Background and Objective: Methicillin-resistant Staphylococcus aureus (MRSA) is one of the leading causes of hospital and community-acquired infections, showing antimicrobial resistance (AMR), which is an increasing public health concern. One of the commonly-used methods to evaluate resistance include the Kirby-Bauer disk diffusion method. However, this test is found to be time-consuming, lacking in terms of mechanization and automation, alongside its non-applicability to certain antibiotics such as vancomycin. Thus, the Clinical Laboratory Standards Institute (CLSI) recommends using the broth microdilution method in the evaluation of antibacterial activities against S. aureus. A rapid laboratory identification of MRSA is important in the treatment of patients. Therefore, this study aims to optimize and evaluate the effectiveness of a rapid microplate assay using resazurin dye as a colorimetric indicator in determining antibacterial activity against clinical isolates of MRSA and methicillin-susceptible S. aureus (MSSA). Methods: Clinical isolates of MRSA and MSSA were obtained from the Philippine General Hospital (PGH) Microbiology Section, and American Type Culture Collection (ATCC) controls of both strains (ATCC 25923 and ATCC 43300) were acquired. These were then subjected to identification and confirmation procedures. A standardization of bacterial inoculum was performed by comparing its 24-hr growth in Mueller Hinton Broth to 0.5 McFarland Standard. The resazurin microplate assay (REMA) was set-up using two-fold serial dilution of control antibiotics such as oxacillin, vancomycin, and cefoxitin. Each plate was inoculated with standardized bacterial growth of controls and clinical isolates. To determine the time needed for the reduction of the resazurin dye, a qualitative assessment was conducted by comparing the reaction time between a 6.75 mg/mL dye with a 0.01 mg/mL dye. The plates were also subjected to different incubation times and dye concentrations, and the optical densities of the plates were compared using a microplate reader. Results: Results showed that there were no significant differences between the optical densities of the wells of those incubated for 5 hours and for 24 hours (p >0.05). Furthermore, there was a significant reduction in the reaction time of the dye (from 18 hours to 1 hour) when the dye concentration was reduced from 6.75 mg/mL to 0.01 mg/mL. The optimized REMA showed a significant difference between the minimum inhibitory concentrations (MICs) of the different antibiotics against the control and isolate strains of MRSA and MSSA, showing a W of -2.98 (p <0.05) using the Wilcoxon Rank-Sum non-parametric test. Furthermore, the REMA has shown better illustration of anti-MRSA and anti-MSSA activities as compared to the Kirby Bauer disk diffusion method. Conclusion Based on the results presented, the researchers determined the optimal condition for the resazurin microtiter assay, which was 0.01 g/mL concentration of resazurin dye, at a 5-hour incubation period. This study has shown that an optimized REMA is an efficient and fast method to determine the antimicrobial activities of oxacillin, cefoxitin, and vancomycin against MRSA and MSSA.
Methicillin Resistant Staphylococcus aureus

Objectives The implementation of Philippine National Standard PNS ISO 15189:2013 to support the medical laboratory to produce competent results is a recognised challenge. It is apparent that the approach of ensuring the equipment availability can be specifically optimised. No known research has focused on exploring on the conduct of conformity evaluation of Afinion 2 Analyzer maintainability for the PNS ISO 15189:2013 accredited medical laboratory. The aim of the current study was to develop a practical tool for the medical laboratory to support the internal audit process by determining the compliance status of Afinion 2 Analyzer maintainability.
Accreditation

Objectives: The implementation of Philippine National Standard PNS ISO 15189:2013 to support the medical laboratory to produce competent results is a recognised challenge. It is apparent that the approach of ensuring the equipment availability can be specifically optimised. No known research has focused on exploring on the conduct of conformity evaluation of Afinion 2 Analyzer maintainability for the PNS ISO 15189:2013 accredited medical laboratory. The aim of the current study was to develop a practical tool for the medical laboratory to support the internal audit process by determining the compliance status of Afinion 2 Analyzer maintainability. Methods The relevant conformance requirements in Clauses 4 (Management requirements) and 5 (Technical requirements) of PNS ISO 15189:2013, manufacturer requirements and specific requirements for accreditation from 70/101 (69%) accreditation bodies in 80/249 (32%) countries were identified as specific audit criteria for Afinion 2 Analyzer conformity evaluation checklists for the maintenance and reference equipment.

Objectives: The primary aim of this study was to determine quantitatively the extent of coverage of the Hong Kong Laboratory Accreditation Scheme (HOKLAS 015) requirements by guidance checklists (HOKLAS 016‑02 and HOKLAS 021). Methods: The level of conformance requirement coverage of HOKLAS 015 by HOKLAS 016‑02 and HOKLAS 021 was calculated by an evaluation checklist based on conformance requirements in HOKLAS 015. A distribution analysis of conformance requirements relating to the International Standard ISO 15189:2012 process‑based quality management system model was also performed to elicit further coverage information. Results: HOKLAS 016‑02 was found to provide coverage of 76% while HOKLAS 021 was found to provide coverage of 11%. HOKLAS 015 was also found to have a distribution coverage of 78% relating to the International Standard ISO 15189:2012 process‑based quality management system model. Conclusion The results of this analysis should be of value to medical laboratories wishing to maintain the internal auditability required by HOKLAS 015 by gaining an awareness of the extent of coverage provided by HOKLAS 016‑02 and HOKLAS 021.
Accreditation ; Management Audit

BACKGROUND AND OBJECTIVE

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the leading causes of hospital and community-acquired infections, showing antimicrobial resistance (AMR), which is an increasing public health concern. One of the commonly-used methods to evaluate resistance include the Kirby-Bauer disk diffusion method. However, this test is found to be time-consuming, lacking in terms of mechanization and automation, alongside its non-applicability to certain antibiotics such as vancomycin. Thus, the Clinical Laboratory Standards Institute (CLSI) recommends using the broth microdilution method in the evaluation of antibacterial activities against S. aureus. A rapid laboratory identification of MRSA is important in the treatment of patients. Therefore, this study aims to optimize and evaluate the effectiveness of a rapid microplate assay using resazurin dye as a colorimetric indicator in determining antibacterial activity against clinical isolates of MRSA and methicillin-susceptible S. aureus (MSSA).

Clinical isolates of MRSA and MSSA were obtained from the Philippine General Hospital (PGH) Microbiology Section, and American Type Culture Collection (ATCC) controls of both strains (ATCC 25923 and ATCC 43300) were acquired. These were then subjected to identification and confirmation procedures. A standardization of bacterial inoculum was performed by comparing its 24-hr growth in Mueller Hinton Broth to 0.5 McFarland Standard. The resazurin microplate assay (REMA) was set-up using two-fold serial dilution of control antibiotics such as oxacillin, vancomycin, and cefoxitin. Each plate was inoculated with standardized bacterial growth of controls and clinical isolates. To determine the time needed for the reduction of the resazurin dye, a qualitative assessment was conducted by comparing the reaction time between a 6.75 mg/mL dye with a 0.01 mg/mL dye. The plates were also subjected to different incubation times and dye concentrations, and the optical densities of the plates were compared using a microplate reader.

Results showed that there were no significant differences between the optical densities of the wells of those incubated for 5 hours and for 24 hours (p >0.05). Furthermore, there was a significant reduction in the reaction time of the dye (from 18 hours to 1 hour) when the dye concentration was reduced from 6.75 mg/mL to 0.01 mg/mL. The optimized REMA showed a significant difference between the minimum inhibitory concentrations (MICs) of the different antibiotics against the control and isolate strains of MRSA and MSSA, showing a W of -2.98 (pCONCLUSION

Based on the results presented, the researchers determined the optimal condition for the resazurin microtiter assay, which was 0.01 g/mL concentration of resazurin dye, at a 5-hour incubation period. This study has shown that an optimized REMA is an efficient and fast method to determine the antimicrobial activities of oxacillin, cefoxitin, and vancomycin against MRSA and MSSA.

BACKGROUND AND OBJECTIVES

COVID-19 has quickly spread over the world and became an unprecedented burden on health care systems. COVID-19 diagnosis necessitates the use of precise testing methods such as RT-PCR. This method is generally reported as positive or negative, however, studies have shown its semi-quantitative capability through Ct values. This study determined an association that exists between the Ct values, clinical features, and laboratory findings among COVID-19 patients admitted in a tertiary infectious disease hospital in Manila, Philippines. This attempts to further explore the utility of RT-PCR in disease severity classification and diagnosis.

This was an observational retrospective study that utilized a purposive sampling method, wherein patients were selected based on the DOH case definition of confirmed COVID-19, and were stratified according to disease severity. Baseline laboratory data of the patients were gathered from medical records covering the period of June 2021 to January 2022 using a Data Collection Form. Chi-square test was used to measure the degree of association between the groups and categorical variables. Regression Analysis was used to identify predictors for certain variables. SPSS Statistics for Windows, Version 25.0 was utilized for the statistical analysis.

The total WBC, neutrophil, lymphocyte and monocyte counts, serum urea, LDH, CRP and PTT were found to be predictors of COVID-19 severity. There was no significant difference observed between the disease severity and the patient’s clinical outcome. All routine laboratory tests that were taken at baseline (ORF Gene, N-Gene, Hematocrit, White Blood Cells, Neutrophil, Lymphocyte, Monocyte, Platelet Count, Urea, Creatinine, SGPT, SGOT, Na, K, LDH, Ferritin, C Reactive Protein, Procalcitonin, D-Dimer, PT, PTT) were not significant predictors of the clinical outcome. Although WBC, neutrophil, lymphocyte, and monocyte count, urea, LDH, CRP, and PTT were predictors  of disease severity. The study also reported that the odds of having severe to critical disease increases by 20.6% for every one unit increase in neutrophil count, and 17.4% for every one unit increase in lymphocyte count. Among the laboratory parameters, neutrophil count (p=0.010654063) and urea (p= 0.04149874 have direct relationship with the N gene Ct values while Orf gene Ct Values have direct relationship with lymphocyte count (p=0.01269027). Similarly, regression showed that as monocyte count, creatinine levels, and serum ferritin decrease, Ct values increase. Sex was found to not be a significant predictor of disease severity and clinical outcome. There was also no significant difference observed between the disease severity and the patient’s clinical outcome.

The study showed that the Ct values for both ORF and N genes were not significant predictors of both disease severity and clinical outcome. However, ORF gene Ct values have direct relationship with lymphocyte counts while N gene Ct values have direct correlation with neutrophil count and urea levels. Similarly, monocyte, creatinine, and ferritin are negatively correlated with Ct values. It is important to monitor the patient’s laboratory biomarkers in order to determine the proper course of treatment and management for each case.

BACKGROUND AND OBJECTIVE

The human nasal passages host major human pathogens. Recent research suggests that the microbial communities inhabiting the epithelial surfaces of the nasal passages play a key factor in maintaining a healthy microenvironment by affecting both resistance to pathogens and immunological responses. Colonization of the nasal cavity by different pathogens such as Staphylococcus aureus and Klebsiella aerogenes, is associated with a higher postoperative infection morbidity. Povidone-iodine (PVP-I) as an antiseptic has been proven to display high antibacterial, antiviral, and antifungal properties even at low concentrations, and was shown to be effective in the control of infections to limit their impact and spread. It can be used as a topical antiseptic for skin decontamination and wound management, as a nasal spray, or as a gargle. There are different methods in testing the efficacy of potential antimicrobial suspensions. This study aimed to determine the concentration of PVP-I that is most effective in nasal decolonization using microsuspension test and colorimetric minimum inhibitory concentration (MIC) determination assays, resazurin microtiter assay (REMA), and Dey-Engley (D/E) neutralizer assay. The findings of this study will contribute to knowledge regarding the intended use of PVP-I in microbial control, particularly in bacterial infections.

Several dilutions (2.0%, 1.0%, 0.5%, 0.25%, 0.1% and 0.09%) of commercially bought 10% (10 mg per 100 ml) povidone-iodine were prepared and tested against a standardized inoculum (1x105) of Staphylococcus aureus and Klebsiella aerogenes at different contacttimes (5 seconds, 10 seconds, 30 seconds, 1 minute, and 5 minutes). Microdilution suspension test was performed to determine the log reduction per variable, while REMA and D/E neutralizer assay were used to determine the MIC. A value of greater than or equal to 5 log reduction was considered effective for microdilution suspension test. Estimates of agreement statistics were used to interpret the results of the assay in which the overall percent agreement (OPA), positive percent agreement (PPA), negative percent agreement (NPA), and Cohen’s kappa statistics were calculated.

Povidone-iodine concentration of 0.25% exhibited ?5 log reduction against K. aerogenes at the minimum contact time of 5 seconds. On the other hand,  a slightly higher PVP-I concentration was required to achieve ?5 log reduction for S. aureus at 0.5% concentration and a minimum contact time of 1 minute. There was an observed concordance of the results of REMA and D/E neutralizer as MIC colorimetric indicators, which yielded an overall test percent agreement of 90.30% (95% CI: 84.73–94.36), and a strong level of agreement (? = 0.8, pCONCLUSION

Low povidone-iodine concentrations (i.e., 0.5% against S. aureus and 0.25% against K. aerogenes) were observed to have bactericidal activity of at least 5 log reduction as rapid as the minimum contact time of 5 seconds. Furthermore, D/E and REMA, as colorimetric indicators, had comparable performance (OPA = 90.30%; ? = 0.8, p
Human ; Bacteria ; Povidone-iodine ; Microbial Sensitivity Tests ; Anti-infective Agents, Local ; Enterobacter Aerogenes ; Staphylococcus Aureus