Lab Matters Summer 2021 | Page 61

APHL 2021 Poster Abstracts

Antibiotic-resistant Staphylococcus epidermidis Isolated from Patients and Healthy Students Comparing with Antibiotic-Resistant Bacteria Isolated from Pasteurized Milk

M . EL-Adli ¹ , N . Al-Harbi ¹ , J . Khaled ¹ , A . Al-Obaidi ¹ , S . Kadaikunnan ¹ , S . Al-Yahya ² ; ¹ King Saud University , Riyadh , Saudi Arabia , ² King Abdulaziz City for Science and Technology , Riyadh , Saudi Arabia

Antibiotic-resistant Staphylococci are a global issue affecting humans , animals , and numerous natural environments . Antibioticresistant Staphylococcus epidermidis is an opportunistic pathogen frequently isolated from patients and healthy individuals . This study aimed to examine the antibiotic resistance of S . epidermidis isolated from patients , healthy students and compare the results with antibiotic-resistant bacteria isolated from pasteurized milk . Clinical strain isolation was performed in several hospitals in Riyadh . Skin swabs from 100 healthy undergraduate candidate students were obtained at King Saud University . The pasteurized milk samples were obtained from local market ( company X ). After isolation , identification and susceptibility tests were performed using an automated system . A multiplex tuf gene-based PCR assay was used to confirm identification . Biofilm production and biofilmrelated gene expression were studied . S . epidermidis represented 17 % of clinical bacterial isolates , and 1.7 % of isolates obtained from healthy students were multiantibiotic-resistant . All patient strains were teicoplanin- and vancomycin-susceptible , while all student strains were gentamicin- , levofloxacin- , moxifloxacin- , and trimethoprim / sulfamethoxazole-susceptible . All the bacteria isolated from pasteurized milk were benzylpenicillin and oxacillin-resistant strains . Of the S . epidermidis strains , 91 % could produce biofilms , and mecA , icaADBR , ica-ADB , ica-AD , ica-A only , and ica-C only were expressed in 83 , 17.1 , 25.7 , 37.1 , 20 , and 0 % of the strains , respectively . This work demonstrates that S . epidermidis can be accurately identified using a multiplex tuf-based assay , and that multiantibiotic-resistant S . epidermidis strains are widespread amongst patients and healthy students .

Presenter : Mohammed El-Adli , King Saud University , meladli @ hotmail . com

Analysis of Drug Residue in Needle-Exchange Syringes in Washington , DC

A . Evans , M . Krause , L . Short , S . Leach , M . Levitas , L . Nguyen , DC Department of Forensic Sciences , Washington , DC

After viewing this poster , attendees will gain insight into geospatial drug trends in Washington , DC , compiled from the analysis of drug residue within used syringes donated by needle-exchange programs . This study represents the first time an analysis of residual contents from used syringes collected from harm reduction services ( needle-exchange programs ) has been conducted in the District of Columbia . As drug abuse remains a complex , dynamic phenomenon , it is hypothesized herein that the supplemental surveillance of needle-exchange syringes can provide more comprehensive opioid monitoring . Since the opioid epidemic was declared a public health emergency in 2017 , increased knowledge of up-to-date opioid abuse , opioid trends , and novel emerging substances has been needed . Public health organizations and harm reduction services require real-time , comprehensive data to allow for the revision and adaptation of intervention and prevention strategies . In cooperation with three local needle-exchange programs , anonymously donated used syringes were collected on a weekly basis . Syringes were collected individually in sharps safety tubes and geotagged with the collection sites location . The analysis of residual content in syringes was accomplished by performing a methanolic extraction prior to filtering , then gas chromatography-mass spectrometry ( GC-MS ). Batches were prepared and run bi-weekly , with time from exchange to analysis estimated between 1 to 7 days . Geospatial analysis was performed using ArcGIS Pro™ , highlighting the prevalence of specific controlled dangerous substances . Preliminary data shows that fentanyl is the most commonly detected controlled substance in all needle-exchange syringes , suggesting a shift in previously observed opioid consumption . We have also tested an unexpected number of syringes containing both cocaine and fentanyl , suggestive of the dangerous drug cocktail known as a “ speed-ball .” For the first time , we have observed methamphetamine and eutylone as both standalone products in syringes and in combination with fentanyl . Also for the first time , we have seen two synthetic cannabinoids in a syringe : MDMB-4en-PINACA and 5-fluoro-EMB-PICA . Lastly , we are monitoring emerging trends in toxic adulterants ( i . e ., xylazine ) that increase the likelihood of an overdose when mixed with other dangerous substances . This data provides new intelligence on intravenous ( IV ) drug-user practices and emerging dangerous substances within the District of Columbia . Such knowledge is invaluable to users , public health officials , medical providers , emergency responders , and law enforcement agencies .

Presenter : Alexandra Evans , DC Department of Forensic Sciences , Alexandra . evans @ dc . gov

Validation of MALDI-TOF for Identification of Mycobacteria in a Public Health Laboratory

R . Fowler , S . LaVoie , M . Rivera , Y . Francis-Morris and J . Rakeman , New York City Public Health Laboratory , New York City , NY

Introduction : Rapid identification ( ID ) of mycobacteria , particularly Mycobacterium tuberculosis complex ( MTBC ), is critical to both public health surveillance and clinical diagnostics . Matrix-assisted laser desorption ionization-time of flight mass spectroscopy ( MALDI- TOF ) has a shorter time to result and lower cost than traditional methods used to ID mycobacteria , such as high-performance liquid chromatography ( HPLC ). This study describes the validation of Bruker Biotyper MALDI-TOF for the ID of mycobacteria and the incorporation of MALDI-TOF into the routine workflow in the public health laboratory .

Methods : The validation study included 200 isolates of MTBC and the most common non-tuberculous mycobacteria ( NTM ) identified at NYC PHL . Isolates were cultured on multiple media types prior to extraction for testing , including Mycobacteria Growth Indicator Tube ( MGIT ) broth , Lowenstein Jensen ( LJ ) slant , and 7H10 agar plate ; at least 50 isolates were extracted from each media type . All mycobacterial isolates were initially identified by the HPLC Sherlock™ Mycobacterial System ( MIDI , Inc .). Inactivation and protein extraction for MALDI-TOF analysis was performed using bead mill tubes with 70 % ethanol , followed by formic acid and acetonitrile extraction . All isolates were spotted in duplicate and reference strains were used to evaluate inter- and intra-assay reproducibility . MALDI-TOF identifications were considered acceptable for any isolate with ID score of > 1.8 .

Results : A total of 215 isolates of MTBC and NTM ( both rapid and slow growing species ) were evaluated by MALDI-TOF . Genus level ID of all mycobacterial isolates as determined by MALDI-TOF was 100 %

Infectious Disease