The inhibitory effects of carvacrol, nystatin, and their combination on oral candidiasis isolates.

BACKGROUND: Candida, a common oral microbiota, can cause opportunistic fungal infections. With rising Candida infections and limited effective antifungals, new treatments are needed. This study investigates carvacrol essential oil's effect on oral candidiasis, alone and with nystatin, compared to nystatin alone. MATERIALS AND METHODS: In this study, oral samples were collected from dental clinic patients, especially denture users. The presence of Candida was confirmed and cultured from these samples. Candidiasis was detected by observing Candida colonies. Drug sensitivity was tested on 100 positive samples. The minimum concentration of inhibition and lethality of each isolate was evaluated using nystatin and carvacrol. The results were compared using two-way analysis of variance. Finally, the minimum inhibitory concentration (MIC) of nystatin and carvacrol was calculated individually and in combination. RESULTS: The present study found that Candida albicans and non-albicans species were equally prevalent. Carvacrol showed significant biological activity against all Candida species, with an average MTT of 50.01%. The average MIC value of carvacrol was 24.96 µg/ml, indicating its potential to inhibit Candida growth. The mean Minimum Fungicidal Concentration (MFC) value of carvacrol was 23.48 µg/ml, suggesting its effectiveness in killing the fungi. CONCLUSION: The study's findings reveal that the MIC of carvacrol was significantly lower than that of nystatin and the combination of nystatin and carvacrol. This suggests that carvacrol holds potential as an effective herbal remedy for candidiasis.

Anti-Candida activity and in vitro toxicity screening of antifungals complexed with ß-cyclodextrin.

The emergence of resistant fungal species and the toxicity of currently available antifungal drugs are relevant issues that require special consideration. Cyclodextrins inclusion complexes could optimize the antimicrobial activity of such drugs and create a controlled release system with few side effects. This study aimed to assess the in vitro toxicity and antifungal effectiveness of nystatin (Nys) and chlorhexidine (Chx) complexed or not with ß-cyclodextrin (ßCD). First, a drug toxicity screening was performed through the Artemia salina bioassay. Then, the minimum inhibitory concentrations (MICs) against Candida albicans were determined with the broth microdilution test. After MICs determination, the cytotoxicity of the drugs was evaluated through the methyl-thiazolyl-tetrazolium (MTT) and neutral red (NR) assays and through cell morphology analysis. The PROBIT analysis was used to determine the median lethal concentration (LC50), and the cell viability values were submitted to one-way analysis of variance(ANOVA)/Tukey (α = 0.05). Overall, the ßCD-complexed antifungals were less toxic against A. salina than their raw forms, suggesting that inclusion complexes can reduce the toxicity of drugs. The MICs obtained were as follows: Nys 0.5 mg/L; Nys:ßCD 4 mg/L; Chx 4 mg/L; and Chx:ßCD 8 mg/L. Chx showed significant cytotoxicity (MTT: 12.9 ± 9.6%; NR: 10.6 ± 12.5%) and promoted important morphological changes. Cells exposed to the other drugs showed viability above 70% with no cellular damage. These results suggest that antifungals complexed with ßCD might be a biocompatible option for the treatment of Candida-related infections.

Candidemia in Adult Patients in the ICU: A Reappraisal of Susceptibility Testing and Antifungal Therapy.

OBJECTIVE: To provide updates on the epidemiology and recommendations for management of candidemia in patients with critical illness. DATA SOURCES: A literature search using the PubMed database (inception to March 2023) was conducted using the search terms "invasive candidiasis," "candidemia," "critically ill," "azoles," "echinocandin," "antifungal agents," "rapid diagnostics," "antifungal susceptibility testing," "therapeutic drug monitoring," "antifungal dosing," "persistent candidemia," and "Candida biofilm." STUDY SELECTION/DATA EXTRACTION: Clinical data were limited to those published in the English language. Ongoing trials were identified through ClinicalTrials.gov. DATA SYNTHESIS: A total of 109 articles were reviewed including 25 pharmacokinetic/pharmacodynamic studies and 30 studies including patient data, 13 of which were randomized controlled clinical trials. The remaining 54 articles included fungal surveillance data, in vitro studies, review articles, and survey data. The current 2016 Infectious Diseases Society of America (IDSA) Clinical Practice Guideline for the Management of Candidiasis provides recommendations for selecting empiric and definitive antifungal therapies for candidemia, but data are limited regarding optimized dosing strategies in critically ill patients with dynamic pharmacokinetic changes or persistent candidemia complicated. RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE: Outcomes due to candidemia remain poor despite improved diagnostic platforms, antifungal susceptibility testing, and antifungal therapy selection for candidemia in critically ill patients. Earlier detection and identification of the species causing candidemia combined with recognition of patient-specific factors leading to dosing discrepancies are crucial to improving outcomes in critically ill patients with candidemia. CONCLUSIONS: Treatment of candidemia in critically ill patients must account for the incidence of non-albicans Candida species and trends in antifungal resistance as well as overcome the complex pathophysiologic changes to avoid suboptimal antifungal exposure.

Antimicrobial resistance patterns and empiric antibiotic selections for patients admitted from post-acute care facilities.

PURPOSE: To characterize the susceptibilities of positive bacterial cultures and the appropriateness of empiric antimicrobial regimens for patients admitted from post-acute care facilities (PACFs). METHODS: This was a retrospective quality improvement study. The study included patients admitted from a PACF to one of 2 tertiary care teaching hospitals within the University of Pennsylvania Health System, located in Philadelphia, PA, from August 2020 to December 2021. Patients were included if they had at least one positive culture within 72 hours of admission. RESULTS: A total of 167 patients and 230 isolates from the study period were evaluated. The majority of positive cultures were from a urinary source (114 of 230, 49.6%). Nineteen patients (11.4%) had a history of multidrug-resistant organisms. The most common empiric antibiotics used were vancomycin (61.7%) and cefepime (59.3%). Sixty-one patients (36.5%) received inappropriate empiric therapy based on the culture results. When comparing our hospitals' general antibiogram to that of only PACF patients, Escherichia coli and Klebsiella pneumoniae had at least a 20% difference in susceptibility to levofloxacin, ceftriaxone, and cefepime. Extended-spectrum ß-lactamase resistance was also higher in the PACF cohort (odds ratio, 2.09; 95% confidence interval, 1.4-3.1). CONCLUSION: Clinically significant differences in antimicrobial susceptibility were found among patients admitted from PACFs compared to our health system's general antibiogram. The increased resistance rates identified in this study support the need for hospitals to evaluate this at-risk patient population, which may drive changes to empiric antibiotic prescribing practices.

The effect of TiO2 nanoparticles on bacterial growth: the effect of particle size and their structure - a systematic review.

One of the widely used microbiological methods to determine the toxicity of chemicals, catalysts, and other types of materials is the minimum inhibitory concentration (MIC) test. The present study aims to investigate the influence of composition of composite materials based on TiO2 and their particle size as well as bacterial type and shape based on the MIC values reported in the literature. The results show that among the 36 articles selected, most of the studies used Escherichia coli (E. coli) (26) and Staphylococcus aureus (S. aureus) (19) bacteria to determine MIC values. This study revealed that the MIC in values below 70 µg ml-1 for S. aureus was lower than that for E. coli bacteria (below 200 µg ml-1). Importantly, MIC value decreased from 60.6 to 7.66 µg ml-1 with decrease in the size of nanoparticles. It follows from the increased surface area for smaller-sized particles, thus increased interaction with bacteria during MIC test.

Prevalence and antimicrobial resistance profile of pathogens isolated from patients with urine tract infections admitted to a university hospital in a medium-sized Brazilian city

ABSTRACT This study aimed to determine the antibiotic profile of microorganisms isolated from urine samples of patients with community urine tract infections (UTI) admitted to the University Hospital of the Federal University of Sao Carlos to support an appropriate local empirical treatment. A retrospective cross-sectional study was conducted from October 2018 to October 2020. Data from 1,528 positive urine cultures for bacterial pathogens and antibiograms were tabulated. Bacterial species prevalence and their resistance profile were analyzed and compared by sex and age. For Gram-negative fermenting bacteria, resistance rates were compared between patients with previous hospitalization and the total of infections caused by this group. For comparisons, the Chi-square test was performed, using Fisher's exact test when necessary (BioEstat program, adopting p ≤ 0.05). A multivariate analysis was applied to assess the effect of the studied variables in predicting multidrug resistance. Infections were more prevalent in women and older adults. Gram-negative bacteria represented 90.44% of total cultures. In both sexes, E. coli prevalence was significantly higher in adults compared with older adults (p < 0.0001). For several antibiotics, resistance rates were higher in the older adults compared with other ages and in patients with Gram-negative fermenting infections and previous hospitalization compared with the total of infections by this group of bacteria. The closer to the hospitalization, the higher the number of antibiotics with superior resistance rates. Resistance rates for aminoglycosides, carbapenems, ceftazidime, nitrofurantoin, piperacillin+tazobactam, and fosfomycin were less than 20%, considered adequate for empirical treatment. Only hospitalization in the previous 90 days was statistically significant in predicting infections by multidrug-resistant bacteria.

[Comparison of Epsilometer test and agar dilution method in detecting the sensitivity of Helicobacter pylori to metronidazole].

OBJECTIVE: Agar dilution method (ADM) was used as the golden standard to evaluate the consistency of Epsilometer test (E-test) in detecting the sensitivity of Helicobacter pylori (H. pylori) to metronidazole. METHODS: From August 2018 to July 2020, patients with H. pylori infection treated for the first time in Peking University Third Hospital for gastroscopy due to dyspepsia were included in this study. Gastric mucosas were taken from the patients with H. pylori infection. H. pylori culture was performed. Both the ADM and E-test were applied to the antibiotic susceptibility of H. pylori to metro-nidazole, and the consistency and correlation between the two methods were validated. RESULTS: In the study, 105 clinical isolates of H. pylori were successfully cultured, and the minimum inhibitory concentration ≥ 8 mg/L was defined as drug resistance. Both ADM and the E-test showed high resistance rates to metronidazole, 64.8% and 62.9%, respectively. Among them, 66 drug-resistant strains were detected by ADM and E-test, and 37 were sensitive strains, so the consistency rate was 98.1%. Two strains were evaluated as drug resistance by ADM, but sensitive by the E-test, with a very major error rate of 1.9%. There was zero strain sensitive according to ADM but assessed as resistant by the E-test, so the major error rate was 0%. Taking ADM as the gold standard, the sensitivity of E-test in the detection of metronidazole susceptibility was 97.1% (95%CI: 0.888-0.995), and the specificity was 100% (95%CI: 0.883-1.000). Cohen's kappa analysis showed substantial agreement, and kappa coefficient was 0.959 (95%CI: 0.902-1.016, P < 0.001). Spearmans correlation analysis confirmed this correlation was significant (r=0.807, P < 0.001). The consistency evaluation of Bland-Altman method indicated that it was good, and there was no measured value outside the consistency interval. In this study, cost analysis, including materials and labor, showed a 32.2% higher cost per analyte for ADM as compared with the E-test (356.6 yuan vs. 269.8 yuan). CONCLUSION: The susceptibility test of H. pylori to metronidazole by E-test presents better agreement with ADM. Because it is less expensive, less labor intensive, and more rapid, it is an easy and reliable method for H. pylori susceptibility testing.

Applications of Lab on a Chip in Antimicrobial Susceptibility of Staphylococcus aureus: A Systematic Review.

Background and Objectives: Staphylococcus aureus is a prevalent bacterium capable of inducing various infections, including skin and soft tissue infections, bloodstream infections, pneumonia, and surgical site infections. The emergence of antimicrobial resistance in S. aureus, particularly methicillin-resistant S. aureus, has raised substantial concerns within global healthcare settings. Prior to antibiotic prescription, the ideal approach is antimicrobial susceptibility testing (AST); however, this is frequently perceived as excessively complex and time-intensive. Lab-on-a-chip (LOC) technology holds promise in addressing these challenges and advancing fundamental microbiological research while also aiding in the development of therapeutic strategies. This systematic review aims to evaluate the potential utility of LOC for AST of S. aureus. Materials and Methods: This study adhered to the PRISMA guidelines. Various databases, including SCOPUS, PubMed/MEDLINE, SCIELO, and LILACS, in addition to gray literature sources, were employed in the review process. Results: Sixteen studies were included in this systematic review. All these studies detailed the effectiveness, rapidity, and predictability of LOC systems for assessing S. aureus susceptibility to various antibiotics. When comparing the LOC approach to traditional manual methods, it was evident that LOC requires a minimal quantity of reagents. Furthermore, most studies reported that the entire LOC procedure took 10 min to 7 h, with results being equally accurate as those obtained through traditional AST protocols. Conclusions: The potential application of LOC for AST of S. aureus is emphasized by its ability to provide rapid access to minimum inhibitory concentration data, which can substantially aid in selecting the most suitable antibiotics and dosages for treating challenging infections caused by this microorganism. Moreover, the rapid AST facilitated by LOC holds promise for enhancing the appropriateness and efficacy of therapy in clinical settings.

In vitro sensitivity of Malassezia furfur isolates from HIV-positive and negative patients to antifungal agents / Sensibilidad in vitro a antifúngicos de aislamientos de Malassezia furfur de pacientes positivos y negativos para HIV

INTRODUCTION: Malassezia is a lipophilic and lipid-dependent yeast genus belonging to the skin microbiota of humans and other animals. However, due to dysbiosis processes or other factors in the host, this yeast can cause different pathologies, ranging from skin diseases, such as seborrheic dermatitis, to fungemia. Isolation of Malassezia furfur has been reported in HIV-positive patients with or without skin lesions. Due to its opportunistic nature and its variable resistance to antifungal compounds, it is relevant to know the Malassezia sensitivity profiles. OBJECTIVE: To determine the sensitivity to different antifungal agents, of clinical isolates of M. furfur obtained from HIV-positive or negative patients, with or without seborrheic dermatitis. MATERIALS AND METHODS: Assessment of isolates sensitivity to itraconazole, voriconazole, fluconazole, and amphotericin B was performed by two techniques: (1) Broth microdilution using Clinical and Laboratory Standards Institute (CLSI) protocol M27-A3 with modifications; and (2) agar tests using Etest®. RESULTS: Isolates obtained from HIV patients showed an increase in the minimum inhibitory concentration of fluconazole, voriconazole, and amphotericin B, compared with those of non-HIV patients. Itraconazole was the antifungal with the lowest minimum inhibitory concentration (MIC) in most isolates. CONCLUSION: We observed differences in the sensitivity profiles of M. furfur isolates according to the context of the patient. High MIC of antifungals like fluconazole, commonly used for treating pathologies caused by Malassezia, were identified.

Introducción: Malassezia es un género de levaduras lipofílicas que dependen de los lípidos y hacen parte de la microbiota de la piel de humanos y otros animales. No obstante, debido a procesos de disbiosis u otros factores en el huésped, esta levadura puede llegar a causar diferentes enfermedades: desde cutáneas (como dermatitis seborreica) hasta fungemias. Se han reportado aislamientos de Malassezia furfur en pacientes positivos para HIV, con lesiones cutáneas o sin ellas. Por su carácter oportunista y sensibilidad variable a los compuestos antifúngicos, es relevante conocer los perfiles de sensibilidad. Objetivo: Determinar la sensibilidad a diferentes antifúngicos de aislamientos clínicos de M. furfur obtenidos de pacientes positivos o negativos para HIV, con dermatitis seborreica o sin ella. Materiales y métodos: La sensibilidad de los aislamientos a itraconazol, voriconazol, fluconazol y anfotericina B, se determinó mediante dos técnicas: microdilución en caldo según el protocolo M27-A3 del Clinical & Laboratory Standards Institute (CLSI), con modificaciones, y pruebas en agar mediante Etest®. Resultados: Los aislamientos obtenidos de pacientes con HIV mostraron aumento de la concentración inhibitoria mínima a fluconazol, voriconazol y anfotericina B, en comparación con los de pacientes sin HIV. Por otro lado, al evaluar la mayoría de los aislamientos, el itraconazol fue el antifúngico con la menor concentración inhibitoria mínima. Conclusión: Se evidencian diferencias en los perfiles de sensibilidad de los aislamientos de M. furfur, según el contexto del paciente, y elevadas concentraciones inhibitorias mínimas de antifúngicos como el fluconazol, usados comúnmente para el tratamiento de las enfermedades causadas por Malassezia spp.

In vitro sensitivity of Malassezia furfur isolates from HIV-positive and negative patients to antifungal agents / Sensibilidad in vitro a antifúngicos de aislamientos de Malassezia furfur de pacientes positivos y negativos para HIV

Introduction. Malassezia is a lipophilic and lipid-dependent yeast genus belonging to the skin microbiota of humans and other animals. However, due to dysbiosis processes or other factors in the host, this yeast can cause different pathologies, ranging from skin diseases, such as seborrheic dermatitis, to fungemia. Isolation of Malassezia furfur has been reported in HIV-positive patients with or without skin lesions. Due to its opportunistic nature and its variable resistance to antifungal compounds, it is relevant to know the Malassezia sensitivity profiles. Objective. To determine the sensitivity to different antifungal agents, of clinical isolates of M. furfur obtained from HIV-positive or negative patients, with or without seborrheic dermatitis. Materials and methods. Assessment of isolates sensitivity to itraconazole, voriconazole, fluconazole, and amphotericin B was performed by two techniques: (1) Broth microdilution using Clinical and Laboratory Standards Institute (CLSI) protocol M27-A3 with modifications; and (2) agar tests using Etest®. Results. Isolates obtained from HIV patients showed an increase in the minimum inhibitory concentration of fluconazole, voriconazole, and amphotericin B, compared with those of non-HIV patients. Itraconazole was the antifungal with the lowest minimum inhibitory concentration (MIC) in most isolates. Conclusion. We observed differences in the sensitivity profiles of M. furfur isolates according to the context of the patient. High MIC of antifungals like fluconazole, commonly used for treating pathologies caused by Malassezia, were identified.

Introducción. Malassezia es un género de levaduras lipofílicas que dependen de los lípidos y hacen parte de la microbiota de la piel de humanos y otros animales. No obstante, debido a procesos de disbiosis u otros factores en el huésped, esta levadura puede llegar a causar diferentes enfermedades: desde cutáneas (como dermatitis seborreica) hasta fungemias. Se han reportado aislamientos de Malassezia furfur en pacientes positivos para HIV, con lesiones cutáneas o sin ellas. Por su carácter oportunista y sensibilidad variable a los compuestos antifúngicos, es relevante conocer los perfiles de sensibilidad. Objetivo. Determinar la sensibilidad a diferentes antifúngicos de aislamientos clínicos de M. furfur obtenidos de pacientes positivos o negativos para HIV, con dermatitis seborreica o sin ella. Materiales y métodos. La sensibilidad de los aislamientos a itraconazol, voriconazol, fluconazol y anfotericina B, se determinó mediante dos técnicas: microdilución en caldo según el protocolo M27-A3 del Clinical & Laboratory Standards Institute (CLSI), con modificaciones, y pruebas en agar mediante Etest®. Resultados. Los aislamientos obtenidos de pacientes con HIV mostraron aumento de la concentración inhibitoria mínima a fluconazol, voriconazol y anfotericina B, en comparación con los de pacientes sin HIV. Por otro lado, al evaluar la mayoría de los aislamientos, el itraconazol fue el antifúngico con la menor concentración inhibitoria mínima. Conclusión. Se evidencian diferencias en los perfiles de sensibilidad de los aislamientos de M. furfur, según el contexto del paciente, y elevadas concentraciones inhibitorias mínimas de antifúngicos como el fluconazol, usados comúnmente para el tratamiento de las enfermedades causadas por Malassezia spp.

Septic arthritis of the temporomandibular joint managed with arthroscopy: a case report.

Septic arthritis of the temporomandibular joint (SATMJ) is an uncommon bacterial or fungal infection of the joint space. A 68-year-old man with underlying diabetes mellitus and a history of liver transplant, who was on immunosuppressants, presented to the oral and maxillofacial surgery department of the authors´ institution in Portugal. His main symptoms were arthralgia in the right temporomandibular joint, malocclusion, pre-auricular swelling and erythema. After clinical, laboratory, and imaging evaluations, diagnoses of chronic suppurative otitis media and SATMJ were made. The patient was managed with arthroscopy of the right temporomandibular joint, which allowed joint fluid collection for microbiological examination, lavage, and biopsy. The biopsy sample was positive for Pseudomonas aeruginosa. After surgery, targeted intravenous antibiotic treatment (amikacin) was given for 30 days. No recurrence of any complaints was reported after 12 months of follow-up.

Susceptibility-guided sequential strategy versus empirical therapy for Helicobacter pylori infection: study protocol for a randomised controlled trial.

BACKGROUND: New treatment strategies are required against infections caused by Helicobacter pylori, which grows increasingly resistant to antibiotics. Polymerase chain reaction-based methods for antibiotic susceptibility testing are available for detecting H. pylori-specific mutations that confer resistance to clarithromycin and levofloxacin. Several meta-analyses have compared eradication rates for susceptibility-guided versus empirical therapy for H. pylori treatment; however, all have significant limitations and high heterogeneity, and the results are contradictory. The main objective of this trial is to assess whether a sequential strategy based on molecular susceptibility testing-guided therapy for H. pylori has a better eradication rate than empirical therapy. METHODS: This trial is designed as a prospective, randomised, open-label, active-controlled and single-centre study. Men and women who are H. pylori-positive, naïve to treatment, and aged 18-65 years will be recruited. A total of 500 participants will be randomised to receive either empirical therapy or a susceptibility-guided sequential strategy. Bismuth quadruple therapy will be the empirical first-line therapy, and in case of failure, high-dose dual (proton-pump inhibitor + amoxicillin) treatment will be the rescue therapy. For the susceptibility-guided sequential strategy, regimen selection will be based on H. pylori susceptibility to clarithromycin (first-line) and levofloxacin (rescue). A first-line treatment of clarithromycin triple therapy will be selected for clarithromycin-sensitive strains. For clarithromycin resistance, a high-dose dual therapy will be selected. During the rescue treatment, a levofloxacin quadruple regimen will be selected for levofloxacin-sensitive strains, and a furazolidone quadruple regimen will be selected for others. The primary outcome is the first-line eradication rate in both groups, and the overall (including first and rescue therapies) H. pylori eradication rate in both groups is one of the secondary outcomes. The eradication rates of H. pylori will be analysed by intention-to-treat analysis, modified intention-to-treat analysis, and per-protocol analysis. DISCUSSION: This randomised controlled trial will provide objective and valid evidence about the value of polymerase chain reaction-based molecular methods for antibiotic susceptibility testing in guiding H. pylori eradication. TRIAL REGISTRATION: Clinicaltrials.gov NCT05549115. Released on 18 September 2022. First posted on 22 September 2022. Enrolment of the first participant on 20 September 2022. The study is retrospectively registered.

Infecciones causadas por Staphylococcus aureus de la Comunidad. Estudio de sensibilidad y tendencias en población pediátrica. Años 2015 a 2020

Introducción: Staphylococcus aureus (SA) puede ocasionar cuadros infecciosos severos y muerte. La emergencia de cepas resistentes a meticilina constituye un desafío terapéutico. Objetivos: determinar el perfil de resistencia antimicrobiana de: Staphylococcus aureus adquirido en la comunidad (SA-CA), obtenidos de muestras biológicas de niños, entre 2015 a 2020. Material y Método: estudio descriptivo, observacional y retrospectivo. Las muestras para cultivos se extrajeron al ingreso hospitalario del paciente. Para determinación de resistencia y sensibilidad se utilizó normas de CSLI. Resultados: 244 aislamientos de SA-CA. Masculinos 99 (59%), menores de un año: 42 (25%), de 2 a 5 años: 34 (20%), de 6 a 11 años: 50 (30%) y entre 12 a 15 años: 42 (25%). De los aislados, 72% fueron SAMR (121/168) y 28% SAMS (47/168). Se observó un incremento de tasas anuales de aislamientos SAMR en infecciones de la comunidad desde el 2015 al 2020. Los aislamientos se originaron en piel y partes blandas 53,2 %; sangre 37,4%, orina 3,5%, LCR 2,4%, liquido articular 1,7%, abscesos profundos 1,2% y liquido pleural 0,6%. La prevalencia de SAMR-CA fue de 60,5 en el 2015, 59,6 %, 61,5%, 72,2 %, 67,3% y 75,5 % en los años sucesivos. No se aisló ninguna cepa resistente a la vancomicina. El 10,1% de las cepas estudiadas presentó resistencia inducida a la clindamicina. Conclusión: El SAMR se ha establecido como patógeno de la comunidad. La resistencia inducida por clindamicina fue del 10,1%. Un tercio de las infecciones fueron causadas por SAMS. Las prevalencias de SAMS muestran tendencia a la disminución.

Introduction: Staphylococcus aureus (SA) can cause severe infectious conditions and death. The emergence of methicillin-resistant strains constitutes a therapeutic challenge. Objectives: to determine the antimicrobial resistance profile of: Staphylococcus aureus acquired in the community (SA-CA), obtained from biological samples of children, between 2015 and 2020. Material and Method: descriptive, observational and retrospective study. The samples for cultures were extracted upon hospital admission of the patient. To determine resistance and sensitivity, CSLI standards were used. Results: 244 isolates of SA-CA. Males 99 (59%), under one-year-old: 42 (25%), from 2 to 5 years old: 34 (20%), from 6 to 11 years old: 50 (30%) and between 12 and 15 years old: 42 (25%). Of the isolates, 72% were SAMR (121/168) and 28% SAMS (47/168). An increase in annual rates of MRSA isolates in community infections was observed from 2015 to 2020. The isolates originated in skin and soft parts 53.2 %; blood 37.4%, urine 3.5%, CSF 2.4%, joint fluid 1.7%, deep abscesses 1.2% and pleural fluid 0.6%. The prevalence of MRSA-CA was 60.5 in 2015, 59.6%, 61.5%, 72.2%, 67.3%, and 75.5% in subsequent years. No vancomycin resistant strain was isolated. 10.1% of the strains studied presented induced resistance to clindamycin. Conclusion: MRSA has been established as a community pathogen. The resistance induced by clindamycin was 10.1%. One third of the infections was caused by SAMS. The prevalence of SAMS shows a downward trend.

Clinical characteristics and drug resistance profile of patients with endobronchial tuberculosis in South Korea: single-center experience.

BACKGROUND: Tuberculosis (TB) is a major infectious disease worldwide; there has been a significant increase in the number of elderly patients with TB, largely contributing to TB-related mortality. Although endobronchial tuberculosis (EBTB) is a unique form of pulmonary TB, available data on the clinical characteristics and drug susceptibility (DST) patterns of patients with EBTB are scarce. METHODS: We evaluated the clinical characteristics of patients with EBTB in South Korea and the culture-based DST patterns of EBTB. Further, the DST patterns were compared between elderly (≥65 years) and young (<65 years) patients. We retrospectively reviewed data of patients with EBTB who had the results of DST and were diagnosed between January 2013 and December 2019 at a tertiary referral hospital in South Korea. Phenotypic DST of 15 first-line and second-line anti-TB drugs was performed using Mycobacterium tuberculosis isolates prior to treatment. RESULTS: Of the 230 patients with EBTB, 69% were in elderly patients (≥65 years). Any-resistance occurred in 24 patients (10.4%), while multi-drug resistance (MDR) and extensive drug resistance (XDR) were observed in six patients (2.6%). Compared to that of the elderly treatment-naïve patients, previously treated elderly patients had a significantly higher proportion of resistance to rifampin (14.3% vs. 2.2%; P=0.031), ethambutol (9.5% vs. 0.7%; P=0.046), and pyrazinamide (9.5% vs. 0.7%; P=0.046). Further, MDR/XDR was observed more frequently in the previously treated elderly patients than that in the treatment-naïve elderly patients (14.3% vs. 1.4%; P=0.017). A relatively small number of drug-resistant cases (5.6%) were observed in young patients. CONCLUSIONS: Elderly EBTB patients with previous Anti-tuberculous medications had a significantly higher proportion of drug-resistant TB. These patients should be carefully assessed using DST analysis before treatment.

High levels of antimicrobial resistance in Escherichia coli and Salmonella from poultry in Ecuador.

Objective: To describe antimicrobial resistance profiles of Escherichia coli and Salmonella spp. isolated from chicken carcasses and the antimicrobials commonly used in animals in Ecuador and provide information on antimicrobial resistance patterns for implementing evidence-based corrective measures. Methods: Meat samples were collected from chicken carcasses in 199 slaughterhouses across Ecuador as part of a national pilot study for monitoring antimicrobial resistance in agricultural sources in 2019. Samples were tested for E. coli and Salmonella spp. Sensitivity to 10 critically important and three highly important antimicrobials (from a human health perspective) was assessed. The country report submitted to the World Organization for Animal Health was accessed to extract the quantity of antimicrobials produced or imported for use in animals. Results: Of 383 samples, E. coli was isolated from 148 (39%) and Salmonella spp. from 20 (5%) samples. Ninety percent of the isolates were resistant to at least one critically important antimicrobial. Resistance was highest to erythromycin (E. coli 76%; Salmonella spp. 85%) and tetracycline (E. coli 71%; Salmonella spp. 90%). Critically or highly important antimicrobials (colistin, tetracycline, trimethoprim/sulfamethoxazole) formed the bulk (87%) of antimicrobials used in animals as per the World Organization for Animal Health report. Conclusions: High prevalence of antimicrobial resistance in poultry in Ecuador calls for the development of guidelines and regulations on the use of antimicrobials and for engagement with livestock producers. The existing surveillance system needs to be strengthened to improve the monitoring of antimicrobial use and evolving resistance patterns.

Development of multiplex real-time PCR for detection of clarithromycin resistance genes for the Mycobacterium abscessus group.

Introduction. The M. abscessus molecular identification and its drug-resistance profile are important to choose the correct therapy.Aim. This work developed a multiplex real-time PCR (mqPCR) for detection of clarithromycin resistance genes for the Mycobacterium abscessus group.Methodology. Isolates received by Adolfo Lutz Institute from 2010 to 2012, identified by PCR restriction enzyme analysis of a fragment of the hsp65 gene (PRA-hsp65) as M. abscessus type 1 (n=135) and 2 (n=71) were used. Drug susceptibility test (DST) for CLA were performed with reading on days 3 and 14. Subespecies identification by hsp65 and rpoB genes sequencing and erm(41) and rrl genes for mutation detection and primer design were performed. erm(41) gene deletion was detected by conventional PCR. Primers and probes were designed for five detections: erm(41) gene full size and with deletion; erm(41) gene T28 and C28; rrl gene A2058.Results. In total, 191/206 (92.7 %) isolates were concordant by all methods and 13/206 (6.3 %) were concordant only between molecular methods. Two isolates (1.0 %) were discordant by mqPCR compared to rrl gene sequencing. The mqPCR obtained 204/206 (99.0 %) isolates in agreement with the gold standard, with sensitivity and specificity of 98 and 100 %, respectively, considering the gold standard method and 92 and 93 % regarding DST.Conclusion. The mqPCR developed by us proved to be an easy-to-apply tool, minimizing time, errors and contamination.

Antibacterial Effects of X-ray and MRI Contrast Media: An In Vitro Pilot Study.

Some radiological contrast agents have been shown to have effects on bacterial growth. In this study, the antibacterial effect and mechanism of action of iodinated X-ray contrast agents (Ultravist 370, Iopamiro 300, Telebrix Gastro 300 and Visipaque) and complexed lanthanide MRI contrast solutions (MultiHance and Dotarem) were tested against six different microorganisms. Bacteria with high and low concentrations were exposed to media containing different contrast media for various lengths of time and at pH 7.0 and 5.5. The antibacterial effect of the media was examined in further tests using agar disk diffusion analysis and the microdilution inhibition method. Bactericidal effects were found for microorganisms at low concentrations and low pH. Reductions were confirmed for Staphylococcus aureus and Escherichia coli.

Molecular epidemiology and antifungal susceptibilities of Aspergillus species isolated from patients with invasive aspergillosis

SUMMARY OBJECTIVE: The aim of this study was to evaluate the demographic data, molecular epidemiology, and in vitro antifungal susceptibility results of patients with Aspergillus isolated from various clinical specimens. METHODS: A total of 44 Aspergillus strains were studied. The definition of invasive aspergillosis in patients was made according to European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) criteria. Strains were phenotypically and molecularly identified. Demographic characteristics of patients and genotypes of strains were evaluated. Phylogenetic analysis was done by the The Unweighted Pair-Group Method with Arithmetic Mean (UPGMA). Antifungal susceptibility of strains was determined according to The Clinical and Laboratory Standards Institute (CLSI)-M61-Ed2 and The European Committee on Antimicrobial Susceptibility Testing (EUCAST). RESULTS: A total of 11 patients were classified as proven and 33 as probable invasive aspergillosis. There was a statistically significant difference in age groups, subdisease, neutropenic, and receiving chemotherapy between groups. A total of 23 strains were identified as Aspergillus fumigatus, 12 as Aspergillus niger, 6 as Aspergillus flavus, and 3 as Aspergillus terreus. Phylogenetic analysis revealed five different genotypes. No statistical difference was found in the comparisons between patients groups and genotype groups. There was a statistically significant difference between genotype groups and voriconazole, posaconazole, and itraconazole Minimum Inhibition Concentration (MIC). CONCLUSION: Accurate identification of strains and antifungal susceptibility studies should be performed due to azole and amphotericin B resistance. Genotyping studies are important in infection control due to identifying sources of infection and transmission routes.

High levels of antimicrobial resistance in Escherichia coli and Salmonella from poultry in Ecuador / Niveles elevados de resistencia antimicrobiana de las bacterias Escherichia coli y Salmonella en aves de corral en Ecuador / Altos níveis de resistência aos antimicrobianos em Escherichia coli e Salmonella de aves de criação no Equador

ABSTRACT Objective. To describe antimicrobial resistance profiles of Escherichia coli and Salmonella spp. isolated from chicken carcasses and the antimicrobials commonly used in animals in Ecuador and provide information on antimicrobial resistance patterns for implementing evidence-based corrective measures. Methods. Meat samples were collected from chicken carcasses in 199 slaughterhouses across Ecuador as part of a national pilot study for monitoring antimicrobial resistance in agricultural sources in 2019. Samples were tested for E. coli and Salmonella spp. Sensitivity to 10 critically important and three highly important antimicrobials (from a human health perspective) was assessed. The country report submitted to the World Organization for Animal Health was accessed to extract the quantity of antimicrobials produced or imported for use in animals. Results. Of 383 samples, E. coli was isolated from 148 (39%) and Salmonella spp. from 20 (5%) samples. Ninety percent of the isolates were resistant to at least one critically important antimicrobial. Resistance was highest to erythromycin (E. coli 76%; Salmonella spp. 85%) and tetracycline (E. coli 71%; Salmonella spp. 90%). Critically or highly important antimicrobials (colistin, tetracycline, trimethoprim/sulfamethoxazole) formed the bulk (87%) of antimicrobials used in animals as per the World Organization for Animal Health report. Conclusions. High prevalence of antimicrobial resistance in poultry in Ecuador calls for the development of guidelines and regulations on the use of antimicrobials and for engagement with livestock producers. The existing surveillance system needs to be strengthened to improve the monitoring of antimicrobial use and evolving resistance patterns.

RESUMEN Objetivo. Describir los perfiles de resistencia antimicrobiana de las bacterias Escherichia coli y Salmonella spp. aisladas en carne de pollo y los antimicrobianos comúnmente empleados en animales en Ecuador, así como proporcionar información sobre los patrones de resistencia a los antimicrobianos para poner en marcha medidas correctivas basadas en la evidencia. Métodos. Se recogieron muestras de carne de pollo en 199 mataderos de todo Ecuador en el marco de un estudio piloto nacional para monitorear la resistencia a los antimicrobianos en fuentes agrícolas en el 2019. Se analizaron las muestras en busca de E. coli y Salmonella spp. Se evaluó la sensibilidad a diez antimicrobianos de importancia crítica y tres muy importantes (para la salud humana). Se accedió al informe de país presentado ante la Organización Mundial de Sanidad Animal para obtener la cantidad de antimicrobianos producidos o importados para su uso en animales. Resultados. De 383 muestras, se aisló E. coli en 148 (39%) y Salmonella spp. en 20 (5%). En total, 90% de las cepas aisladas fueron resistentes a al menos un antimicrobiano de importancia crítica. Hubo una mayor resistencia a la eritromicina (E. coli: 76%; Salmonella spp.: 85%) y a la tetraciclina (E. coli: 71%; Salmonella spp.: 90%). Los antimicrobianos de importancia crítica o muy importantes (colistina, tetraciclina, trimetoprima/sulfametoxazol) constituyeron la mayor parte (87%) de los antimicrobianos empleados en animales según el informe de la Organización Mundial de Sanidad Animal. Conclusiones. Debido a la alta prevalencia de la resistencia a los antimicrobianos en las aves de corral en Ecuador, son imprescindibles la elaboración de directrices y regulaciones sobre el uso de antimicrobianos y el compromiso con los productores pecuarios. Es necesario fortalecer el sistema de vigilancia existente para mejorar el seguimiento del uso de antimicrobianos y de la evolución de los patrones de resistencia.

RESUMO Objetivo. Descrever perfis de resistência aos antimicrobianos em Escherichia coli e Salmonella spp. isoladas de carcaças de frango e os antimicrobianos comumente usados em animais no Equador e fornecer informações sobre padrões de resistência aos antimicrobianos para implementar medidas corretivas baseadas em evidências. Métodos. Foram coletadas amostras de carne de carcaças de frango em 199 abatedouros em todo o Equador como parte de um estudo piloto nacional para monitorar a resistência aos antimicrobianos de origem agrícola em 2019. Foram testadas amostras de E. coli e Salmonella spp. Foi avaliada a sensibilidade a 10 agentes antimicrobianos de importância crítica e três agentes antimicrobianos muito importantes (do ponto de vista da saúde humana). O relatório do país apresentado à Organização Mundial de Saúde Animal foi acessado para extrair a quantidade de antimicrobianos produzidos ou importados para uso em animais. Resultados. De 383 amostras, E. coli foi isolada em 148 (39%) e Salmonella spp. em 20 (5%). Noventa por cento dos isolados foram resistentes a pelo menos um antimicrobiano de importância crítica. A resistência foi maior à eritromicina (E. coli, 76%; Salmonella spp., 85%) e à tetraciclina (E. coli, 71%; Salmonella spp., 90%). Antimicrobianos de importância crítica ou muito importantes (colistina, tetraciclina, trimetoprim/sulfametoxazol) responderam pela maior parte (87%) dos antimicrobianos utilizados em animais, conforme o relatório da Organização Mundial de Saúde Animal. Conclusões. A alta prevalência de resistência aos antimicrobianos na avicultura no Equador exige o desenvolvimento de diretrizes e regulamentos sobre o uso de antimicrobianos e o envolvimento com os produtores de gado e avícolas. O sistema de vigilância existente precisa ser reforçado para melhorar o monitoramento do uso de antimicrobianos e a evolução dos padrões de resistência.