospectively collected between December 2019 and January 2022. All specimen testing was performed using the BD MAX System. Hologic® Flu A/B/RSV assay on Panther Fusion™ System was the comparator for flu A, flu B, and RSV while a composite of two out of three assays authorized under FDA Emergency Use Authorization (Roche cobas® SARS-CoV-2 on cobas® 6800 System, Hologic® Aptima® SARS-CoV-2 on Panther® System, and Quidel Lyra® SARS-CoV-2 on Applied Biosystems® 7500 Fast Dx) was used as comparator for SARS-CoV-2. Positive and negative percentage agreements (PPA and NPA, respectively) were calculated to determine performance. Reproducibility and precision assessments were also performed as part of the study. Results Tested specimens included 252 nasopharyngeal and 254 nasal swabs, prospectively collected, and 240 retrospectively acquired nasopharyngeal specimens. For prospectively collected SARS-CoV-2 nasopharyngeal specimens, PPA of 98.8% (95% CI 93.6, 99.8) and NPA of 98.2% (95% CI 94.9, 99.4) were observed while for flu A, PPA was 100% (95% CI 61.0, 100) and NPA 99.6% (95% CI 97.7, 99.9). PPA and NPA for prospectively collected SARS-CoV-2 anterior nasal specimens were 98.8% (95% CI 93.3, 99.8) and 98.3 (95% CI 95.1, 99.4), respectively. For flu A, PPA of 100% (95% CI 61.0, 100) and NPA of 99.6% (95% CI 97.8, 99.9) were observed. Lack of enrolled positive patients with flu B or RSV precluded the PPA calculation for those viruses. However, NPA for both flu B and RSV was 100% for the two specimen types. In retrospectively obtained nasopharyngeal specimens, PPA was 100% (95% CI 93.7, 100) for flu A, 100% (95% CI 93.8, 100) for flu B, and 98.4% (95% CI 91.5, 99.7) for RSV while NPA was 98.9% (95% CI 96.1, 99.7) for flu A, 98.9% (95% CI 96.1, 99.7) for flu B, and 100% (95% CI 97.9, 100) for RSV. Conclusion The BD MAX RVP assay showed a strong clinical performance in detecting and differentiating between the RNA of SARS-CoV-2, flu A and B, and RSV.

A-286 Performance Evaluation of Molecular Clostridium Difficile Assay using BD MaxTM System

Abstract Background Clostridium difficile (C.Diff) is a gram positive anaerobe producing Enterotoxin and Cytotoxin (toxin A and B respectively); toxin B has been reported to be essential for its virulence. It is estimated that C. Diff will cause over half a million infection yearly and one in 11 people over the age of 65 diagnosed with healthcare-associated C.Diff infection die within one month. It is the most common cause of acute diarrhea; residents in Long-Term Care Facilities (LTCF) are more prone to have C. Diff infection (CDI) because of their age, the frequent use of antibiotics, fragilities, co-morbidity, and living environment. Diagnosing CDI is based on clinical signs and symptoms as well as laboratory tests. Several tests available for diagnosing the infection which include: enzyme immunoassays, tissue culture cytotoxicity, anaerobic culture, glutamate dehydrogenase antigen and nucleic acid amplification. The BD MAX™ System is a PCR based assay that provides the sensitivity, specificity and faster turnaround. Methods The MAX™ System is an automated in vitro diagnostic test for the direct qualitative detection of the C. difficile toxin B gene (tcdB) in human liquid or soft stool specimens from patients suspected of having Clostridium difficile Infection (CDI).The test is performed directly on the specimen, utilizing real-time polymerase chain reaction (PCR) for the amplification of C. difficile toxin B gene (tcdB). The test utilizes fluorogenic sequence-specific hybridization probes for detection of the amplified DNA. The test was validated for accuracy, precision, and patient correlation to enzyme-immunoassay using Premier Toxins A & B is an enzyme immunoassay for the direct detection of Clostridium difficile toxin A and toxin B in stool samples. Statistical analyses were done using Analyse-it. Results The percentage agreement for precision, reproducibility, and accuracy were 100%. We had 100% agreement for positive patients on EIA and 85% for negative patients on EIA; however, upon investigation we found the discrepancies were due to false negative EIA results. Conclusion The BD Max gave the benefit of a fully automated with high sensitivity and specificity for the presence of toxin B producing C. Diff. The faster turnaround gives the physician the ability to diagnose CDI and prevent spreading of the disease to other patients. It is very important to remember that C.diff infection can be prevented with appropriate use of antibiotics and implementing antibiotic stewardship and infection control plan to prevent and stop spreading of the infection.

Prospective Evaluation of the BD MAX StaphSR Assay for the Screening of Methicillin-Susceptible and -Resistant Staphylococcus aureus from Nasal Swabs Taken in Intensive Care Unit Patients.

Screening patients for S. aureus nasal carriage has proved effective in preventing cross-contamination and endogenous infection with this bacterium. The aim of this study was to assess the performance of the BD MAX StaphSR assay with liquid Amies elution swabs, taken during routine care of intensive care unit patients. Direct and pre-enriched cultures were used as reference methods to screen for S. aureus and methicillin-resistant S. aureus (MRSA). Discrepant results between the BD MAX StaphSR assay and cultures were resolved by using the Xpert SA Nasal Complete assay. A total of 607 nasal swabs taken from 409 patients were included in this study. Compared to culture methods, the sensitivity and specificity of the BD MAX StaphSR assay were 92.5% and 91.7% for S. aureus screening, and 94.7% and 98.3% for MRSA screening, respectively. In 52 (8.6%) specimens, there was a discrepancy between the results of cultures and the BD MAX StaphSR assay, including 13 (25%) where the results of the BD MAX StaphSR assay were confirmed by the Xpert SA Nasal Complete test. This prospective study showed that the BD MAX StaphSR assay is reliable for S. aureus and MRSA detection from nasal samples taken with liquid Amies elution swabs.

Diagnostic performance of DNA probe-based and PCR-based molecular vaginitis testing.

Using retrospective data from U.S. Food and Drug Administration-approved/cleared molecular vaginal panels, molecular methods were found to have higher detection for Candida vaginitis and lower detection for bacterial vaginitis when compared to probe-based methods. In addition, the differentiation of Candida and non-Candida yeast has not reached the physician community as we observed noncompliance in recommended therapy. Furthermore, the pros and cons of migrating to molecular testing from conventional microscopy for identifying bacterial vaginitis and fungal vaginitis have been examined and reported in this paper. Interestingly, the mean (SD) age for patients with Candida albicans was 40.5 (40.0-41.1) years. Patients with N. glabrata were 5.2-8.1 (mean 6.7) years older than patients with Candida albicans.

Investigation of the Frequency of Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis and Mycoplasma genitalium in Men Living with HIV in Terms of Sociodemographic Characteristics and Behavioral Risk Factors

The aim of this study was to investigate the frequency of Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis and Mycoplasma genitalium in men living with HIV in terms of sociodemographic characteristics and behavioral risk factors. In this cross-sectional, single center study, all HIV-infected male patients, aged ≥ 18 years, including those being followed-up (n= 142) and the new admissions (n= 16) at Hacettepe University, Department of Infectious Diseases between March 1st, 2017 and May 1st, 2018 were included. After obtaining the informed consent form; age, follow-up days in STI-clinic, marital status, education, employment status; STI-related sign and symptoms, prior STI diagnosis, multiple sexual partners during the last year, exchanging sex for money, sexual orientation, drug use, condom use with regular and casual partner and also risk factors regarding partners were inquired as behavioural risk factors. A sample of first-voided urine of each participant was tested for the presence of Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis and Mycoplasma genitalium by using nucleic acid amplification test (NAAT) (BD-MAX system, BD Diagnostics, USA) and BD MAX Mycoplasma-Ureaplasma-OSR for BioGX, (BD Diagnostics, The Netherlands). All participants living with HIV, men who have sex with men (MSM) and heterosexual men were grouped as STI-positive and STI-negative and compared. For all statistical analysis, SPSS 24 software was used. During the period of 14 months; the data was determined as follows: median follow-up time was 1138 (IQR= 159.5- 1494.5) days, median age was 35 (IQR= 28-42) years, 73.3% were single, 68.3% were at least college graduates or had higher educational attainment, 78.1% were currently employed. Of the participants, 26.9% reported STI-related sign and symptoms, 50.0% at least one STI episode in the past. Nine (5.6%) M.genitalium, five (3.1%) N.gonorrhoeae, and four (2.5%) C.trachomatis were detected in the urine samples of 17 (10.7%) individuals. N.gonorrhoeae and C.trachomatis were detected simultaneously in only one patient's urine sample. STI-positive patients (n= 17) were determined to be younger compared to STI-negative group [(p= 0.02; 27 years (IQR= 24-37) vs 35 years (IQR= 28-42)], had prominent STI-related signs and symptoms (p< 0.001) and had more multiple sexual partners (p= 0.03). The median CD4+ T lymphocyte count were relatively lower (p= 0.03) in STI-positive patients and plasma HIV RNA level was higher compared to the STI-negative participants (p= 0.05). STI-positive MSM group were younger [p= 0.01; 26 years (IQR= 23.5-29) vs 33 years, (IQR= 28-40)], STI-related signs and symptoms were more prominent (p= 0.02), the frequency of exchanging sex for money/drugs among their partners (p= 0.03) was higher compared to their STI-negative counterparts. Among STI-positive heterosexual patients, the presence of STI-related signs and symptoms (p= 0.04), drug use among their partners (p= 0.04) and plasma HIV RNA level (p<0.01) were significantly higher. STI was identified as an important health problem in this series of men living with HIV, 63.0% of whom had MSM and had a relatively high education level and socioeconomic status. Young age, having multiple partners, drug use, exchanging sex for money/drugs were prominent among the participants and their partners. Public health studies should focus on preventing STIs in young people living with HIV who have behavioral risk factors.

Novel Software for High-level Virological Testing: Self-Designed Immersive Virtual Reality Training Approach.

To ensure the timely diagnosis of emerging infectious diseases, high-tech molecular biotechnology is often used to detect pathogens and has gradually become the gold standard for virological testing. However, beginners and students are often unable to practice their skills due to the higher costs associated with high-level virological testing, the increasing complexity of the equipment, and the limited number of specimens from patients. Therefore, a new training program is necessary to increase training and reduce the risk of test failure. The aim of the study is to (1) develop and implement a virtual reality (VR) software for simulated and interactive high-level virological testing that can be applied in clinical practice and skills building or training settings and (2) evaluate the VR simulation's effectiveness on reaction, learning, and behavior of the students (trainees). Viral nucleic acid tests on a BD MAX instrument were selected for our VR project because it is a high-tech automatic detection system. There was cooperation between teachers of medical technology and biomedical engineering. Medical technology teachers were responsible for designing the lesson plan, and the biomedical engineering personnel developed the VR software. We designed a novel VR teaching software to simulate cognitive learning via various procedure scenarios and interactive models. The VR software contains 2D VR "cognitive test and learning" lessons and 3D VR "practical skills training" lessons. We evaluated students' learning effectiveness pre- and posttraining and then recorded their behavior patterns when answering questions, performing repeated exercises, and engaging in clinical practice. The results showed that the use of the VR software met participants' needs and enhanced their interest in learning. The average posttraining scores of participants exposed to 2D and 3D VR training were significantly higher than participants who were exposed solely to traditional demonstration teaching (P<.001). Behavioral assessments of students pre- and posttraining showed that students exposed to VR-based training to acquire relevant knowledge of advanced virological testing exhibited significantly improved knowledge of specific items posttraining (P<.01). A higher participant score led to fewer attempts when responding to each item in a matching task. Thus, VR can enhance students' understanding of difficult topics. The VR program designed for this study can reduce the costs associated with virological testing training, thus, increasing their accessibility for students and beginners. It can also reduce the risk of viral infections particularly during disease outbreaks (eg, the COVID-19 pandemic) and also enhance students' learning motivation to strengthen their practical skills.

Performance of two commercial multiplex polymerase chain reaction assays for the etiological diagnosis of sexually transmitted infections among men who have sex with men.

This study aimed to investigate the etiologies of sexually transmitted infections (STIs) among men who have sex with men (MSM) in Taiwan. Two commercial assays, the BD MAX Chlamydia trachomatis (CT), Neisseria gonorrhoeae (GC), and Trichomonas vaginalis (TV) panel and the Allplex™ STI Essential assay (CT, GC, Mycoplasma genitalium [MG], Mycoplasma hominis [MH], Ureaplasma urealyticum [UU], Ureaplasma parvum [UP], and TV) were evaluated. During the first stage, urine and rectal swab samples from 168 patients were evaluated using the BD MAX assay, and the multiplex RT-PCR Allplex™ STI Essential assay was applied only to the patients with positive results on the BD MAX asay (n=49). During the second stage, urine and rectal swab samples from 90 patients were evaluated using the BD MAX assay and the Allplex™ qPCR. The Allplex qPCR identified all CT, missed one and additionally one TV from the positive samples (n=49) by the BD MAX assay in the first stage. At the second stage, both commercial assays showed similar detection rate of CT, NG or CT/NG coinfection (11.1%, 1.1% and 4.4% by the BD MAX assay; 10.0%, 1.1% and 2.2% by the Allplex qPCR). The positivity rates of MG, MH, and UU by the Allplex qPCR were 4.4%, 2.2%, and 12.2%, respectively, for urine samples and 10%, 13.3%, and 22.2%, respectively, for anal swab samples. High rates of STI-associated etiologies were observed in MSM. The positive rates were higher in rectal swabs than in urine samples.

In vitro Activity of Cefiderocol and Ceftazidime-Avibactam, Against Carbapenemase-Producing Enterobacterales

Carbapenemase production is an issue of significant clinical and public health concern, because of the shortage of effective antimicrobial agents available for treatment. Here, we present antimicrobial susceptibility data of ceftazidime-avibactam, cefiderocol, and other clinically relevant antibiotics for carbapenemase-producing Enterobacterales bloodstream isolates, in accordance with European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. A total of 133 carbapenemase producing Enterobacterales bloodstream isolates from May 2010 to September 2018 were included in the study. Species were identified using matrix-assisted laser-desorption ionization time-of-flight mass spectrometry (Bruker Daltonics, Germany). The presence of the blaKPC, blaNDM, blaOXA-48, blaVIM, and blaIMP carbapenemase genes were investigated by BD Max CRE assay (Becton Dickinson, USA) and in-house PCR. Antimicrobial susceptibility testing was performed by the BD Phoenix automated system (Becton Dickinson, USA), except cefiderocol and colistin. Cefiderocol and colistin susceptibility was determined by disk diffusion and broth microdilution method, respectively. Except for cefiderocol and ceftazidime-avibactam, the percentage of susceptible isolates did not exceed 90% for any of the antibiotics tested. Although none of the isolates were resistant to cefiderocol, the ceftazidime-avibactam resistance rate was 9.8%. All of the ceftazidime-avibactam resistant strains were NDM (New Delhi metallo-beta-lactamases) producers. Among the other clinically relevant antibiotics tested, only amikacin, colistin, tigecycline, and fosfomycin susceptibility rates exceeded 50%. Of the 133 isolates 22.6% were resistant to colistin which is the preferred antibiotic with a second active agent for infections caused by metallo-beta-lactamase producing Enterobacterales in Turkey. In our study, resistance to ceftazidime-avibactam was detected only in metallo-beta-lactamase producing Enterobacterales isolates, while cefiderocol was found to be effective against all strains. It is important to monitor regional antimicrobial susceptibility data, as the emergence of antimicrobial resistant phenotypes is directly linked to the use of any given antimicrobial agent.

Evaluation of Diagnostic Performance of Bd Max Ebp Assay in Patients with Diarrheal Illness

Objective: Detection of the etiological agents in patients with acute diarrhea is challenging due to a wide variety of pathogens. The aim of this study is to evaluate the diagnostic performance of BD Max Enteric Bacterial Pathogens (EBP) PCR assay in patients with diarrheal illness. Methods: Between 1 January 2014 and 31 May 2015, stool samples from pediatric or adult patients with diarrhea submitted for routine analysis of bacterial stool pathogens were included in the study. We compared the BD Max EBP PCR assay to culture for the detection of Salmonella spp., Shigella spp., Campylobacter jejuni, and Campylobacter coli and an EIA for Shiga toxins 1 and 2. Discordant results were adjudicated by either antigen detection methods or Film array GI Panel. Results: When coinfections were excluded, the positive percent agreement values for the BD Max EBP assay (PPA) was 100% and negative percent agreement (NPA) was between 98.0%-99.7%, when compared with culture and EIA. After discrepant analysis, the PPA values for the BD Max EBP assay was 100% and NPA was between 99.5%-100%. Conclusion: The BD Max EBP assay showed a high correlation rate with conventional and molecular methods for the detection of stool pathogens.

Feasibility, Ease-of-Use, and Operational Characteristics of World Health Organization–Recommended Moderate-Complexity Automated Nucleic Acid Amplification Tests for the Detection of Tuberculosis and Resistance to Rifampicin and Isoniazid

Four moderate-complexity automated nucleic acid amplification tests for the diagnosis of tuberculosis are reported as having laboratory analytical and clinical performance similar to that of the Cepheid Xpert MTB/RIF assay. These assays are the Abbott RealTime MTB and RealTime MTB RIF/INH Resistance, Becton Dickinson MAX MDR-TB, the Hain Lifescience/Bruker FluoroType MTBDR, and the Roche cobas MTB and MTB RIF/INH assays. The study compared feasibility, ease of use, and operational characteristics of these assays/platforms. Manufacturer input was obtained for technical characteristics. Laboratory operators were requested to complete a questionnaire on the assays' ease of use. A time-in-motion analysis was also undertaken for each platform. For ease-of-use and operational requirements, the BD MAX MDR-TB assay achieved the highest scores (86% and 90%) based on information provided by the user and manufacturer, respectively, followed by the cobas MTB and MTB-RIF/INH assay (68% and 86%), the FluoroType MTBDR assay (67% and 80%), and the Abbott RT-MTB and RT MTB RIF/INH assays (64% and 76%). The time-in-motion analysis revealed that for 94 specimens, the RealTime MTB assay required the longest processing time, followed by the cobas MTB assay and the FluoroType MTBDR assay. The BD MAX MDR-TB assay required 4.6 hours for 22 specimens. These diagnostic assays exhibited different strengths and weaknesses that should be taken into account, in addition to affordability, when considering placement of a new platform.

Evaluation of the Methods Used for the Detection of Entamoeba histolytica in Stool Samples of Patients with Diarrhea

Amoebic dysentery (amebiasis) is a parasitic infection caused by Entamoeba histolytica. The diagnosis of invasive amebiasis has traditionally been based on direct and stained microscopic examination of stool samples. Stool microscopy exhibits low sensitivity and it is difficult to distinguish E.histolytica cysts and trophozoites from cells such as leukocytes, macrophages and non-pathogenic Entamoeba species in the stool by microscopy. Therefore more sensitive and specific diagnostic methods such as enzyme linked immunosorbent assay (ELISA) tests which investigate the presence of E.histolytica-specific antigen in stool, and polymerase chain reaction (PCR) are being widely used. In this study it was aimed to study stool samples of the patients who applied with the clinical signs of amebiasis by using direct and permanent stained microscopy, E.histolytica adhesin antigen ELISA test and real-time PCR-based BD Max Enteric Parasite Panel (BD Max EPP) test and to evaluate the diagnostic values of these tests. A total of 546 faecal samples with blood and/or mucus were analyzed in the study. In these samples, the presence of E.histolytica was investigated by direct and permanent stained microscopy, E.histolytica adhesin antigen ELISA and BD Max EPP PCR. Of the samples 36.3% were suspected to contain E.histolytica/dispar/moshkovskii cyst and/or trophozoite by direct microscopic examination. Trichrome staining was performed on these samples and 49 samples were found suspicious for the presence of E.histolytica/dispar/moshkovskii cysts and/or trophozoites. The presence of E.histolytica and other Entamoeba species was not confirmed in 75.2% of the samples. BD Max EPP PCR and E.histolytica adhesin antigen ELISA tests were studied in 49 faecal samples that were suspected by trichrome staining. None of these samples were positive by ELISA. Forty-four samples were negative by PCR and invalid test results were obtained in five samples. In this study, E.histolytica was not detected in the patient population. The results of this study showed that microscopic examination alone is not sufficient for the detection of E.histolytica. It is concluded that it is necessary to use a more sensitive and specific also rapid diagnostic test such as E.histolytica-specific antigen detection test or PCR in the diagnosis of amebiasis to avoid misdiagnosis and unnecessary treatment of patients.