Molecular Epidemiology, Antimicrobial Surveillance, and PK/PD Analysis to Guide the Treatment of Neisseria gonorrhoeae Infections.

The aim of this study was to apply molecular epidemiology, antimicrobial surveillance, and PK/PD analysis to guide the antimicrobial treatment of gonococci infections in a region of the north of Spain. Antibiotic susceptibility testing was performed on all isolates (2017 to 2019, n = 202). A subset of 35 isolates intermediate or resistant to at least two antimicrobials were selected to search for resistance genes and genotyping through WGS. By Monte Carlo simulation, we estimated the probability of target attainment (PTA) and the cumulative fraction of response (CFR) of the antimicrobials used to treat gonorrhea, both indicative of the probability of treatment success. In total, 2.0%, 6.4%, 5.4%, and 48.2% of the isolates were resistant to ceftriaxone, cefixime, azithromycin, and ciprofloxacin, respectively. Twenty sequence types were identified. Detected mutations were related to antibiotic resistance. PK/PD analysis showed high probability of treatment success of the cephalosporins. In conclusion, multiple populations of N. gonorrhoeae were identified. We can confirm that ceftriaxone (even at the lowest dose: 250 mg) and oral cefixime are good candidates to treat gonorrhea. For patients allergic to cephalosporins, ciprofloxacin should be only used if the MIC is known and ≤0.125 mg/L; this antimicrobial is not recommended for empirical treatment.

Haemophilus influenzae Type a Sequence Type 23, Northern Spain.

Two consecutive cases of Haemophilus influenzae type a sequence type 23 invasive infection in 2 children attending the same daycare in 2019 triggered epidemiologic surveillance of H. influenzae infections in northern Spain. Despite the invasiveness potential of this virus strain, we detected no additional cases for 2013-2020.

Pharmacokinetic/Pharmacodynamic Analysis of Tedizolid Phosphate Compared to Linezolid for the Treatment of Infections Caused by Gram-Positive Bacteria.

Tedizolid and linezolid have antibacterial activity against the most important acute bacterial skin and skin-structure infection (ABSSSIs) pathogens. The objective of this work was to apply PK/PD analysis to evaluate the probability of attaining the pharmacodynamic target of these antimicrobials based on the susceptibility patterns of different clinical isolates causing ABSSSI. Pharmacokinetic and microbiological data were obtained from the literature. PK/PD breakpoints, the probability of target attainment (PTA) and the cumulative fraction of response (CFR) were calculated by Monte Carlo simulation. PTA and CFR are indicative of treatment success. PK/PD breakpoints of tedizolid and linezolid were 0.5 and 1 mg/L, respectively. Probability of treatment success of tedizolid was very high (>90%) for most staphylococci strains, including MRSA and coagulase-negative staphylococci (CoNS). Only for methicillin- and linezolid-resistant S. aureus (MLRSA) and linezolid resistant (LR) CoNS strains was the CFR of tedizolid very low. Except for LR, daptomycin-non-susceptible (DNS), and vancomycin-resistant (VRE) E. faecium isolates, tedizolid also provided a high probability of treatment success for enterococci. The probability of treatment success of both antimicrobials for streptococci was always higher than 90%. In conclusion, for empiric treatment, PK/PD analysis has shown that tedizolid would be adequate for most staphylococci, enterococci, and streptococci, even those LR whose linezolid resistance is mediated by the cfr gene.

Penicillin susceptibility among invasive MSSA infections: a multicentre study in 16 Spanish hospitals.

OBJECTIVES: To determine the prevalence of penicillin susceptibility among MSSA causing bloodstream infections (BSIs) in 16 Spanish hospitals and to characterize the penicillin-susceptible MSSA (MSSA-PENS) isolates. METHODS: A total of 1011 Staphylococcus aureus isolates were collected from blood cultures in 16 Spanish hospitals during 2018-19 (6-12 months) and their susceptibility to 18 antimicrobials was determined. The MSSA-PENS isolates were selected and examined by PCR to determine the presence of the blaZ gene, other resistance genes and the genes lukF/lukS-PV, eta, etb and tst. The immune evasion cluster (IEC) type was also analysed. All the MSSA-PENS isolates were submitted to S. aureus protein A (spa) typing and the clonal complexes (CCs) were assigned according to their spa type. RESULTS: The prevalence of MSSA was 74.6% (754/1011) and 14.9% (151/1011) were MSSA-PENS-blaZnegative. MSSA-PENS-blaZnegative isolates (n = 151) were ascribed to 88 spa types and 11 CCs. The most frequent CCs were CC5 (35/151) and CC398 (25/151), with t002-CC5 and t571-CC398 being the most common lineages. Pan-susceptibility was identified in 117 of the 151 MSSA-PENS-blaZnegative isolates (77.5%). In the remaining isolates, erythromycin and clindamycin resistance was the most frequent resistance found, although tobramycin, ciprofloxacin, fusidic acid, mupirocin and/or tetracycline resistance was also detected. Thirty-eight MSSA-PENS-blaZnegative isolates were IEC negative and four isolates were Panton-Valentine leucocidin ('PVL') positive. CONCLUSIONS: A high penicillin susceptibility rate was detected among MSSA, opening therapeutic opportunities for BSIs. The emergence of new successful MSSA-PENS clones could be responsible for these data. The detection among MSSA-PENS-blaZnegative isolates of the clonal lineage CC398 or the absence of an IEC raises questions about their possible animal origin, requiring further analysis.

Are oral cefuroxime axetil, cefixime and cefditoren pivoxil adequate to treat uncomplicated acute pyelonephritis after switching from intravenous therapy? A pharmacokinetic/pharmacodynamic perspective / Cefuroxima axetilo, cefixima y cefditoren pivoxil, ¿son adecuadas en la terapia secuencial de la pielonefritis aguda no complicada? Perspectiva farmacocinética y farmacodinámica

OBJECTIVES: The goal of this study is to assess, by means of pharmacokinetic/pharmacodynamic (PK/PD) analysis using the Monte Carlo simulation, the adequacy of oral cephalosporins cefuroxime axetil, cefixime and cefditoren at different dosing regimens as switch therapy after intravenous cephalosporin treatment in uncomplicated acute pyelonephritis. METHODS: The methodology included: (I) dosing regimen selection and acquisition of pharmacokinetic data; (II) microbiological data acquisition; and (III) Monte Carlo simulation to estimate the PTA (probability of PK/PD target attainment) and CFR (cumulative fraction of response), as indicators of treatment success. RESULTS: At the current susceptibility breakpoints defined by EUCAST and CLSI for either cefuroxime axetil or cefixime, the probability of bactericidal target attainment is zero for the dosage regimens simulated. Considering the bactericidal target %fT > MIC > 70%, the likelihood of the cefuroxime 500- mg q8 h regimen or the cefixime 200- mg q12h regimen producing this exposure or achieving this target is only above 90% for organisms yielding MICs ≤ 0.5 mg/l and MICs ≤ 0.25 mg/l, respectively. Cefditoren pivoxil 400 mg q12h provided probabilities of bactericidal target attainment of 80% or higher for MICs ≤ 0.03 mg/l, and ≤ 0.25 mg/l if considering total instead of free drug concentrations. CONCLUSIONS: The results of the PK/PD target attainment analysis reveal that the likelihood of treatment success based upon the current breakpoints proposed by either EUCAST or CLSI is low. Of the three cephalosporins, cefixime 400 mg q12 h prove to be the best option in oral APN treatment, although this regimen is currently off label

OBJETIVOS: El objetivo de este estudio es evaluar, mediante el análisis farmacocinético/farmacodinámico (PK/PD) empleando la simulación de Montecarlo, la idoneidad de las cefalosporinas orales cefuroxima axetilo, cefixima y cefditoren en diferentes regímenes de dosificación, como terapia secuencial tras el tratamiento intravenoso con cefalosporinas, en pielonefritis aguda no complicada. MÉTODOS: La metodología incluyó: 1) selección del régimen de dosificación y adquisición de datos farmacocinéticos; 2) adquisición de datos microbiológicos; y 3) simulación de Montecarlo para estimar la probabilidad de alcanzar el objetivo (PTA) PK/PD y la fracción de respuesta acumulada (CFR), como indicadores del éxito del tratamiento. RESULTADOS: Para los puntos de corte de sensibilidad actuales definidos por EUCAST y CLSI para cefuroxima axetilo o cefixima, la probabilidad de alcanzar el objetivo bactericida es cero para los regímenes de dosificación simulados. Teniendo en cuenta el objetivo bactericida %fT > MIC > 70%, la probabilidad de que el régimen de cefuroxima 500 mg/cada 8h o el régimen de cefixima 200 mg/cada 12 h produzca esta exposición o alcance este objetivo es solo superior al 90% para los organismos que producen MIC ≤ 0,5 mg/l y MIC ≤ 0,25 mg/l, respectivamente. Cefditoren pivoxil 400 mg/cada 12 h proporcionó probabilidades de alcanzar el objetivo bactericida del 80% o más para MIC ≤ 0,03 mg/l, y ≤ 0,25 mg/l si se considera el fármaco total en lugar de libre. CONCLUSIONES: Los resultados del análisis PK/PD revelan que la probabilidad de éxito del tratamiento basado en los puntos de corte actuales propuestos por EUCAST o CLSI es baja. De las 3 cefalosporinas, la cefixima 400mg/cada 12h resultó ser la mejor opción en el tratamiento oral de pielonefritis aguda, aunque este régimen está actualmente fuera de ficha técnica

Are oral cefuroxime axetil, cefixime and cefditoren pivoxil adequate to treat uncomplicated acute pyelonephritis after switching from intravenous therapy? A pharmacokinetic/pharmacodynamic perspective.

OBJECTIVES: The goal of this study is to assess, by means of pharmacokinetic/pharmacodynamic (PK/PD) analysis using the Monte Carlo simulation, the adequacy of oral cephalosporins cefuroxime axetil, cefixime and cefditoren at different dosing regimens as switch therapy after intravenous cephalosporin treatment in uncomplicated acute pyelonephritis. METHODS: The methodology included: (i) dosing regimen selection and acquisition of pharmacokinetic data; (ii) microbiological data acquisition; and (iii) Monte Carlo simulation to estimate the PTA (probability of PK/PD target attainment) and CFR (cumulative fraction of response), as indicators of treatment success. RESULTS: At the current susceptibility breakpoints defined by EUCAST and CLSI for either cefuroxime axetil or cefixime, the probability of bactericidal target attainment is zero for the dosage regimens simulated. Considering the bactericidal target %fT>MIC>70%, the likelihood of the cefuroxime 500-mg q8h regimen or the cefixime 200-mg q12h regimen producing this exposure or achieving this target is only above 90% for organisms yielding MICs≤0.5mg/l and MICs≤0.25mg/l, respectively. Cefditoren pivoxil 400mg q12h provided probabilities of bactericidal target attainment of 80% or higher for MICs≤0.03mg/l, and ≤0.25mg/l if considering total instead of free drug concentrations. CONCLUSIONS: The results of the PK/PD target attainment analysis reveal that the likelihood of treatment success based upon the current breakpoints proposed by either EUCAST or CLSI is low. Of the three cephalosporins, cefixime 400mg q12h prove to be the best option in oral APN treatment, although this regimen is currently off label.

Ciprofloxacin resistance in nontypable Haemophilus influenzae clinical isolates / Resistencia a la ciprofloxacina en aislados clínicos de Haemophilus influenzae no tipificables

No disponible

Accuracy of the BD MAX™ vaginal panel in the diagnosis of infectious vaginitis.

The aim of this study was to evaluate the BD MAX™ vaginal panel in the diagnosis of bacterial vaginosis (BV), vulvovaginal candidiasis (VVC), and trichomoniasis by comparing it with conventional methods: (i) combination of Hay criteria and presence of clue cells with predominant growth of Gardnerella vaginalis, (ii) yeast culture, and (iii) combination of culture, wet mount microscopic examination, and an alternative molecular assay. One thousand vaginal samples of women ≥ 14 years were analyzed; 5% of the samples belonged to pregnant women. 19.3% were classified as BV, in 33.6% yeasts were recovered and in 1.5% TV was detected. For BV, sensitivity and specificity were of 89.8% and 96.5%, respectively; for VVC, sensitivity and specificity were of 97.4% and 96.8%, respectively, and for T. vaginalis, the sensitivity and specificity were of 100%. The BD MAX™ vaginal panel is highly sensitive and specific and simplifies the identification of infectious vaginitis.

Corioamnionitis y sepsis neonatal causada por Eikenella corrodens / Chorioamnionitis and neonatal septicaemia due to Eikenella corrodens

No disponible

Meningitis simultánea por neumococo y enterovirus en lactante / Simultaneous pneumococcal and enterovirus meningitis in an infant

No disponible

Correlación entre el sistema de MALDI-TOF Vitek-MSTM y los métodos convencionales de identificación de bacterias causantes de infección gastrointestinal / Correlation between MALDI-TOF Vitek-MSTM system and conventional identification methods of gastrointestinal infection causing bacteria

Introducción. La identificación rápida de patógenos es esencial para el diagnóstico de las infecciones gastrointestinales. La espectrometría de masas matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) ha demostrado ser eficaz y rápida en la identificación de microorganismos. El objetivo de este estudio fue evaluar la correlación entre Vitek-MSTM y los métodos convencionales para la identificación de bacterias causantes de infección gastrointestinal. Material y métodos. Se han identificado un total de 329 patógenos gastrointestinales empleando, simultáneamente, Vitek-MSTM (v2 SARAMIS MS-ID, BioMérieux, Marcy-I´Étoile, Francia) y métodos diagnósticos convencionales. En los casos de discrepancia se realizó secuenciación del gen 16SrRNA. Resultados. La correlación entre Vitek-MSTM y los métodos diagnósticos convencionales fue del 100% excepto para Yersinia enterocolitica (94,1%), Helicobacter pylori (10%) y Aeromonas veronii (0%). Conclusiones. Vitek-MSTM es un método rápido y útil en la identificación de bacterias enteropatógenas. Es necesario mejorar las prestaciones del sistema para H. pylori y A. veronii (AU)

Introduction. Rapid identification of pathogens is essential for the diagnosis of gastrointestinal infections. Matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry has shown to be effective and fast for the identification of microorganisms. The objective of this study was to evaluate the correlation between Vitek-MSTM and conventional methods for bacterial identification causing gastrointestinal infection. Material and methods. A total of 329 gastrointestinal pathogens were identified using Vitek-MSTM (v2 SARAMIS MS -ID, bioMérieux, Marcy-I´Étoile, France) and routine diagnostic methods simultaneously. In cases of discrepancy 16SrRNA gene sequencing was performed. Results. The correlation between Vitek-MSTM and diagnostic methods was 100% except for Yersinia enterocolitica (94.1%), Helicobacter pylori (10%) and Aeromonas veronii (0 %). Conclusions. Vitek-MSTM is a quick and useful method for identification of enterophatogenic bacteria. It is necessary to improve the performance of the system for the identification of H. pylori and A. veronii (AU)