Microbiology Laboratory Research Articles

The foundation for the microbiology laboratory's essential role in diagnostic stewardship: an ASM Laboratory Practices Subcommittee report.

Diagnostic stewardship (DxS) has gained traction in recent years as a cross-disciplinary method to improve the quality of patient care while appropriately managing resources within the healthcare system. Clinical microbiology laboratorians have been highly engaged in DxS efforts to guide best practices with conventional microbiology tests and more recently with molecular infectious disease diagnostics. Laboratories can experience resistance to their role in DxS, especially when the clinical benefits, motivations for interventions, and underlying regulatory requirements are not clearly conveyed to stakeholders. Clinical laboratories must not only ensure ethical practices but also meet obligatory requirements to steward tests responsibly. In this review, we aim to support clinical microbiology laboratorians by providing the background and resources that demonstrate the laboratory's essential role in DxS. The heart of this review is to collate regulatory and accreditation requirements that, in essence, mandate DxS practices as a long-standing, core element of high-quality laboratory testing to deliver the best possible patient care. While examples of the clinical impact of DxS are plentiful in the literature, here, we focus on the operational and regulatory justification for the laboratory's role in stewardship activities.

Uropathogenic Bacterial Detection and Surveillance of Antimicrobial Resistance Pattern in Urine Specimens Referred to Al anbar Province

For clinicians treating patients, antimicrobial resistance is becoming a significant concern. This brief study was therefore conducted to find out how common it is for bacterial isolates that are resistant to multiple drugs (MDR), XDR, and PDR, as well as extensively drug-resistant (XDR), in Anbar hospital. The microbiology department cultivated the clinical samples and identified the bacterial strains. The detection of MDR, XDR, and PDR microorganisms was accomplished by analyzing the antibiotic susceptibility profile of various bacterial isolates. 257 children and adult patients from both sexes were included in this study. The total number of urine samples that gave positive bacterial culture results were 114 (44.4%) and the number of samples that gave negative results was 143(55.6%) . The antibiotic susceptibility profile of 114 bacterial strains was studied. 90(78.9) of gram-negative bacteria strains were MDR, (8.9%) (72.2%) XDR, and (18.9%) PDR was isolated. 24 (21.1%) Gram positive bacterial egative bacteria strains were MDR, (33.3%) (54.2%) XDR, and (12.5%) PDR was isolated. To effectively combat the threat of antibiotic resistance, all clinical microbiology laboratories need to closely monitor MDR, XDR, and PDR.

Uropathogenic Bacterial Detection and Surveillance of Antimicrobial Resistance Pattern in Urine Specimens Referred to Al anbar Province

For clinicians treating patients, antimicrobial resistance is becoming a significant concern. This brief study was therefore conducted to find out how common it is for bacterial isolates that are resistant to multiple drugs (MDR), XDR, and PDR, as well as extensively drug-resistant (XDR), in Anbar hospital. The microbiology department cultivated the clinical samples and identified the bacterial strains. The detection of MDR, XDR, and PDR microorganisms was accomplished by analyzing the antibiotic susceptibility profile of various bacterial isolates. 257 children and adult patients from both sexes were included in this study. The total number of urine samples that gave positive bacterial culture results were 114 (44.4%) and the number of samples that gave negative results was 143(55.6%) . The antibiotic susceptibility profile of 114 bacterial strains was studied. 90(78.9) of gram negative bacteria strains were MDR, (8.9%) ,(72.2%) XDR, and (18.9%)PDR was isolated. 24 (21.1%)Gram positive bacterial egative bacteria strains were MDR, (33.3%) ,(54.2%) XDR, and (12.5%) PDR was isolated. To effectively combat the threat of antibiotic resistance, all clinical microbiology laboratories need to closely monitor MDR, XDR, and PDR.

Microbial Diversity and Antimicrobial Susceptibility from Wound Dehiscence Isolates in an Indonesian Tertiary Referral Hospital

Healthcare-associated infections (HAIs) remain a critical issue for public health in Indonesia, with wound dehiscence associated with surgical site infections (SSIs) being one of them. Globally, SSIs are known as the most common postoperative complications with a heightened prevalence, particularly in low to middle-income countries. With its retrospective and descriptive design, this study aimed to illustrate the microbial patterns identified in Prof. Dr. I.G.N.G. Ngoerah General Hospital from 12 January 2020 to 12 December 2022. The study includes all patients who underwent surgery and were subsequently diagnosed with wound dehiscence and SSIs. Specimens were collected from patients and submitted to the Microbiology Laboratory at the hospital above. Bacterial identification and susceptibility testing to antimicrobials were performed using the Vitek 2 Compact System (bioMerieux, Marcy l'Etoile, France). Patient information was sourced from medical records. Out of 172 samples, 151 (87.8%) yielded positive cultures. Among these, 151 (87.8%) were found to be positive. Gram-negative bacteria were found to be most prevalent, with Escherichia coli (20.2%) and Pseudomonas aeruginosa (19.6%) being the most frequently isolated bacteria. The bacteria isolated were mostly susceptible to amikacin (72.1%), followed closely by meropenem (71.4%). This information could contribute to the development of an empirical antibiotic therapy protocol for wound dehiscence or SSI cases in this local context.

Antibiotic susceptibility of Pseudomonas aeruginosa in Saudi Arabia: a national antimicrobial resistance surveillance study.

Pseudomonas aeruginosa is a common pathogen causing healthcare-associated infections. Most surveillance studies from Saudi Arabia that assessed the resistance by P. aeruginosa were conducted in single centers or did not use broth microdilution (BMD), the gold standard test. This is the first national multicenter study to assess the resistance profiles of P. aeruginosa isolates in Saudi Arabia using BMD. Between 2022 and 2023, isolates from various infection sites were collected from seven hospitals in seven different regions of Saudi Arabia. The isolates were shipped to an academic microbiology lab, where their susceptibility was tested by BMD following Clinical Laboratory Standards Institute guidelines using Sensititre GNX3F plates. %Susceptibility to each antibiotic, and MIC50 and MIC90 were determined. In total, 185 P. aeruginosa isolates were collected. Most isolates came from respiratory specimens (34.1%), followed by urine (21.1%) and skin/soft tissue (17.8%). The highest susceptibility was to amikacin (76.8%). Concurrently, susceptibility to meropenem was 52%, but it was 43.8% to colistin. While all P. aeruginosa isolates met the definition of multidrug-resistance, 41 (22.2%) were difficult-to-treat and 10 (5.4%) were pandrug-resistant. Difficult-to-treat isolates made up 30.3% of skin and soft tissue isolates, 25.4% of respiratory isolates, 21.7% of blood isolates, and 17.9% of urine isolates. Pseudomonas aeruginosa demonstrated an unexpectedly high level of resistance to several commonly used antibiotics. Therefore, antimicrobial stewardship and infection control policies should be strictly enforced by hospitals across the country to optimize treatment, prevent the emergence and spread of resistant strains, and track resistance trends with local antibiograms.

The power of natural products against bacteria causing acne.

To determine the inhibitory effect of lemon, green tea and Shea butter on the bacteria isolated from patients with acne. This Experimental study was conducted at the Microbiology laboratory of the Department of Veterinary Medicine, Kerbala University, Iraq. From February-March/2022. Simple random sampling was used to collect the samples. The culture media was incubated aerobically for 24 hours at 37°C. Lemon, green tea and Shea butter was used to test antimicrobial activity against the isolated bacteria. Antibiotics disks of tetracyclin, methicillin, azithromycin and clarithromycin were used to compare the effect of natural products. Data was analysed using SPSS. There were 50 subjects (35 males and 15 females) included, with mean age 21±3 years (range: 19-24 years). Among the 50 swabs, 26(52%) different microorganisms were isolated. All the isolates show 100% sensitivity against lemon, and 83.3% against green tea, while all the isolates were resistant to Shea butter. The sensitivity of isolates towards the antibiotics used ranged 16.6-83.3%. While lemon and green tea could play a crucial role against different types of bacteria that caused acne, Shea butter had no role to play in this regard.

Optimization of Bioremediation of Crude Oil Polluted Soil through Variation in Moisture Content and Proportion of Augmenting Bacterium and Fungus

Aim: The aim of this study was to enhance bioremediation of crude-oil polluted soil through optimization procedures. Study Design: The Box-Benkhen coded values format and experimental design were used in the design of the study. Place and Duration of Study: The study was carried out in the Microbiology laboratory of the Department of Microbiology, Rivers State University, Nigeria, between February 2024 and July 2024. Methodology: Hydrocarbon utilizing bacteria (HUB) & fungi (HUF) were isolated from crude-oil polluted soil, and screened for hydrocarbon degrading ability (HCDA). HUB and HUF with the highest HCDA were identified and used for bioremediation optimization experiment. In the experiment, different combination of moisture content (MC), and proportion of HUB (pHUB) & HUF (pHUF) were investigated for their effect on extent of hydrocarbon reduction (EoHR). EoHR obtained from the different combinations were fitted using a generalized polynomial model so as to obtain a polynomial equation for predicting EoHR. The equation was used in generating prediction profiles from which the combined values of the 3 parameters that will lead to the highest EoHR was determined. The predicted combined values were implemented in a new setup. A control and a setup enhanced with fertilizer were also prepared. The setups were maintained for 3 weeks. On day 0, 14, and 21 samples were collected and analyzed for total hydrocarbon concentration (THC). Results: The results obtained showed that among the coded isolated HUB and HUF, HB5 and HF1 had the highest HCDA; 36.4% and 4.1% respectively, and were identified phenotypically as Klebsiella ornithinolytica and Aspergillus flavus respectively. The results of the optimization experiment and prediction profiles showed that the highest (68.6%) EoHR was achievable at MC = 20%, pHUB = 10%, and pHUF = 1%. The actual EoHR on day 21 in the optimized, enhanced optimized, and control setups were 60.3, 58.9, and 39.9% respectively. Conclusion: Bioremediation optimization studies is advantageous and should be carried out on crude-oil polluted sites before carrying out bioremediation.

EVALUATION OF MINIMAL INHIBITORY CONCENTRATIONS OF CEFTAROLINE, TEICOPLANIN AND DAPTOMYCIN FOR TREATMENT OF METHICILLIN RESISTANT STAPHYLOCOCCUS AUREUS IN A TERTIARY CARE SETTING

Objective: To evaluate Minimal Inhibitory Concentrations of ceftaroline, teicoplanin & daptomycin for treatment of methicillinresistant Staphylococcus aureus in a tertiary care setting.Study Design: Experimental study.Place and Duration of Study: Department of Pathology, Microbiology Laboratory from Nov 2021 to Oct 2022.Methodology: All the isolated Staph. aureus was processed and identified by colony morphology on blood agar, gram stain,and biochemical tests i.e., catalase, coagulase and DNAase test. Minimal Inhibitory Concentration was evaluated using Estrips for ceftaroline, teicoplanin & daptomycin for all the MRSA strains during the study period.Results: A total of 924 S.aureus strains were processed, and 270 (29.22%) MRSA were recovered during the study period. Thehighest percentage 50 was observed in sputum (n=2), followed by 41.66% in endobronchial washing (n=10), pus 160 (31.25%),tissue 30 (31.25%), pus swab 50 (29.76%), high vaginal swab 2 (25%), and least in blood 16 (14.54%). MICs for all the MRSAisolates to teicoplanin were in susceptible range (≤8µg/ml). MIC of 22 (8.14%) and 14 (5.18%) MRSA isolates for Ceftarolineand daptomycin were in susceptible dose-dependent (SDD=2-4µg/ml) range.Conclusion: The diagnostic modality, antimicrobial susceptibility testing, and MIC determination were found to be the bestapproach for adequate management of MRSA.

Simulation to optimize the laboratory diagnosis of bacteremia.

Optimization of laboratory pathways and resource availability has a direct impact on the clinical management of patients with bloodstream infection. This research offers an insight into the laboratory processing of blood cultures at a system level and allows clinical microbiology laboratories to explore the impact of changes to processes and resources.

Bacterial Culture Results and Antibiograms in Chronic Rhinosinusitis Patients in Mekong Delta, Vietnam

Background The inappropriate use of antibiotics for chronic rhinosinusitis, exceeding established guidelines, is a growing concern in Vietnam. This practice is contributing to the emergence and spread of antibiotic-resistant bacteria. Objective This study aimed to evaluate the results of culture and antibiogram of bacteria on patients in the Mekong Delta, Vietnam, who were treated for chronic rhinosinusitis in 2022-2023. Methods It is a cross-sectional study, including 113 patients who came for treatment with a diagnosis of chronic rhinosinusitis at Can Tho University of Medicine and Pharmacy Hospital, Mekong Delta, Vietnam, from 2022-2023. The bacterial cultures were identified, and their antibiograms were performed in the Microbiology laboratory of Can Tho University of Medicine and Pharmacy. Statistical analysis was performed with SPSS version 20.0. Results The rate of bacterial growth was 97.35%. The cultured bacterial composition had 8 genera, 22 species, and 116 samples, of which 2 bacterial species were cultured, accounting for 5.45%. Antibiogram showed that Streptococcus pneumonia was resistant to cefaclor (83.33%), cefuroxime (100%), trimethoprim+ sulfamethoxazole (100%), and susceptible to chloramphenicol (100%) and vancomycin (100%). Streptococcus haemolyticus was resistant to amoxicillin+clavulanic acid (85.71%) and ampicillin (100%) and susceptible to linezolid (100%) and rifampin (100%). Streptococcus epidermidis was resistant to amoxicillin+clavulanic acid (82.35%), ampicillin (100%), penicillin (100%) and susceptible to linezolid (91.18%) and rifampin (88.24%). Streptococcus aureus was resistant to amoxicillin+clavulanic acid (95%) and ampicillin+sulbactam (90%), and susceptible to linezolid (90%) and synercid (95%). Pseudomonas aeruginosa was resistant to amikacin (100%), meropenem (100%) and tobramycin (90%). Conclusion This study offers some useful information to doctors in the Mekong Delta and across Vietnam. It can be used as a good orientation in choosing the most appropriate antibiotics for treating patients with chronic rhinosinusitis. It is important to be conscious of the current trend of the bacteriological profiles and to regulate the antibiotic treatment regime to improve the effectiveness and reduce antibiotic resistance rate.

Impact of ESKAPE Pathogens on Bacteremia: A Three-Year Surveillance Study at a Major Hospital in Southern Italy.

ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) pose a serious public health threat as they are resistant to multiple antimicrobial agents. Bloodstream infections (BSIs) caused by ESKAPE bacteria have high mortality rates due to the limited availability of effective antimicrobials. This study aimed to evaluate the prevalence and susceptibility of ESKAPE pathogens causing BSIs over three years in a large tertiary hospital in Salerno. Conducted at the Clinical Microbiology Laboratory of San Giovanni di Dio e ''Ruggi D'Aragona'' Hospital from January 2020 to December 2022, blood culture samples from different departments were incubated in the BD BACTEC™ system for 5 days. Species identification was performed using MALDI-TOF MS, and antimicrobial resistance patterns were determined by the VITEK2 system. Out of 3197 species isolated from positive blood cultures, 38.7% were ESKAPE bacteria. Of these, 59.9% were found in blood culture samples taken from men, and the most affected age group was those aged >60 years. (70.6%). Staphylococcus aureus was the main BSI pathogen (26.3%), followed by Klebsiella pneumoniae (15.8%). Significant resistance rates were found, including 35% of Staphylococcus aureus being resistant to oxacillin and over 90% of Acinetobacter baumannii being resistant to carbapenems. These results highlight the urgent need for antimicrobial stewardship programs to prevent incurable infections.

Effectiveness of selective antibiotics use in ESBL-related UTIs

BackgroundUrinary tract infections (UTIs) are the second most common infection, affecting 150 million people each year worldwide. Enterobacteriaceae species expressing extended-spectrum β-lactamases (ESBLs) are on the rise across the globe and are becoming a severe problem in the therapeutic management of clinical cases of urinary tract infection. Knowledge of the prevalence and antibiogram profile of such isolates is essential to develop an appropriate treatment methodology. This study aimed to investigate the prevalence of Enterobacteriaceae isolates exhibiting ESBL and their selective oral antibiogram profile at the district general hospital, Polonnaruwa.ResultsA total of 4386 urine specimens received to the Microbiology Laboratory during the study period. Among them, 1081 (24.6%) showed positive results for urine culture while 200/1081 specimens showed ESBL isolates. Out of the selected 200 specimen’s majority (67.5%) of samples received from the In-Patient Department. There were 200 patients and reported that 115 (57.5%) were females and 85 (42.5%) were males. The majority (51%) of the patients belong to the age group of 55–74 years. Among the ESBLs positive specimens, the majority 74.5% (n = 149) identified organisms were E. coli followed by Klebsiella spp.17.5% (n = 35), Enterobacteriaceae 7% (n = 14) and only1% (n = 2) isolate of Proteus spp. Mecillinam (87.92%) and Nitrofurantoin (83.2%) showed higher effectiveness against E. coli. Nitrofurantoin showed the highest effectiveness against Klebsiella spp. (40%), other Enterobacteriaceae spp. (100%). Proteus spp. showed 100% effectiveness and resistance respectively against Ciprofloxacin, Cotrimoxazole and Nitrofurantoin.ConclusionThe most predominant ESBLs producing uro-pathogen was the E. coli in the study setting and E. coli had higher sensitivity rate against Mecillinam. Among currently used oral antibiotics Nitrofurantoin was the best choice for UTIs caused by ESBL producers.

ANTIBIOGRAM ASSAY OF E.COLI ISOLATES IN PATIENTS WITH URINARY TRACT INFECTION

Screening of prevalent bacterial pathogens for antibiotic susceptibility profiles in different regions is necessary. E. coli and other pathogens are so common in our environment that it is essential to monitor trends in antibiotic susceptibility regularly. Objective: The aim of the study was to find out the antibiotic susceptibility pattern of E.coli isolates in patients with urinary tract infection. Methods: This study was conducted at the Saidu Group of Teaching Hospital Swat after taking permission from the ethical committee of the institute. We collected a total of 900 urine samples from males and females of all ages for culture and sensitivity. The Kirby-Bauer disc diffusion method was used to assess the antibiogram on Mueller-Hinton agar. The plates were kept in incubator at 37°C for the 48 hours, and the inhibition zone was measured. The antibiogram was performed by Kirby-Bauer disc diffusion method applying various antibiotics. The bacterial strains were classified in to three majors groups on the basis of antibiotic susceptibility pattern resistant (R) sensitive (S), and intermediate (I). Data was statistically analyzed presented in the tables and figures. Results: For culture and sensitivity testing, a total of 900 urine samples from patients with suspected UTIs were obtained from the several departments' inpatient and outpatient to the microbiological lab. Substantial bacteriuria was noted in 250 (27.7%). The most prevalent bacteria isolated was E.coli (55%) and its antibiogram was carried out. Ampicillin had the highest proportion of resistance (96.1%), followed by Ceftriaxone (91%), Moxifloxacin (87.1%), and Ceftazidime (75.5%). Whereas it was sensitive to Fosfomycin (94.2%), followed by Sulzone ( 84.3%), Imepinem (84.3%) and Amikacin (78%). Conclusion: It was concluded from the current study that the most prevalent bacteria causing urinary tract infection was E.coli, and this bacteria showed remarkable resistance against Ampicillin Ceftriaxone, Moxifloxacin, and Ceftazidime. The most used bacterium antibiotics for therapy were Fosfomycin, Imepinem and Amikacin. Therefore, antibiotic susceptibility should be considered before therapy.

Evolving strategies in microbe identification—a comprehensive review of biochemical, MALDI-TOF MS and molecular testing methods

Abstract Detection and identification of microorganisms are the first steps to guide susceptibility testing and enable clinicians to confirm diseases and guide therapy. The faster the pathogen identification is determined, the quicker the appropriate treatment can be started. In the clinical microbiology laboratory, multiple methodologies can be used to identify organisms, such as traditional biochemical testing or more recent methods like MALDI TOF MS and nucleic acid detection/identification assays. Each of these techniques has advantages and limitations, and clinical laboratories need to determine which methodology is best suited to their particular setting in terms of clinical needs, availability of technical expertise and cost. This article presents a concise review of the history, utilization, advantages and limitations of the main methods used for identifying microorganisms in microbiology laboratories.

Evaluating the impact of rapid antimicrobial susceptibility testing for bloodstream infections: a review of actionability, antibiotic use and patient outcome metrics.

Antimicrobial susceptibility testing (AST) is a core function of the clinical microbiology laboratory and is critical to the management of patients with bloodstream infections (BSIs) to facilitate optimal antibiotic therapy selection. Recent technological advances have resulted in several rapid methods for determining susceptibility direct from positive blood culture that can provide turnaround times in under 8 h, which is considerably shorter than conventional culture-based methods. As diagnostic results do not directly produce a medical intervention, actionability is a primary determinant of the effect these technologies have on antibiotic use and ultimately patient outcomes. Randomized controlled trials and observational studies consistently show that rapid AST significantly reduces time to results and improves antimicrobial therapy for patients with BSI across various methods, patient populations and organisms. To date, the clinical impact of rapid AST has been demonstrated in some observational studies, but randomized controlled trials have not been sufficiently powered to validate many of these findings. This article reviews various metrics that have been described in the literature to measure the impact of rapid AST on actionability, antibiotic exposure and patient outcomes, as well as highlighting how implementation and workflow processes can affect these metrics.

Barriers to implementation of rapid identification and antimicrobial susceptibility testing technologies in the clinical microbiology laboratory: an American perspective.

Clinical microbiology laboratories are responsible for confirming the aetiology of infectious diseases and providing antimicrobial susceptibility testing results. Traditional culture-based testing can be augmented by more rapid testing modalities to provide clinically actionable information as quickly as possible. Despite improvements in patient outcomes, many clinical microbiology laboratories are facing challenges to in-sourcing these technologies. Depending on a multitude of factors, including size, location and patient population served, these barriers may affect some laboratories and hospital systems to greater or lesser extents than others. It will be up to each individual facility to ascertain its ability to overcome barriers. To aid in this self-assessment, we present for thoughtful consideration a discussion of the barriers to implementation of rapid identification and antimicrobial susceptibility testing technologies, with specific attention to matters of financial cost, staff expertise, operational issues and stakeholder buy-in.

Outbreak caused by multidrug-resistant OXA-48 and NDM-1 producing Klebsiella pneumoniae inthe intensive care unit of a cancer hospital.

We report a nosocomial outbreak caused by a multidrug-resistant carbapenemase-producing Klebsiella pneumoniae (MDRCPKp), that was detected in six patients admitted to the medical intensive care unit between 20th of December 2023 and 15th of January 2024 in Ankara, Turkey. The investigation of this outbreak was started on 29th of December 2023. During the outbreak 11 samples were collected from the six patients with MDRCPKp. Pulsed-field gel electrophoresis (PFGE) was performed to determine the genetic relatedness and clonality of MDRCPKp strains. MDRCPKp was isolated in the tracheal aspiration culture, blood, urine, and screening samples. Five patients with MDRCPKp colonization developed healthcare-associated infection. In one patient MDRCPKp was isolated from tracheal aspirate and the screening cultures were considered as colonization not infection. PFGE analysis revealed that all isolates belonged to the same K. pneumoniae clone. MDRCPKp strain of this outbreak exhibited multidrug resistance and co-produced OXA-48 and NDM-1. This outbreak ended after application of strict infection control measures. An outbreak of MDRCPKp can occur in hospitals, especially in the intensive care units; thus, it should be detected early by infection control teams. A strong collaboration between infection control team and microbiology laboratory is essential to cope with MDR bacterial outbreaks in hospitals.

Vulvovaginal candidiasis clinical signs, and distribution of Candida species

Background: Vulvovaginal candidiasis is a global issue of concern due to its association with economic costs, sexually transmitted infections, and ascending genital tract infection. The aim of this study was to determine clinical signs and species distribution of Candida species causing vulvovaginal candidiasis. Methods: A cross-sectional study was conducted from December to June 2021-2024 among 400 women attending Obstetrics and Gynecology outpatient clinics in Sana'a City. The study involved collecting vaginal swabs from each participant and analyzing them in a microbiology laboratory. The swabs were used to identify yeast cells, fungal culturing, and germ tube formation tests. The study also used the VITEK II system to confirm species identification, with the VITEK® 2 YST ID identification card being used to identify Candida species. Results: A study of 400 women found that 91.8% were infected with Candida albicans, while 8.2% were infected with other non-Candida albicans. The majority were aged 26-35, with secondary education being the most common. Most were married, with 1-3 pregnancies. The most common sign distribution was vaginal discharge with a 99.5% prevalence. Dysuria was the lowest, with a 65.0% prevalence. Candida species were most frequently isolated, with Candida albicans being the most common. Candida tropicalis was found in 1 out of 6 women, while Candida dubliniensis, Candida famata, Candida glabrata, and Candida lusitaniae were found in 1 out of 6 women. Conclusions: The high prevalence rate of vulvovaginal candidiasis and observation of a low prevalence rate of nonalbicans Candida species in the present study substantiate the importance of conducting continuous epidemiological surveys to measure changes in species distribution from C. albicans to non-albicans Candida species in Yemen.

Impact of the COVID-19 pandemic on the antimicrobial resistance at the General Hospital level in Republic of Srpska, Bosnia and Herzegovina

<p><strong>Introduction. </strong>Antibiotic resistance is a major threat to public health globally. The aim was to examine the impact of the COVID-19 pandemic on the distribution and antimicrobial resistance of pathogenic microorganisms isolated from samples <br />obtained during standard hospital care in one hospital center.  <br /><strong>Methods.</strong> Data were obtained retrospectively from a database of the hospital microbiology laboratory. Study sample consisted of 3012 samples tested before the pandemic in 2019 and 3130 samples from the pandemic period in 2021. <br /><strong>Results.</strong> There was no statistically significant difference in the occurrence of agents that were resistant to all antibiotics between the observed years, but there was the difference in the occurrence of those agents between departments, with the highest frequency in the intensive care unit and the COVID-19 department (p<0.001). Isolation of Acinetobacter bacteria increased 2.7 times, and Clostridioides difficile 6.4 times during 2021 compared to 2019. Statistically significant differences were registered in resistance to: imipenem, piperacillin-tazobactam, ceftayidime, cefepime, glycopeptides, aminoglycosides, levofloxacin and ciprofloxacin in 2021 compared to 2019. <br /><strong>Conclusion. </strong>Our results suggest possible influence of COVID-19 on antimicrobial resistance and input a need for a new larger study addressing this issue.</p>

Predicting Pseudomonas aeruginosa drug resistance using artificial intelligence and clinical MALDI-TOF mass spectra.

Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) is widely used in clinical microbiology laboratories for bacterial identification but its use for detection of antimicrobial resistance (AMR) remains limited. Here, we used MALDI-TOF MS with artificial intelligence (AI) approaches to successfully predict AMR in Pseudomonas aeruginosa, a priority pathogen with complex AMR mechanisms. The highest performance was achieved for modern β-lactam/β-lactamase inhibitor drugs, namely, ceftazidime/avibactam and ceftolozane/tazobactam. For these drugs, the model demonstrated area under the receiver operating characteristic curve (AUROC) of 0.869 and 0.856, specificity of 0.925 and 0.897, and sensitivity of 0.731 and 0.714, respectively. As part of this work, we developed dynamic binning, a feature engineering technique that effectively reduces the high-dimensional feature set and has wide-ranging applicability to MALDI-TOF MS data. Compared to conventional feature engineering approaches, the dynamic binning method yielded highest performance in 7 of 10 antimicrobials. Moreover, we showcased the efficacy of transfer learning in enhancing the AUROC performance for 8 of 11 antimicrobials. By assessing the contribution of features to the model's prediction, we identified proteins that may contribute to AMR mechanisms. Our findings demonstrate the potential of combining AI with MALDI-TOF MS as a rapid AMR diagnostic tool for Pseudomonas aeruginosa.IMPORTANCEPseudomonas aeruginosa is a key bacterial pathogen that causes significant global morbidity and mortality. Antimicrobial resistance (AMR) emerges rapidly in P. aeruginosa and is driven by complex mechanisms. Drug-resistant P. aeruginosa is a major challenge in clinical settings due to limited treatment options. Early detection of AMR can guide antibiotic choices, improve patient outcomes, and avoid unnecessary antibiotic use. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) is widely used for rapid species identification in clinical microbiology. In this study, we repurposed mass spectra generated by MALDI-TOF and used them as inputs for artificial intelligence approaches to successfully predict AMR in P. aeruginosa for multiple key antibiotic classes. This work represents an important advance toward using MALDI-TOF as a rapid AMR diagnostic for P. aeruginosa in clinical settings.