MicroScan WalkAway Research Articles

Pathogenic Characteristics and Risk Factors for ESKAPE Pathogens Infection in Burn Patients

ObjectiveThis study aimed to determine the clinical manifestations, antimicrobial resistance, molecular characteristics, and risk factors for ESKAPE pathogens infection in burn patients.MethodsA retrospective study of 187 burn patients infected with ESKAPE pathogens was conducted at the Department of Plastic and Burn Surgery of the Affiliated Hospital of Southwest Medical University (Luzhou, China) from October 2018 to June 2021. All strains were identified using a MicroScan WalkAway 96 Plus System, and antimicrobial susceptibilities were determined using the VITEK system or the disk diffusion method. The antimicrobial resistance genes of multi-drug resistant ESKAPE (MDR-ESKAPE) were detected by polymerase chain reaction (PCR). The multivariable logistic regression analysis was used to estimate the risk factors for ESKAPE infection and MDR-ESKAPE infection.ResultsA total of 255 strains were isolated in various types of clinical specimens from 187 burn patients, of which 47.5% were ESKAPE pathogens (121/255). Among these, MDR-ESKAPE pathogens accounted for 55% (67/121). Additionally, aph3ʹIII, mecA, blaSHV, blaTEM, blaPDC, and blaSHV were the most prevalent genes detected in Enterococcus faecalis, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp., respectively. The independent risk factors for ESKAPE infection were total body surface area (TBSA) >30–50% (odds ratio [OR] = 10.428; 95% confidence interval [CI], 2.047 to 53.108), TBSA >50% (OR = 15.534; 95% CI, 1.489 to 162.021), and parenteral nutrition (OR = 3.597; 95% CI, 1.098 to 11.787). No independent risk factors were found for MDR-ESKAPE infection.ConclusionClinical staff should be alert to the risk of nosocomial infection with ESKAPE pathogens in burn patients receiving parenteral nutrition and under TBSA >30%. Full attention should also be paid to the ESKAPE resistance, strict adherence to infection control protocols for the rational use of antimicrobial agents, and enhanced clinical standardization of antimicrobial agents management.

GC-mass determination for the biodegradative products of 2,6-dimethylpyridine using Dead-Sea bacterial isolate

Dead sea soil is known for its hypersaline environment and it is a promising location for isolating extremophilic bacteria with interesting metabolic features. In the current study, we isolated a gram-positive bacterium with the ability to degrade 2,6-dimethyl pyridine (2,6-DMP), also known as 2,6-lutidine, a chemical pollutant. The isolated bacteria were identified using the automated Microscan Walkaway system and the different biochemical reactions were determined. In minimal media using the 2,6-DMP as a sole carbon source, the bacterial isolate showed the ability to convert approximately 40 % of 2,6-DMP within 5 days. The GC-Mass analysis for the degradation products indicated that mono- and dihydroxylation for the pyridine ring and oxidation of one or both of the terminal methyl groups have occurred. Based on this finding, this isolated bacterial can further be utilized for bioremediation purposes.

Comparison of MICs in Escherichia coli isolates from human health surveillance with MICs obtained for the same isolates by broth microdilution.

ObjectivesHuman health surveillance and food safety monitoring systems use different antimicrobial susceptibility testing (AST) methods. In this study, we compared the MICs of Escherichia coli isolates provided by these methods.MethodsE. coli isolates (n = 120) from human urine samples and their MICs were collected from six medical laboratories that used automated AST methods based on bacterial growth kinetic analyses. These isolates were retested using broth microdilution, which is used by the food safety monitoring system. The essential and categorical agreements (EA and CA), very major errors (VME), major errors (ME) and minor errors (mE) for these two methods were calculated for 11 antibiotics using broth microdilution as a reference. For statistical analysis, clinical breakpoints provided by EUCAST were used.ResultsFive study laboratories used VITEK®2 and one MicroScan (Walkaway Combo Panel). Out of 120 isolates, 118 isolates (98.3%) were confirmed as E. coli. The 99 E. coli isolates from five study laboratories that used VITEK®2 showed high proportions of EA and CA with full agreements for gentamicin, meropenem, imipenem and ertapenem. Additionally, 100% CA was also observed in cefepime. Few VME (0.5%), ME (1.9%) and mE (1.5%) were observed across all antibiotics. One VME for ceftazidime (7.1%) and 12 MEs for ampicillin (29.4%), cefotaxime (2.4%), ciprofloxacin (3.2%), tigecycline (1.5%) and trimethoprim (22.2%) were detected.ConclusionsMICs from E. coli isolates produced by VITEK®2 were similar to those determined by broth microdilution. These results will be valuable for comparative analyses of resistance data from human health surveillance and food safety monitoring systems.

Evaluation of the Vitek 2, Phoenix, and MicroScan for Antimicrobial Susceptibility Testing of Stenotrophomonas maltophilia.

Stenotrophomonas maltophilia causes high-mortality infections in immunocompromised hosts with limited therapeutic options. Many U.S. laboratories rely on commercial automated antimicrobial susceptibility tests (cASTs) and use CLSI breakpoints (BPs) for S. maltophilia. However, contemporary data on these systems are lacking. We assessed performance of Vitek 2, MicroScan WalkAway, and Phoenix relative to that of reference broth microdilution for trimethoprim-sulfamethoxazole (SXT), levofloxacin (LEV), minocycline (MIN), and ceftazidime (CAZ) with 109 S. maltophilia bloodstream isolates. Using CLSI breakpoints, categorical agreement (CA) was below 90% on all systems and drugs, with the exception of SXT by MicroScan (98.1%) and Phoenix (98.1%) and MIN by MicroScan (100%) and Phoenix (99.1%). For SXT, Vitek 2 yielded a 77.1% CA. LEV and CAZ CA ranged from 67% to 85%. Very major errors (VME) were >3% for SXT (MicroScan, Phoenix), LEV (MicroScan), and CAZ (all systems). Major errors (ME) were >3% for SXT (Vitek 2), LEV (Phoenix), and CAZ (MicroScan, Phoenix). Minor errors were >10% for CAZ and LEV on all systems. Data were analyzed with EUCAST pharmacokinetic/pharmacodynamic CAZ, LEV, ciprofloxacin (CIP), and tigecycline (TGC) breakpoints when possible. CA was <90% for all. VME were >3% for CAZ (all systems), LEV (MicroScan), and TGC (Vitek 2), and ME were >3% for LEV (MicroScan), CAZ (all systems), ciprofloxacin (Vitek 2 and MicroScan), and TGC (Vitek 2, Phoenix). Minor errors (MI) were >10% for all agents and systems, by EUCAST breakpoints with an intermediate category (LEV, CAZ, CIP). Laboratories should use caution with cASTs for S. maltophilia, as a high rate of errors may be observed.

Nosocomial infectious complications in patients with urological malignancies

The objective of the study was to analyze the taxonomic structure of urinary infection pathogens and determine the susceptibility of ESKAPE group microorganisms (Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterococcus spp.) isolated from cancer patients with nosocomial infections in 2018—2020 to antimicrobials.Materials and methods. 413 (71.9 %) strains of ESKAPE group bacteria from 228 patients were studied. Microorganisms were identified and antibiotic resistance was determined using Vitek-2 System (France) and MicroScan WalkAway (Germany / USA) analyzers.Results and conclusion. All gram-positive microorganisms were highly sensitive to vancomycin and teicoplanin, linezolid, tigecycline, and daptomycin, which can be used in the treatment if clinical indications are seen. Among gram-negative bacteria, the percentage of ESBL producers was 60—70 %, the percentage of carbapenem-resistant bacteria was minimalfor E. coli, rnmpared to the rest - 40—50 %, demonstrating the need to limit the use of carbapenems in the clinic.

Suitability Tests for Bacterial Identification and Antibiotic Sensitivity Tests using Microscan Walkaway on Vitek 2

Culture or bacterial culture is the gold standard for diagnostic examination to detect the presence ofmicroorganisms in the patient’s body. The development of culture technology and culture-based automaticdevices for diagnostic examination are widely researched. At present, there are several types of automaticblood culture instruments in Indonesia, namely Vitek 2 and Microscan Walkaway. This research aims toanalyze the suitability of bacterial identification and test antibiotic sensitivity of Microscan Walkaway devicefrom Beckman Coulter and Vitek 2 device from Biomerieux as a gold standard. The research conductedwas an observational cross-sectional study. Sampling was done consecutively. The study sample consistedof 202 samples obtained from the results of positive isolates, during January-July 2019 at Dr. Soetomohospital. Positive isolates were examined for bacterial identification and antibiotic sensitivity using Vitek2 and Microscan Walkaway. The results were statistically analyzed using SPSS. Examination of bacterialidentification using the Microscan device showed 34.2% of Gram-positive bacteria and 65.8% of Gramnegative bacteria, whereas with Vitek 2, results showed 34.7% of Gram-positive bacteria and 65.3% ofGram-negative bacteria. Both of these instruments showed identification accuracy of 98.56% for Grampositive bacteria and 100% for Gram negative bacteria with Kappa value: 0.814 and p &lt;0.0001. The resultsof the accuracy test for antibiotic sensitivity of multidrug resistance bacteria showed compatibility with pvalue &lt;0,0001. There is very good agreement between Vitek 2 and Microscan Walkaway in the identificationof bacteria and antibiotic sensitivity.

Molecular Diversity of NDM-1, NDM-5, NDM-6, and NDM-7 Variants of New Delhi Metallo-β-Lactamases and Their Impact on Drug Resistance.

The emergence of multidrug-resistant bacteria has become a serious healthcare problem worldwide. In this study, 192 clinical specimens collected from a tertiary hospital in Al Jouf, Saudi Arabia were processed in order to isolate gram-negative bacteria. Bacterial isolation was performed using standard microbiological techniques and the MicroScan WalkAway Plus automated analyzer. Phenotypic methods and PCR were done to characterize bacterial strains, and DNA sequencing was used for the molecular characterization of new Delhi metallo-β-lactamases NDM genes. This study reports the presence of the blaNDM gene in 95 gram-negative bacterial isolates. Among the iso-lates, 71 (74%) carried blaNDM-1 and 24 (25%) carried blaNDM gene variants. Different specimen analyses revealed that the samples from the intensive care unit (ICU) showed the highest percentage (38%) of NDM-1 positive isolates. Molecular identification revealed 87% belonged to the Enterobacteriaceae family. The species profiling showed that 41% of the clinical isolates were Klebsiella pneumoniae, 25.3% of isolates were E. coli, and 9.5% were Enterobacter cloacae. Thirteen percent of the gram-negative isolates, Pseudomonas aeruginosa and Acinetobacter baumannii, belonged to the Pseudomonadaceae family and Gammaproteobacteria family, respectively. The antibiotic sensitivity profile of the 95 isolates revealed that all the isolates harboring the NDM gene showed resistance against ampicillin. Among the NDM-harboring isolates, the highest resistance was found against cefuroxime and co-amoxiclav antibiotics. The isolates were the most sensitive to tigecycline and amikacin. However, the ability of some NDM-harboring gram-negative isolates to grow in the presence of amikacin and tigecycline suggests that these NDM-producing strains carry an additional drug-resistance mechanism. The prevalence of NDM-harboring gram-negative bacterial isolates in hospital settings is an alarming situation. The Enterobacteriaceae family was found to be the most common carrier of the NDM gene, which indicates a need for more stringent use of antibiotics and better control in hospitals to minimize the risk of cross contamination and spread of NDM-positive strains.

Çeşitli Klinik Örneklerden İzole Edilen Vankomisine Direçli Enterokok (VRE) Suşlarının Fenotipik ve Genotipik Değerlendirilmesi

Objective: Enterococci are among the important microorganism group worldwide due to their natural resistance to many antibiotics, especially their acquired resistance mechanisms against glycopeptides (vancomycin, teicoplanin). In this study, vancomycin and teicoplanin resistance were phenotypically determined in Vancomycin-resistant Enterococci strains obtained from various clinical specimens, and the presence of VanA, VanB and VanC was investigated by molecular methods. Method: A total of 30 VRE strains isolated from various clinical specimens at Microbiology Laboratory of Van Yuzuncu Yil University Faculty of Medicine Hospital between 2015 and 2018 were included in the study. MicroScan WalkAway 96 Plus (Beckman Coulter, USA) automated system was used for the identification of strains and determination of antibiotic resistance. Antimicrobial resistance to vancomycin and teicoplanin were also determined by gradient test method. Resistance genes were investigated by in-house PCR method performed in Inonu University Faculty of Medicine, Molecular Diagnostics Laboratory of The Department of Medical Microbiology using appropriate primers. Results: Identification tests revealed 29 strains as Enterococcus faecium and 1 as Enterococcus faecalis. While all strains were resistant to vancomycin and teicoplanin in the automated identification system, three isolates tested by gradient test method were found to be susceptible to these antibiotics. Molecular method of these three strains showed that there were no VanA, VanB and VanC genes. While VanA gene was detected in 27 strains, VanB gene was detected in one strain, and VanC gene was not detected. Resistance detection by gradient test and molecular method were found to be 100% compatible in the identification of vancomycinresistance in enterococci isolates. Conclusion: Gradient test method is reliable in determining glycopeptide resistance of enterococcal isolates in clinical microbiology laboratory.

1267. Comparative activity of omadacycline against extended-spectrum beta-lactamase positive and negative Escherichia coli and Klebsiella pneumoniae strains recovered from urine specimens

BackgroundOmadacycline (OMC) is a novel tetracycline (TET) derivative antibiotic with activity against TET-resistant Enterobacterales. OMC is available in both oral and intravenous formulations and is has been studied as a treatment of uncomplicated urinary tract infection (UTI) and acute pyelonephritis. The purpose of this study was to evaluate OMC activity against extended-spectrum beta-lactamase (ESBL) positive and negative Enterobacterales strains recovered from urine specimens.MethodsUrine samples from patients with suspected UTI were quantitatively plated onto blood agar and MacConkey agar plates in the microbiology lab of Wake Forest Baptist Medical Center. After overnight incubation, colonies were identified to the species level by MALDI-TOF system. Susceptibility testing was performed for isolates of E. coli and K. pneumoniae. OMC and TET susceptibility testing was performed by disk diffusion and gradient strip methodologies. Results were interpreted in accordance with the Clinical and Laboratory Standards Institute (CLSI) or Food and Drug Administration breakpoints. Isolates were tested in triplicate. ESBL screening and susceptibility testing to oral antibiotics commonly prescribed for UTI were performed by the MicroScan WalkAway System. Susceptibility rates and MIC50/90 were calculated and subsets of isolates were analyzed using descriptive statistics.ResultsA total of 204 isolates, including 102 E. coli and 102 K. pneumoniae, were tested. All but 1 isolate (99.5%) exhibited categorical agreement in results generated by the strip (Table 1) and disk (data not shown) methods and this was considered a minor error involving an intermediate result. OMC MIC90 for E. coli and K. pneumoniae were 6 µg/mL and >32 µg/mL, respectively. OMC displayed increased susceptibility rates compared to TET regardless of isolate species or ESBL positivity (Table 2).Table 1. Omadacycline Minimum Inhibitory Concentrations (MICs, µg/mL) Table 2. Susceptibilities of Oral Antibiotics Used to Treat UTI (% S) ConclusionOMC exhibits promising antimicrobial activity against TET-resistant and ESBL-positive E. coli and K. pneumoniae. OMC displays superior activity to ESBL positive E. coli when compared to ESBL positive K. pneumoniae. These data support the development of OMC as a much needed option in the treatment of UTI caused by resistant Enterobacterales.Disclosures Tyler J. Stone, PharmD, Paratek (Research Grant or Support) Abdullah Kilic, MD, Paratek (Grant/Research Support) John Williamson, PharmD, Paratek (Research Grant or Support) Elizabeth Palavecino, MD, Paratek (Grant/Research Support)Paratek (Grant/Research Support)

Loranthus acaciae: Alternative medicine for β-lactamase producer and methicillin-resistant Staphylococcus aureus.

Recently, we reported high antibacterial efficiency of Loranthus acaciae (LA) against different standard strains of bacteria including Methicillin-Resistant Staphylococcus aureus (MRSA). Therefore, this study aimed to confirm the effectiveness of LA against clinically isolated Staphylococcus aureus (SA) including β-lactamase producer (Blac) and MRSA. Forty-eight SA isolates collected from various clinical samples were used in this study. Antibiotics susceptibility profile was determined for twenty different antibiotics using automated Microscan Walkaway 96 Plus system as recommended by Clinical and Laboratory Standards Institute (CLSI) guidelines. This system also identified β-lactamase producers and MRSA. In the meantime, LA ethanolic extract was fractionated using liquid–liquid fraction method to hexane, dichloromethane DCM and methanol 80% fractions. Antimicrobial activities of LA extract and fraction were performed with agar well diffusion method for all SA isolates, MIC and MBC were also recorded. Phytochemical screening for various phyto-constituent classes of LA ethanolic extract was determined. Out of 48 SA isolates, Cefoxitin-positive MRSA represent 31 (64.6%), Blac 17 (35.4%), and 41 (85.4%) were multidrug-resistant SA, which was resistant at least to one antibiotic from three different categories. All isolates were resistant to ampicillin and penicillin. Antimicrobial activities of LA extract and fractions revealed that ethanol extract was active against all isolated SA with inhibition zone ranged from 33 ± 2.00 to 25 ± 3.05 mm. While DCM exhibited the largest inhibition zone range from 37 ± 3.00 to 33 ± 2.00 mm. This study is first of its kind conforming the high antibacterial activity of LA against SA isolated from a different source of infection. The study concluded that LA extract and fractions are active and give positive result for all isolated SA. Therefore, suitable pharmacological formulation of LA extract as a promising antibacterial agent for the treatment of SA infection should be given extreme priority.

Public Health Risk Assessment of the Door Handles of the Community Pharmacies in Qassim Region, Saudi Arabia

Door handles are being reported to harbor a diverse group of microorganisms, mainly bacteria. Presence of pathogenic and antibiotic-resistant bacteria in the door handles carry risk to the health of the public. For this reason, a study was carried in the Qassim region of Saudi Arabia by isolating bacteria from the pharmacy door handles from four different areas. Total 100 samples were collected by wiping the door handles with a sterile cotton swab soaked in sterile water. Microorganisms were isolated using Blood agar and MacConkey agar and identified following standard microbiological procedure. Siemens MicroScan Walkaway system was used for determination of antibiotic susceptibility pattern. In total, 301 bacteria from 13 bacterial species were isolated and identified. The predominant bacterial species include Staphylococcus spp. 56.48% followed by Bacillus spp. 12.29% and Micrococcus spp. 10.30%. Gram-negative bacteria like Shigella sonnei and Salmonella paratyphiA were also isolated. Being the most predominant species, Antibiotic resistance pattern of 39 Staphylococcus spp. were determined. 38.46% of the Staphylococcus spp. were found to be resistant to Cefoxitin, and 30.76% were beta-lactamase producing. The results also indicated that about one -third of Staphylococcus spp. were methicillin resistant. The door handles of pharmacies in the Qassim region carry risk to the health of the public. Proper hygienic measures are recommended for the public health safety until doors are made automatic and touch-free.

A Cluster of Corneal Donor Rim Cultures Positive for Achromobacter Species Associated With Contaminated Eye Solution.

To investigate a cluster of corneoscleral rim cultures positive for Achromobacter species over a 6-month period at Massachusetts Eye and Ear. An increased rate of positive corneal donor rim cultures was noted at Massachusetts Eye and Ear between July and December 2017. Positive cultures were subjected to identification and antimicrobial susceptibility testing by phenotypic (MicroScan WalkAway) and genotypic (16S rDNA sequencing) methods. Samples of the eye wash solution (GeriCare) used in the eye bank were also evaluated. Antimicrobial activity of Optical-GS against Achromobacter spp. at 4°C and 37°C was assessed by time-kill kinetics assay. Of 99 donor rims cultured, 14 (14.1%) grew bacteria with 11 (78.6%) due to uncommon nonfermenting Gram-negative bacilli. These had been identified by standard automated methods as Achromobacter (n = 3), Alcaligenes (n = 3), Ralstonia (n = 2), Pseudomonas (n = 2), and Stenotrophomonas (n = 1). Eight of these 11 isolates were subsequently available for molecular identification, and all were identified as Achromobacter spp. Six bottles of eyewash solution were evaluated and were positive for abundant Achromobacter spp. (3.4 × 105 ± 1.1 CFU/mL). Optisol-GS had no bactericidal activity against Achromobacter spp. at 4°C after 24-hour incubation but was bactericidal at 37°C. None of the patients who had received the contaminated corneas developed postoperative infection. An eyewash solution arising from a single lot was implicated in the contamination of donor rims by Achromobacter spp. The isolates were able to survive in the Optisol-GS medium at the recommended storage temperature. This highlights the need to continue improving protocols for tissue preparation and storage.

Comparative Evaluation of CHROMagar COL-APSE, MicroScan Walkaway, ComASP Colistin, and Colistin MAC Test in Detecting Colistin-resistant Gram-Negative Bacteria

Colistin has become a critical antibiotic for fatal Gram-negative infections owing to the proliferation of multidrug-resistant carbapenemase-producing bacteria. Thus, cheaper, faster, efficient and easier-to-use colistin diagnostics are required for clinical surveillance, diagnoses and therapeutics. The sensitivity, specificity, major error (ME), very major error (VME), categorial agreement, essential agreement, turnaround time (TAT), average cost, and required skill for four colistin resistance diagnostics viz., CHROMagar COL-APSE, ComASP Colistin, MicroScan, and Colistin MAC Test (CMT) were evaluated against broth microdilution (BMD) using 84 Gram-negative bacterial isolates. A multiplex PCR (M-PCR) was used to screen all isolates to detect the presence of the mcr-1 to mcr-5 genes. A 15-point grading scale was used to grade the tests under skill, ease, processing time etc. mcr-1 was detected by both M-PCR and CMT in a single E. coli isolate, with other PCR amplicons suggestive of mcr-2, -3 and -4 genes being also observed on the gel. The sensitivity and specificity of CHROMagar COL-APSE, MicroScan, and ComASP Colistin, were 82.05% and 66.67%, 92.31% and 76.92%, and 100% and 88.89% respectively. The MicroScan was the most expensive at a cost (per sampe tested) of R221.6 ($15.0), followed by CHROMagar COL-APSE (R118.3; $8.0), M-PCR (R75.1; $5.1), CMT (R20.1; $1.4) and ComASP Colistin (R2.64; $0.2). CHROMagar was the easiest to perform, followed by ComASP Colistin, M-PCR, MicroScan, CMT and BMD whilst M-PCR and MicroScan required higher skill. The ComASP Colistin was the best performing diagnostic test, with low VME and ME, making it recommendable for routine colistin sensitivity testing in clinical laboratories; particularly, in poorer settings. It is however limited by a TAT of 18–24 hours.

Molecular Analysis of the Antibiotic Resistant NDM-1 Gene in Clinical Isolates of Enterobacteriaceae

The emergence of the New Dehli metallo-beta-lactamase (NDM) gene in Enterobacteriaceae is responsible for multidrug resistance responsible for severe infections and serious morbidity in patients. Our study aimed to define the molecular characteristics and antibiogram of the NDM-1 producing Enterobacteriaceae. We isolated 370 individual enterobacteria from the clinical specimens collected from the two tertiary hospitals in Sakaka, Saudi Arabia. Bacterial isolation was performed using standard microbiological techniques and the Phoenix and Microscan WalkAway Plus automated analyzers. Bacterial strains were characterized by phenotypic methods and PCR, and DNA sequencing was used for the molecular characterization of NDM genes. The blaNDM gene was detected among the 68 members of the Enterobacteriaceae including a single case of rarely reported Cedecea lapagei. Of these 68, 43 isolates (63.2%) were blaNDM-1 and 25 (36.8%) were blaNDM variants. A statistically significant relationship between the NDM-1 and Klebsiella pneumoniae (p = 0.004) was seen, and the relationship between the NDM variants was significantly associated with Citrobacter freundii (p = 0.02) and Escherichia coli (p = 0.03). The in vitro minimum inhibitory concentrations (MICs) of NDM-producing Enterobacteriaceae revealed a very high rate of antibiotic resistance against several groups of antibiotics. These bacterial strains were less resistant to two aminoglycosides, gentamicin (39; 57.3%) and amikacin (27; 39.7%), and showed minimum resistance to tigecycline (25; 36.8%). The emergence of a large number of NDM-1 enterobacteria in our study identifies a substantial public concern, both within hospitals and the wider community, and leaves us a narrow choice of therapeutic options: the aminoglycosides, co-trimoxazole, and tigecycline.

The Potential Sources of Transmitting of Hospital Acquired Infection by Routine Devices in Adult ICU in Alrass General Hospital

Hospital-acquired infections (HAI) reflect as a major global safety concern for both patients and health-care professionals. These infections could be in the form of cross-infection, endogenous infection and environmental Infection. Over 80% of these infections are related to devices’ utilization needed for patients’ life support. Methods show this is an observational and cross-sectional study, to identify the microorganism and determine the potential source of transmitting of hospital acquired infection by routine devices in adult ICU. The samples were collected using Amies transport media; three swabs were taken from the surfaces of indwelling urinary catheter, mechanical ventilation device and central venous catheter used from every twelve patients. The samples were cultured and analyzed by using microbiologic technique. Finally, all samples analyzed by MicroScan WalkAway 96 pulse. Results showing the most bacteria isolated are “Klebsiella pneumonia” (18.37%), “Acinetobacter baumannii” (11.48%), “Staphylococcus epidermidis” (4.59%), “Staphylococcus haemolyticus” (4.59%), “E. coli” (4.59%), “Serratia marcescens” (2.3%), “Pseudomonas luteola” (2.3%), “Kocurio kristinae” (2.3%) and “Photorhabdus luminscens” (2.3%). This study detects a high contamination of routine devices and resistant organisms. In the end it is recommended that effective infection control practices and effective strategies to control antibiotic-resistant bacteria should be applied.

Genomic analysis of a pan-resistant Klebsiella pneumoniae sequence type 11 identified in Japan in 2016

BackgroundKlebsiella pneumoniae (K. pneumoniae) carbapenemase (KPC)-producing K. pneumoniae has rapidly expanded and is associated with severe nosocomial infections. Last-line antibiotics, such as colistin and tigecycline, remain the only treatment option. This study described the genetic background of a novel pan-resistant KPC-producing K. pneumoniae isolate from Tokyo, Japan. MethodsThe antibiotic susceptibility of clinical isolates from a patient hospitalised in 2016 was tested using a MicroScan WalkAway instrument and the broth microdilution method. Susceptibility was defined according to breakpoints provided by the Clinical and Laboratory Standards Institute. Whole-genome sequencing was performed to detect acquired resistance genes and gene mutations. ResultsThe isolates were identified as part of a laboratory stool and swab surveillance-screening program for infection control. The carbapenem-resistant strain was resistant to β-lactams, including broad-spectrum cephalosporins and carbapenems, and to aminoglycosides, chloramphenicol, fosfomycin, fluoroquinolones, polymyxins, tetracyclines, and trimethoprim/sulfamethoxazole. The K. pneumoniae isolate harboured a plasmid carrying fosA3, rmtB, blaCTX-M-65, blaSHV-12, and blaKPC-2 in a non-Tn4401 mobile element. Colistin resistance was associated with a mutation in the mgrB gene, which regulates PhoP/PhoQ. The K. pneumoniae isolate belongs to sequence type 11, which is a successful epidemic-type strain. ConclusionThis study identified molecular resistance markers in a pan-resistant isolate and provided a genomic description of the pan-resistance and origins of the isolate and plasmid. The isolate is closely related to a recent highly pathogenic carbapenem-resistant K. pneumoniae identified in China; however, it lacks a virulence plasmid (but it could still act as a reservoir for a virulence plasmid). This K. pneumoniae isolate is of concern in hospital and community care settings.

Comparative Evaluation of MicroScan Walkaway 96 Plus ID/AST System and Mikrolatest Broth Microdilution Kit in Assessing In vitro Colistin Susceptibility of Carbapenem-Resistant Clinical Gram-negative Bacterial Isolates: Experience from a Tertiary Care Teaching Hospital in Rishikesh, Uttarakhand

AbstractContext: As reports on colistin resistance are slowly emerging from different parts of the world, it is imperative that the clinical microbiology laboratories should generate accurate in vitro colistin susceptibility results. Aim: The aim is to generate preliminary data on the diagnostic utility of MicroScan WalkAway 96 Plus Identification ID/Antimicrobial susceptibility testing AST system in determining in vitro colistin susceptibility of carbapenem-resistant clinical Gram-negative bacterial isolates. Settings and Design: A pilot study was conducted in a tertiary care teaching hospital located in Rishikesh, Uttarakhand, between May and June 2019. Materials and Methods: Thirty-four carbapenem-resistant Escherichia coli, Pseudomonas aeruginosa and Acinetobacter spp. isolated from various non-repetitive clinical samples during the study period, were subjected to antibiotic susceptibility testing using MicroScan ID/AST system. Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry was used to confirm identity of these isolates. Additional colistin susceptibility testing of all test isolates was performed using Mikrolatest minimum inhibitory concentration antibiotic susceptibility testing kit (reference method), which is based on broth micro dilution (BMD) principle. Statistical Analysis Used: Fisher’s exact test. Results: 11.8% (4/34) of the test isolates (100% [2/2] Acinetobacter junii, 10% [1/10] E. coli and 14.3% [1/7] P. aeruginosa respectively) exhibited in vitro colistin resistance by BMD method. Categorical agreement between MicroScan ID/AST system and Mikrolatest kit w. r. t in vitro colistin susceptibility test results was as follows: 71.4% (Acinetobacter baumannii), 85.7% (P. aeruginosa) and 100% (A. junii, A. johnsonii, E. coli and Klebsiella pneumoniae), respectively. Two major errors (MEs) for A. baumannii and one very ME for P. aeruginosa respectively were observed. Conclusions: Data generated by this study will be of help to the clinicians who are often faced with the dilemma of treating multi drug resistant infections with limited treatment options.

Emerging carbapenem-resistant Aeromonas spp. infections in Cali, Colombia

IntroductionAeromonas species are renowned enteric pathogens with virulence determinants linked to human diseases, such as gastroenteritis, skin, soft-tissue and muscle infections, and septicemia. A recent concern of resistance in this organism has emerged, especially the presence carbapenemases. Herein we describe a case series of emerging carbapenem-resistant Aeromonas species infection in our hospital in Cali, Colombia. Materials and methodsCases from 2012 to 2018 are reported. Clinical data was abstracted from the clinical charts and laboratory information. Phenotypic detection of resistance was identified using the VITEK®2 system (BioMérieux) and broth microdilution MicroScan WalkAway plus System (Beckman Coulter). CARBA NP-test and multiplex qPCR assay was performed in 11 isolates to identify genes encoding carbapenemases (blaKPC, blaVIM, blaIMP and blaNDM). Results21 cases of Aeromonas infection in hospitalized patients with phenotypic resistance to carbapenems were studied. The median age was 50 years, 55% (12/21) were male, and 67% (14/21) were healthcare-associated infections (HAI). Aeromonas hydrophila was the most common species (19/21). Forty-three percent (9/21) of the patients were immunocompromised. The mortality was 33% (7/21), and in patients with bacteremia was 100%. Most patients received empirical treatment with meropenem and failed to this treatment. PCR amplification tests showed negative results for the carbapenemases analyzed. ConclusionEmerging phenotypic carbapenem-resistant infection has been seen in our hospital, most as HAI. High mortality was found, especially in immunocompromised patients and in those who failled empirical treatment with carbapenems. As the main carbapenemases tested were negative, carbapenem-resistant could be attributed to an intrinsic metallo-β-lactamase, CphA encoded by the cphA gene, possible hyperproduction of ampC β-lactamase and/or porins expression.

Comparison of Carbapenem-Resistant Microbial Pathogens in Combat and Non-combat Wounds of Military and Civilian Patients Seen at a Tertiary Military Hospital, Philippines (2013–2017)

Bacterial wound infections are a danger to both military and civilian populations. The nature of injury and infection associated with combat related wounds are important in guiding antibiotic prophylaxis and empiric treatment guidelines. The isolates were screened for drug-resistance by the MicroScan Walkaway Plus System using either the Negative Breakpoint Combo Panel (NBCP) 30 or 34 or Positive Breakpoint Combo Panel (PBPC) 20 or 23. Isolates with a minimum inhibitory concentration (MIC) of ≥8 μg/mL to imipenem and/or meropenem were tested for both carbapenemase production using the CarbaNP test and real-time PCR to determine molecular resistance mechanisms. Plasmid conjugation analysis was performed to define potential for horizontal gene transfer. We characterized 634 bacterial wound isolates collected from September 2013 to December 2017 from patients seen at a Philippine military tertiary hospital presenting with combat or non-combat injuries [354 (military) and 280 (civilians)]. Staphylococcus aureus was the most predominant bacterial species isolated from wounds in both populations (104/634, 16%). A variety of Gram-negative bacterial species comprised 442/634 (70%) of the isolates identified, with the most prevalent shown to be Pseudomonas aeruginosa, Enterobacter cloacae, Klebsiella pneumoniae, Escherichia coli, and Acinetobacter sp. Carbapenemase production was detected in 34/442 (8%) Gram-negative isolates. Testing for molecular resistance mechanisms showed 32/34 (17 military, 15 civilian) wound isolates were blaNDM positive and 2 were blaVIM positive, with the two blaVIM isolates found in the civilian population. Plasmid conjugation of 14 blaNDM and 2 blaVIM positive wound isolates representatives showed 2/16 (13%) produced E. coli J53 transconjugants (E. coli from a civilian; E. cloacae from a military). We describe in this study the wound bacterial and antibiotic resistance profile in the military (combat vs non-combat associated) and civilian population. We observed that, with the exception of Acinetobacter sp., resistance of prevalent Gram-negative bacterial species to imipenem or meropenem were not significantly different between the military and civilian populations. We also presented data on the prevalent bacterial species isolated from both combat and non-combat wounds in a military tertiary care hospital setting as well as the carbapenemase-encoding gene primarily responsible for carbapenem resistance as well as evidence of horizontal transfer via mobile genetic elements. Clinicians may use this information to guide empiric antibiotic coverage for the predominant organisms if wound culture results are not readily available.A prospective, longitudinal evaluation of the wound bacterial profile documenting the changing bacterial flora using higher resolution molecular strategies can provide a more comprehensive understanding of the diversity, composition, and abundance of bacterial composition of the wound microbial community from the time of injury, during the course of evacuation from the field to higher level of care facilities, and up to wound resolution.

Burkholderia cenocepacia bacteremia in the oncology clinic: clinical features and outcomes

Aim of the study: To determine clinical course of Burkholderia cenocepacia bacteremia and outcomes in patients receiving cancer therapy. Materials and methods: We indentified 10 adult patients with culture-verified catheter-related Burkholderia cenocepacia bacteremia. Pathogens were identified with protein mass spectrometry of bacteria cells. Testing for the «Microscan WalkAway 40/96 Plus» (Germany) did antibiotic sensitivity or «VITEK 2» (France). Results: In the majority of cases course of bacteremia was indolent; this fact precluded its rapid identification with standard procedures for diagnosing bloodstream infection. All patients developed fever but we revealed neither leukocytosis nor leucopenia which could be attributed to active infection. However, antibiotic treatment was initiated during the 24 h after the first signs of infection in all cases. In one patient bacteremia was complicated with septic shock. We revealed that Burkholderia cenocepacia was able to form biofilms and persist in implanted venous port systems after treatment and in order to eradicate the pathogen venous catheters had to be removed despite effective antibacterial treatment. Initial treatment was prescribed empirically and further antibacterial treatment was adjusted based on sensitivity testing results in 7 patients. Burkholderia cenocepacia eradication rate was 100% and all patients were cured and were able to continue prescribed cancer therapy afterwards. Conclusion: given to the low frequency of Burkholderia cenocepacia sporadic infections, clinicians must be aware of the possibility of drugs and medical supplies contamination with this pathogen. If one reveals ≥1 case of Burkholderia cenocepacia-associated infection the internal investigation must be initiated. Empiric antimicrobial therapy widely prescribed to treat febrile neutropenia in cancer patients is effective in these cases. However, it cannot eradicate the pathogen from inner lumen of implanted venous catheters. Identification of the possible pathogen in blood cultures and antibiotics sensitivity testing using microbiological analyzers prompts the diagnosis of bacteremia and prescription of most effective therapy