Accuracy of Detecting Resistance to Carbapenems among Gram Negative Rods: Comparison of Three Methods

AbstractObjectiveTo compare the results of imipenem and meropenem susceptibility testing among multi-drug resistant (MDR) isolates of Acinetobacter spp., Pseaudomonas aeruginosa (P.aeruginosa) and members of the Enterobacteriacae.MethodsThree methods used for susceptibility testing of 210 isolates: disk diffusion (a reference method), MicroScan (MicroScan Walk Away 96 System, Dade Behring Inc. West Sacramento CA 95691, USA) and Etest (AB Biodisk Solna, Sweden).ResultsOf the 210 isolates, Acinetobacter spp. accounted for the majority of isolates [110(52.4%)] followed by P.aeruginosa, 79 (37.6%). These isolates were more prevalent from respiratory specimens 98 (46.7%), Acinetobacter spp. 60(28.6%) and P.aeruginosa 34(16.2%). The study has demonstrated discrepant results for carbapenems tested by MicroScan and Etest. For imipenem, the MicroScan exhibited 2.8 % very major error, major error was 10.1% but 3.9% by Etest for Acinetobacter spp., Other discrepant results (minor errors) were 28.7% and 33% for MicroScan and Etest, respectively. For meropenem, minor errors were higher by MicroScan (13.6%) and Etest (21%). For P.aeruginosa, very major error (1.6%) was exhibited by imipenem Etest but major errors were 23% and 30.5% for both drugs by MicroScan, respectively. Minor errors were higher for both drugs by both methods (MicroScan: 15.3% to 20.8% and Etest : 34.9% to 34.2%).ConclusionMicrobiology laboratories should consider the use of an additional confirmatory test for carbapenem susceptibility testing of clinical isolates of Acinetobacter spp. and P.aeruginosa and members of the Enterobacteriacae

Prevalence and Antibiotic Susceptibility among Gram Negative Bacteria Isolated from Intensive Care Units at a Tertiary Care Hospital in Riyadh, Saudi Arabia

Antibiotic resistance is an essential issue mostly in the intensive care units (ICUs). The Goal of this study was to investigate the widespread of multidrug resistance (MDR) gram-negative bacterial pathogens isolated from ICUs at King Khalid University Hospital (KKUH), Riyadh, KSA, and their ability to produce ESBL and MBL enzymes. All organisms were isolated from different ICUs at (KKUH) between June to December 2016. Identification and antimicrobial susceptibility were committed according to the laboratory policy. The bacterial Isolates flagged as ESBL or MBL by Vitek 2 were confirmed using E-test method recommended by CLSI. 70 isolates from different body sites comprising 25 (35.7 %) were P. aeruginosa, 23 (32.9 % ) were K. pneumoniae, 16 (22.9%) were E. coli, and 6 (8.6 %) were A. baumannii. Among the 23 isolates K. pneumonia and 16 of E. coli, 19 (82.6%) and 16 (100%) were detected as ESBL (+) by double-disk diffusion method according to guidelines of CLSI. On the contrary, ESBL was not detected in any isolates of P. aeruginosa or in A. baumannii. All P. aeruginosa and A. baumannii isolates were carbapenem resistant. MBL was found in all P. aeruginosa, A. baumannii and 4 (17.4 %) of K. pneumonia where E. coli strains did not appear any MBL action. The essential resistance mechanisms in the evaluated strains were ESBL and MBL. Molecular testing is recommended to confirm the phenotypic results and to detect the resistant genes

Performance of the BD ProbeTec ET direct detection assay for the analysis of Mycobacterium tuberculosis in respiratory and non-respiratory clinical specimens

AbstractObjectivesEarly detection of Mycobacterial tuberculosis infection (MTB) is pivotal for the treatment of tuberculosis (TB).BackgroundThis study was performed to evaluate the performance of BD ProbeTec ET direct detection assay (DTB) against the gold standard culture technique for confirmation of MTB infection.Patients and methodsA total of 266 consecutive and non-duplicate clinical specimens for detection of MTB were included in this study. There were 118 respiratory and 148 non-respiratory samples. All samples were tested by microscopy for acid-fast bacillus (AFB), MTB culture and biochemical identification with simultaneous testing by DTB.ResultsA total of 88 samples (33%) were culture-positive for MTB including 39/118 respiratory, 29/99 fluid and 20/49 tissue samples. DTB sensitivity for respiratory samples was 97% and specificity was 96% with a positive predictive value (PPV) of 93% and negative predictive value (NPV) of 99%. Sensitivity of DTB in fluid samples was 80%, specificity 88%, PPV 69% and NPV 93% whereas sensitivity of DTB for tissue samples was 25%, specificity 90%, PPV 63% and NPV 63%. Of the 50 (56.8%) smear-positive samples, DTB sensitivity was 100% for respiratory, 85% for fluid and 100% for tissue samples.ConclusionDTB performed within acceptable limits for the rapid detection of MTB in respiratory samples compared to fluid and tissue specimens

Performance of the BD ProbeTec ET direct detection assay for the analysis of Mycobacterium tuberculosis in respiratory and non-respiratory clinical specimens

Objectives: Early detection of Mycobacterial tuberculosis infection (MTB) is pivotal for the treatment of tuberculosis (TB). Background: This study was performed to evaluate the performance of BD ProbeTec ET direct detection assay (DTB) against the gold standard culture technique for confirmation of MTB infection. Methods: A total of 266 consecutive and non-duplicate clinical specimens for detection of MTB were included in this study. There were 118 respiratory and 148 non-respiratory samples. All samples were tested by microscopy for acid-fast bacillus (AFB), MTB culture and biochemical identification with simultaneous testing by DTB. Results: A total of 88 samples (33%) were culture-positive for MTB including 39/118 respiratory, 29/99 fluid and 20/49 tissue samples. DTB sensitivity for respiratory samples was 97% and specificity was 96% with a positive predictive value (PPV) of 93% and negative predictive value (NPV) of 99%. Sensitivity of DTB in fluid samples was 80%, specificity 88%, PPV 69% and NPV 93% whereas sensitivity of DTB for tissue samples was 25%, specificity 90%, PPV 63% and NPV 63%. Of the 50 (56.8%) smear-positive samples, DTB sensitivity was 100% for respiratory, 85% for fluid and 100% for tissue samples. Conclusion: DTB performed within acceptable limits for the rapid detection of MTB in respiratory samples compared to fluid and tissue specimens

The psychological impact of COVID-19 pandemic on health care workers in a MERS-CoV endemic country

BACKGROUND The global pandemic of coronavirus disease of 2019 (COVID-19) has led to unprecedented psychological stress on health workers (HCWs). We aimed to assess the psychological impact of COVID-19 on HCWs in comparison to the stress brought on by the Middle East respiratory syndrome coronavirus (MERS-CoV) epidemic in Saudi Arabia. METHOD Between February 5th and 16th, 2020, 811 health-care workers (HCWs) of a tertiary care teaching hospital were invited to fill a questionnaire regarding concerns and worries about the novel coronavirus pandemic, along with Generalized Anxiety Disorder (GAD-7) Anxiety Severity screening tool. RESULTS Out of 582 HCWs who completed the survey questionnaire (response rate of 71.8%), about 40% were exposed previously to MERS-CoV infected or suspected patients during a previous hospital outbreak. While there were no COVID-19 cases reported yet in Saudi Arabia at the time of data collection, still, the anxiety level from COVID-19 was significantly higher than that from MERS-CoV or seasonal influenza: 41.1% were more worried about COVID-19, 41.4% were similarly worried about both MERS-CoV and COVID-19, and 17.5% were more stressed by the previous MERS-CoV hospital outbreak. The most frequent concern was transmitting the infection to family and friends (2.71/5) than to themselves only (2.57/5). CONCLUSION Pandemic and epidemic infectious diseases such as COVID-19 or MERS-CoV impose a significant level of anxiety and stress on healthcare workers who are caring of infected patients, with their main concern being the risk of transmitting the infection to their families or to acquire it themselves. Therefore, optimizing the compliance of healthcare workers with the proper infection prevention and control measures is paramount during the infectious disease outbreak, to ensure their safety, to decrease the likelihood of getting infected or transmitting the infection to others, and consequently to alleviate their psychological stress and anxiety