About

Joan-Miquel Balada-Llasat, PharmD, PhD, is a Professor-Clinical and the Director of Immunology at The Ohio State University Wexner Medical Center. He also serves as the Associate Director of Clinical Microbiology and is an Associate Professor of Pathology at The Ohio State University. His major research and clinical interests focus on the implementation of rapid laboratory tests for diagnosing infectious diseases, with a particular emphasis on low-cost tests suitable for resource-limited areas. Dr. Balada-Llasat is actively involved in global health initiatives related to tuberculosis and HPV in Central America, Africa, and India. He holds board certification from the American Board of Medical Microbiology and has a background that includes extensive training in clinical microbiology, molecular microbiology, and pharmacy, with education from the University of Barcelona, Tufts University School of Medicine, and the University of Washington.

Research topics

• Medicine
• Pathology
• Biology
• Ecology
• Veterinary medicine
• Internal medicine
• Evolutionary biology

Selected publications

• Evaluation of diagnostic practices surrounding foodborne disease in a large university-based healthcare system

  Epidemiology and Infection · 2026-02-12

  articleOpen access

  Each year approximately 47.8 million people in the U.S. fall ill with foodborne disease (FBD), though most never seek medical care for their illness.For those who do seek care, even fewer will have a stool specimen tested to determine a causative agent.These factors contribute to underdiagnosis of FBD.The study objective was to assess underdiagnosis and changes in FBD diagnostic practices over time.A retrospective cohort study using electronic medical records was https://doi.org/10.1017/S0950268826101101

  PublisherOA PDFDOI

• P-816. Diagnostic Performance of Molecular Sample-to-Answer Tests for Bloodstream Infections in the Clinical Setting: a Systematic Literature Review and Meta-Analysis

  Open Forum Infectious Diseases · 2025-01-29

  articleOpen access1st authorCorresponding

  Abstract Background Rapid identification of bloodstream pathogens and antimicrobial resistance (AMR) genes by molecular tests from positive blood cultures (PBCs) have the potential to improve patient management. A systematic review and meta-analysis was conducted to evaluate diagnostic test accuracy (DTA) of molecular tests compared to phenotypic methods for detecting pathogens and AMR genes in the clinical setting.Figure 1.Summary sensitivity and specificity for total gram-negative bacteria and gram-positive bacteria, with subgroup by multiple and single test panel coverage. Methods MEDLINE, EMBASE, and Cochrane databases were searched from inception to October 25, 2023. Search of conference proceedings and forward and backward searching were also done. Studies evaluating DTA of commercially available molecular sample-to-answer tests versus phenotypic methods (reference standard) in adults and children with PBCs were eligible. Risk of bias (RoB) was assessed using QUADAS-2. Summary DTA outcomes were estimated using bivariate random-effects model for gram-negative bacteria (GNB), gram-positive bacteria (GPB), yeast, gram-negative (GN) AMR, gram-positive (GP) AMR, and targets within these groups when reported by ≥ 2 studies (PROSPERO CRD42023488057).Figure 2.Summary sensitivity and specificity for antimicrobial resistance detected in gram-negative bacteria Results Seventy-four studies including 24,634 samples were analyzed, most of which showed low RoB or applicability concerns. Compared with phenotypic methods, molecular tests demonstrated high DTA across all target groups, with sensitivity ≥ 92% and PPV ≥ 99% for total GNB (N=43 studies), GPB (N=38), yeast (N=24), GN AMR (N=35), and GP AMR (N=39). Specificity and NPV were 100% and 98% for GNB and 100% and 97% for GPB, respectively, among molecular tests targeting both groups (not estimable for molecular tests targeting GNB only or GPB only as true negatives are not applicable). Specificity and NPV were ≥ 99% for other target groups. High DTA was also observed for individual pathogen targets (≥ 93% sensitivity, 100% specificity, ≥ 96% PPV, and ≥ 99% NPV). Five of 7 AMR genes had high sensitivity (91%-99%) and specificity (≥ 99%). Sensitivity was lower for 2 carbapenemase genes IMP (N=4; 69%, 95% CI 15%–96%) and VIM (N=4; 70%, 95% CI 38%–90%), of which detection was missed in P. aeruginosa.Figure 3.Summary sensitivity and specificity for antimicrobial resistance detected in gram-positive bacteria Conclusion Results show excellent DTA of molecular sample-to-answer tests compared to traditional culture in identifying a broad panel of pathogens and detecting AMR in GNB and GPB.Table 1.Summary of diagnostic test accuracy outcomes for targets evaluated across studies Disclosures Joan-Miquel Balada-Llasat, PharmD/PhD, bioMerieux: Advisor/Consultant|bioMerieux: Grant/Research Support Tammy C. Bleak, PharmD, MSc, bioMerieux, Inc: employee Sarah Jiudice, MPH, bioMerieux, Inc: employee Tristan T. Timbrook, PharmD, bioMérieux: Stocks/Bonds (Public Company)

  PublisherOA PDFDOI

• Evaluating the efficacy of reprocessing contaminated single use devices for re-use in intensive care unit in Ethiopia

  Antimicrobial Resistance and Infection Control · 2025-12-27

  articleOpen access

  BACKGROUND: Single use devices (SUDs) are designed for single use. However, in low-income countries, they are often reprocessed and reused. Because these devices are intended for single use, no standardized protocol for reprocessing these devices currently exists. We developed a protocol for reprocessing SUDs in low-income settings and assessed the efficacy of this protocol in eliminating bacterial burden from a subset of used respiratory SUDs. METHODS: Reprocessing of these devices was conducted in accordance with the National IPC reference manual with minor modifications. The surfaces of used SUDs were swabbed for bacterial culture before and after reprocessing. Serial dilutions of the swab samples were inoculated on plate count agar media and incubated. Bacterial burden was determined by colony forming unit (CFU) counts. Bacterial isolates were identified and characterized using standard microbiology techniques, antimicrobial susceptibility testing, and modified carbapenem inactivation method in accordance with Clinical and Laboratory Standards Institute guidelines. RESULTS: . Nineteen (54.3%) tested devices were positive for coagulase-negative Staphylococcus, and 19 (54.3%) for Gram-negative organisms: Acinetobacter spp. (n = 7; 36.8%), Klebsiella pneumoniae (n = 6; 31.6%), Pseudomonas aeruginosa (n = 3; 15.8%), Escherichia coli (n = 2; 10.5%), and K. oxytoca (n = 1; 5.3%). Ten (52%) of the Gram-negative organisms were multidrug-resistant. Following reprocessing, no bacterial growth was demonstrated on any of the devices. CONCLUSION: The reprocessing protocol employed in this study demonstrated absence of culturable bacteria from used SUDs. However, since the assessment was limited to surface swabbing of a small number of devices collected from a single facility and targeted only selected bacterial pathogens, the presence of other potential pathogens could not be completely ruled out. There is a need to assess the impact of the reprocessing procedure on the structural integrity and functionality of these devices. If SUDs are being reused, the efficacy of the decontamination method should be ascertained to mitigate the risk of transmission of pathogens between patients.

  PublisherDOI

• Development and evaluation of the phenotypic 2G test to detect drug-resistant TB

  IJTLD OPEN · 2025-11-01

  articleOpen access

  SUMMARY BACKGROUND Early diagnosis of TB with drug susceptibility testing (DST) is critical to achieve successful treatment outcomes. We aimed to develop and test a novel colorimetric, 12-well, thin-layer agar-based test to assess its accuracy for TB diagnosis and DST in a clinical setting in Southern Mozambique. METHODS Development of the first prototype of the second generation (2G) test in the laboratory setting followed by a cross-sectional diagnostic accuracy study with consecutive recruitment of subjects with microbiologically confirmed TB using GeneXpert MTB/RIF Ultra. RESULTS In the laboratory setting, the 2G test showed 100% accuracy in detecting resistance of genotypically characterised drug-resistant Mycobacterium tuberculosis strains. In the clinical setting, the sensitivity of the 2G test to detect M.tb complex versus Xpert and Mycobacteria Growth Indicator Tube (MGIT) culture using fresh sputa was 45.9% and 45.2%, respectively. The 2G test sensitivity versus MGIT decreased to 23.1% when using frozen decontaminated sputum samples. CONCLUSION In the clinical setting, the 2G test showed a low sensitivity versus Xpert and MGIT. The 2G test sensitivity was lower when frozen instead of fresh sputa was used. Despite these results, important information was collected to further improve this 2G test prototype and its implementation in resource-constrained settings.

  PublisherDOI

• Gram-negative bacterial sepsis, antimicrobial susceptibility pattern and treatment outcomes at two neonatal intensive care units in Addis Ababa, Ethiopia: A retrospective observational study

  PLoS ONE · 2025-05-13

  articleOpen access

  BACKGROUND: Neonatal sepsis is a leading cause of mortality and morbidity. To improve the clinical outcomes of neonates with sepsis, treatment should be based on bacteriological identification and antibiotic susceptibility. This study aims to assess the proportion of culture-positive gram-negative bacteria (GNB), the antibiotic susceptibility patterns, and treatment outcomes of neonatal sepsis at two neonatal intensive care units (NICUs) in Addis Ababa. METHODS: A retrospective observational study was conducted among gram-negative sepsis suspected neonates admitted at Zewditu Memorial Hospital and Tikur Anbessa Specialized Hospital NICUs from January to December 2023. All neonates who were suspected of having sepsis were included in this study. Standard microbiological culture and biochemical tests were used to identify bacterial species and the Kirby-Bauer disc diffusion assay using Mueller-Hinton agar was employed to test the antimicrobial susceptibility of bacterial isolates as per Clinical Laboratory Standard Institute guidelines. Descriptive statistics were used to describe the study variables. Bivariable and multivariable logistic regression analyses were used to identify the factors associated with the treatment outcomes of neonatal sepsis. A p-value < 0.05 was set for statistical significance. RESULTS: A total of 933 neonates were diagnosed with sepsis during the study period, of which 166 neonates were enrolled in the study for gram-negative sepsis: 84 (51%) were female and 97 (58%) had early onset sepsis. The median length of hospital stay was nine days with interquartile range of 16 days. The predominant GNB identified was Klebsiella spp. (n = 89; 49%), followed by Acinetobacter spp. (n = 38; 21%) and Escherichia coli (n = 19; 11%). In both hospitals, Klebsiella spp. was resistant to most of the routinely prescribed antibiotics: (n = 68; 89%) were resistant to ceftriaxone, (n = 56, 89%) cefepime and (n = 60; 75%) to gentamicin. Lower rates of resistance were recorded for other antibiotics such as ciprofloxacin (n = 12; 18%), ertapenem (n = 11; 16%), meropenem (n = 9; 13%), and amikacin (n = 3; 4%). A total of 92 (55%) neonates with the GNB isolated in the current study had multidrug-resistant (MDR) organisms. The study found that newborns with MDR infections were five times more likely to experience poor treatment outcomes compared to those with non-resistant strains (AOR, 5.23 95% CI [2.59, 11.11]). In addition, newborns who stayed less than seven days, compared to those who spent seven or more days in the hospital was four times (AOR: 4.16, 95% CI (2.0-9.01) more likely to experience poor health outcomes. CONCLUSION: Klebsiella spp. was the most common GNB isolated from the NICUs. More than half neonatal sepsis was caused by MDR organisms and associated with significant poor treatment outcomes. high prevalence of MDR-gram-negative bacteremia is alarming and highlights the need for the implementation of routine surveillance and infection control measures to decrease morbidity and mortality and to combat the development of antimicrobial resistance.

  PublisherDOI

• Performance of molecular tests for diagnosis of bloodstream infections in the clinical setting: a systematic literature review and meta-analysis

  Clinical Microbiology and Infection · 2024-12-11 · 17 citations

  reviewSenior author
  PublisherDOI

• Impact of the COVID-19 Pandemic on Foodborne Disease Healthcare-Seeking Behavior and Diagnoses at a Large Academic Medical System

  Foodborne Pathogens and Disease · 2024-09-04 · 1 citations

  article

  The objective of this study was to examine changes in healthcare-seeking behaviors and diagnostic practices around foodborne illness during the COVID-19 pandemic in a large university-based health system. A retrospective cohort study of individuals diagnosed with pathogens commonly transmitted through food between 2015 and 2020 was undertaken using electronic medical record data. Regression models were used to compare measured incidence rates of various foodborne pathogens as well as associated healthcare-seeking behaviors during the pandemic year of 2020 to previous years. Incidence of campylobacteriosis, cholera, and norovirus in 2020 significantly decreased, respectively, by 65.5% ( p &lt; 0.01), 90.1% ( p = 0.02), and 73.0% ( p = 0.03) compared with an average from 2017– to 019. Average annual visits for patients included in our sample significantly increased by 8.0% when comparing the average from 2017–2019 to 2020 ( p &lt; 0.01). These results suggest that the pandemic impacted healthcare use related to foodborne disease either due to reduced exposure to foodborne pathogens or reduced willingness to seek healthcare.

  PublisherDOI

• Use of Whole Genome Sequencing for Investigation of Potential Hospital-Acquired Vancomycin Resistant Enterococcus

  Antimicrobial Stewardship & Healthcare Epidemiology · 2024-07-01

  articleOpen access

  Background: Whole genome sequencing (WGS) is a relatively new method for analyzing outbreaks and modes of transmission, particularly for multidrug resistant bacteria. This study sought to investigate clusters of patients with genetically related Vancomycin-Resistant Enterococcus spp. (VRE) bacteremia for shared hospital environmental exposures. Methods: All VRE blood culture isolates from patients from July 1, 2021 to June 30, 2022 underwent Illumina WGS. Core single nucleotide polymorphisms (SNPs) were identified, and multi-locus sequence typing (MLST) was performed across the VRE isolates. Clusters were defined as isolates with 15 or fewer core genome SNPs and were investigated for potential transmission routes. For each cluster, patients were evaluated in the 12 weeks before and after the first VRE isolate for shared hospital environmental exposures (hospital unit, patient rooms, procedural rooms, and radiology suites). Hospital units were comprised of patient rooms located geographically together on the same floor of the hospital. Results: A total of 82 VRE isolates underwent WGS. Thirty-eight (46%) clustered genetically with at least one other isolate. Clusters included 2 to 15 patients per group and represented 10 distinct MLST subgroups (Figure 1). Nine hundred and thirty-nine hospital environmental exposures were identified across the 38 patients. For each cluster, there was a total of 341 (36.3%) shared exposures. Shared environmental exposures occurred in radiology suites (35, 38.5%), patient rooms (32, 35.6%) and procedural rooms (23, 25.6%). Of the patients who shared the same hospital unit, 10 (31.3%) had the same patient room with 7 (70%) of them being in the emergency department (ED). Overall, the ED represented 7 (21.9%) of the shared hospital units. Each cluster had at least one shared hospital environmental exposure found. Conclusions: Use of WGS can help investigate outbreak clusters of resistant organisms such as VRE. In this study, nearly half of all VRE blood isolates were able to be segregated into clusters with at least one other isolate. Although VRE colonization of hospital rooms is well described, patient rooms represented the smallest proportion of shared hospital environmental exposures. This study thus suggests other environmental transmission routes such as radiology suites and procedural rooms warrant closer investigation.

  PublisherOA PDFDOI

• Reply to Kidd et al., “Inconsistencies within the proposed framework for stabilizing fungal nomenclature risk further confusion”

  Journal of Clinical Microbiology · 2024-03-05 · 1 citations

  letterOpen access

  International audience

  PublisherOA PDFDOI

• Antimicrobial Resistance and Virulence Gene Profile of Clinical Staphylococcus aureus: A Multi-Center Study from Ethiopia

  Infection and Drug Resistance · 2023-07-01 · 9 citations

  articleOpen access

  Background: Staphylococcus aureus causes a wide range of infections from mild skin and soft tissue to severe life-threatening bacteremia. The pathogenicity of S. aureus infections is related to various bacterial surface components and extracellular proteins such as toxic-shock syndrome (TSS) toxin and Panton-Valentine leukocidin (PVL). In this study we determine the antimicrobial resistance of isolated strains and their virulence genes in Ethiopia. Methods: A total of 190 archived S. aureus isolates from four Ethiopia Antimicrobial Resistance (AMR) Surveillance sites were analyzed. The identification of S. aureus was done by matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF Biotyper) and antimicrobial susceptibility test (AST) was done using VITEK ® 2. Multiplex PCR was used to detect mecA, mecC, pvl and spa genes and super-antigens ( sea, seb, sec, seh and sej staphylococcal enterotoxins). Results: A total of 172 isolates were confirmed as S. aureus , 9 (5.23%) were methicillin-resistant S. aureus (MRSA) and 163 (94.76%) were methicillin-susceptible S. aureus (MSSA). AST showed that 152 (88.4%) isolates were resistant to penicillin; 90 (52.32%) resistant to trimethoprim-sulfamethoxazole; and 45 (26.16%) resistant to tetracycline. A total of 66 (38.37%) isolates harbored at least one staphylococcal enterotoxin gene and 31 (46.96%) isolates had more than one. The most frequent enterotoxin gene encountered was seb 28 (16.28%). The TSST-1 gene was detected in 23 (13.37%). Presence of staphylococcal enterotoxin gene showed significant association with antibiotic resistance to cefoxitin, benzylpenicillin, oxacillin, erythromycin, clindamycin, tetracycline and SXT. The pvl gene was detected in 102 (59.3%) of isolates. Isolates from patients below 15 years of age showed significantly high numbers of pvl gene (P = 0.02). Presence of sej (P = 0.011) and TSST-1 (P < 0.001) genes were associated with the presence of pvl gene. Conclusion: In this study, isolates were highly resistant to oral antibiotics and the pvl, seb, sea and TSST-1 genes were prevalent. Keywords: MRSA, enterotoxin genes, Panton-Valentine leucocidin, PVL, Ethiopia

  PublisherOA PDFDOI

Frequent coauthors

• Preeti Pancholi

  50 shared

• Shuhua Wang

  People's Liberation Army 401 Hospital

  20 shared

• Debra A. Goff

  The Ohio State University Wexner Medical Center

  15 shared

• Karri A. Bauer

  Merck & Co., Inc., Rahway, NJ, USA (United States)

  15 shared

• Wondwossen A. Gebreyes

  The Ohio State University

  14 shared

• Kurt Stevenson

  Boise VA Medical Center

  13 shared

• Carlton A. Evans

  12 shared

• Keelie Thomas

  The Ohio State University Wexner Medical Center

  10 shared

Labs

• Computational Pathology LabPI

Education

• Ph.D., Molecular Biology and Microbiology

  Tufts University School of Medicine

  2006

• Other, Molecular Microbiology

  Tufts University School of Medicine

  1998

• Other

  College of Pharmacy, University of Barcelona

  1991