Impact of the national shortage of polymyxin B in critically ill patients during the COVID-19 pandemic / Impacto da escassez nacional de polimixina B em pacientes gravemente enfermos durante a pandemia de COVID-19 / Impacto del desabasto nacional de polimixina B en pacientes críticos durante la pandemia de COVID-19

Background and Objectives: during the COVID-19 pandemic, the number of critical patients requiring intensive care increased considerably, resulting in an increase in infections due to multi-resistant microorganisms. In Brazil, in 2021, due to the high demand for polymyxin B use, there was a national shortage of the medication. One strategy used to overcome this situation was aminoglycoside use. The work aimed to analyze the impact of replacing polymyxin B with amikacin and gentamicin in the final stage of patients. Method: an analytical study with an observational, cross-sectional design, with a quantitative approach, through a retrospective analysis through the analysis of medical records, with the primary stages being discharges or deaths. Results: mortality was similar between the group treated with aminoglycoside and the group treated with polymyxin B. Within the aminoglycoside group, mortality was higher in the group that had bacteria resistant to the drug than in the group that had infection with an organism sensitive to this drug. Mortality was not affected by comorbidities, age, or number of hospital infections. The main factor that led to the need for dialysis was the combination of two nephrotoxic medications. Conclusion: two hypotheses emerged: the first would be that replacing polymyxin B with aminoglycosides did not impact mortality; the other would be that, regardless of the antibiotic group used, patients had a high risk of death. Despite sample limitations, the study corroborates the adoption of strategies for the rational use of antimicrobials.(AU)

Justificativa e Objetivos: durante a pandemia de COVID-19, o número de pacientes críticos que necessitaram de cuidados intensivos aumentou consideravelmente, resultando em aumento de infecções por microrganismos multirresistentes. No Brasil, em 2021, devido à grande demanda pelo uso da polimixina B, houve escassez nacional do medicamento. Uma estratégia utilizada para superar essa situação foi o uso de aminoglicosídeos. O trabalho teve como objetivo analisar o impacto da substituição da polimixina B por amicacina e gentamicina na fase final dos pacientes. Método: estudo analítico com desenho observacional, transversal, com abordagem quantitativa, por meio de análise retrospectiva por meio de análise de prontuários, sendo as etapas primárias as altas ou óbitos. Resultados: a mortalidade foi semelhante entre o grupo tratado com aminoglicosídeo e o grupo tratado com polimixina B. Dentro do grupo aminoglicosídeo, a mortalidade foi maior no grupo que apresentava bactérias resistentes ao medicamento do que no grupo que apresentava infecção por organismo sensível a este medicamento. medicamento. A mortalidade não foi afetada por comorbidades, idade ou número de infecções hospitalares. O principal fator que levou à necessidade de diálise foi a combinação de dois medicamentos nefrotóxicos. Conclusão: surgiram duas hipóteses: a primeira seria que a substituição da polimixina B por aminoglicosídeos não impactou a mortalidade; a outra seria que, independentemente do grupo de antibióticos utilizado, os pacientes apresentavam alto risco de morte. Apesar das limitações amostrais, o estudo corrobora a adoção de estratégias para o uso racional de antimicrobianos.(AU)

Antecedentes y Objetivos: durante la pandemia de COVID-19, el número de pacientes críticos que requirieron cuidados intensivos aumentó considerablemente, resultando en un aumento de infecciones por microorganismos multirresistentes. En Brasil, en 2021, debido a la alta demanda del uso de polimixina B, hubo escasez nacional del medicamento. Una estrategia utilizada para superar esta situación fue el uso de aminoglucósidos. El trabajo tuvo como objetivo analizar el impacto de la sustitución de la polimixina B por amikacina y gentamicina en la etapa final de los pacientes. Método: estudio analítico con diseño observacional, transversal, con enfoque cuantitativo, mediante un análisis retrospectivo mediante el análisis de historias clínicas, siendo las etapas primarias las altas o defunciones. Resultados: la mortalidad fue similar entre el grupo tratado con aminoglucósido y el grupo tratado con polimixina B. Dentro del grupo de aminoglucósido, la mortalidad fue mayor en el grupo que tenía bacterias resistentes al fármaco que en el grupo que tenía infección con un organismo sensible a este. droga. La mortalidad no se vio afectada por las comorbilidades, la edad o el número de infecciones hospitalarias. El principal factor que llevó a la necesidad de diálisis fue la combinación de dos medicamentos nefrotóxicos. Conclusión: surgieron dos hipótesis: la primera sería que la sustitución de polimixina B por aminoglucósidos no impactó la mortalidad; la otra sería que, independientemente del grupo de antibióticos utilizado, los pacientes tenían un alto riesgo de muerte. A pesar de las limitaciones de la muestra, el estudio corrobora la adopción de estrategias para el uso racional de antimicrobianos.(AU)

Comparative application of biological and ninhydrin- derivatized spectrophotometric assays in the evaluation and validation of amikacin sulfate injection

Abstract Instrumental techniques are preferred over bioassay methods for antibiotic quantification mainly due to speed and ability to quantify metabolites in biological samples; however, the potency and biological activity of these drugs cannot be assessed. Two methods - agar well diffusion (bio-assay) and spectrophotometric methods were used to evaluate amikacin sulfate injection. Agar plates were inoculated with S. aureus inoculum; zones of inhibition from its susceptibility to amikacin were obtained, while spectrophotometric absorption at 650 nm of ninhydrin- derivatized amikacin in phosphate buffer (pH 8) was measured. Methods performance showed linearity from 1 - 16 µgmL-1 (bioassay, r = 0.9994) and 10-50 µgmL-1 (spectrophotometric, r = 0.9998). Molar absorptivity was 2.595 x 104 Lmol-1cm-1. Limits of detection and quantification were 1.07 and 3.24 µgmL-1 respectively for bioassay method, while corresponding values for spectrophotometric method were 0.98 and 2.97 µg mL-1. Relative standard deviations were ≤ 2.0% for both methods, with recoveries from 95.93 - 100.25%. Amikacin in brands ranged from 97.53 ± 2.68 to 100.84 ± 1.82%, student's t-test was ≤ 2.78 (n = 4) with respect to label claim for both methods. Experimental paired t-test (t = 2.07; n = 4) and F-test (F = 3.94; n = 4) values indicated no significant difference between both methods, hence comparable and can jointly be used in quality control assessment of antibiotics

Resistencia enzimática en Pseudomonas aeruginosa, aspectos clínicos y de laboratorio / Enzymatic resistance in Pseudomonas aeruginosa, clinical and laboratory aspects

Resumen Pseudomonas aeruginosa es uno de los principales patógenos que causa infecciones asociadas a la atención en salud (IAAS). Su capacidad de adaptación, diseminación, resistencia intrínseca a los antimicrobianos y de adquirir nuevos mecanismos a través de elementos genéticos móviles, hacen que el tratamiento de las infecciones por este microorganismo sea un desafío para el médico clínico. Intrínsecamente, P. aeruginosa, presenta una reducida permeabilidad en la membrana externa, debido a la expresión de bombas de expulsión, y una cefalosporinasa tipo AmpC inducible. Además, P. aeruginosa es capaz de adquirir nuevos determinantes de resistencia por transferencia horizontal en forma de casetes situados en integrones, y a su vez, localizados en transposones o plásmidos. Dentro de la resistencia enzimática que presenta P. aeruginosa destacan las β-lactamasas, incluyendo aquellas de espectro extendido (BLEE) y las carbapenemasas. Pero también enzimas modificadoras de los aminoglucósidos, haciendo que este microorganismo pueda presentar fenotipos de multi-resistencia (MDR), resistencia extrema (XDR) y panresistencia (PDR) a los antimicrobianos denominados antipseudomonas, incluyendo a las nuevas cefalosporinas con inhibidores de beta-lactamasas.

Abstract Pseudomonas aeruginosa is one of the major pathogens causing healthcare-associated infections (HAI). Its capacity of adaptation, dissemination, intrinsic resistance to antimicrobials and of acquiring new mechanisms through mobile genetic elements, make the treatment of infections by this microorganism a challenge for the clinician. Intrinsically, P. aeruginosa, presents a reduced permeability in the external membrane, due to the expression of efflux pumps, and an inducible AmpC-type cephalosporinase. In addition, P. aeruginosa is able to acquire new resistance determinants by horizontal transfer in the form of cassettes located in integrons, and in turn located in transposons or plasmids. Within the enzymatic resistance that P. aeruginosa presents, betalactamases, including extended spectrum (ESBL) and carbapenemases. But also aminoglycoside modifying enzymes, stand out, causing this microorganism to present multi-resistance phenotypes (MDR), extreme resistance (XDR) and pan-resistance (PDR) to the called antipseudomonal antibiotics, including the new cephalosporins with betalactamase inhibitors.

Antimicrobianos en neonatología. Parte I: Recomendaciones de dosificaciones basadas, en la más reciente evidencia en recién nacidos Comité Consultivo de Infecciones Neonatales, Sociedad Chilena de Infectología / Antibiotics in neonatology. Part I: Dosage recommendations based on the most recent evidence in newborns Advisory Committee on Neonatal Infections, Chilean Society of Infectious Diseases

Resumen Los antimicrobianos son los medicamentos más utilizados en los neonatos durante su primer mes de vida cuando se encuentran en unidades neonatales, principalmente por el alto riesgo que presentan de adquirir infecciones graves como la sepsis. La mayoría de estos antimicrobianos se utilizan con dosis extrapoladas en base a las recomendaciones en población adulta y niños mayores, a pesar de que la fisiopatología en los recién nacidos es absolutamente diferente. Lo anterior lleva a un mayor riesgo a que ocurran más efectos adversos los que pueden conducir a una mayor toxicidad y a fallas terapéuticas, entre otros. En la última década se han realizado mayores estudios farmacocinéticos de antimicrobianos en neonatos; esta reciente evidencia ha permitido nuevas recomendaciones de dosificación considerando el peso y la edad gestacional del recién nacido, entre otras variables, de acuerdo al antimicrobiano estudiado. En base a una mayor evidencia sobre el comportamiento farmacocinético de los antimicrobianos en neonatos, se ha elaborado este documento para así facilitar y promover su correcto uso en las unidades neonatales.

Abstract Antibiotics are the most widely used medications in neonates during their first month of life in neonatal units, mainly due to the high risk they present of acquiring serious infections such as sepsis. Most of these antibiotics are used with extrapolated doses based on the suggestions in the adult population and older children, despite the fact that the pathophysiology in newborns is absolutely different. This leads to a higher risk of more adverse effects occurring, which can lead to greater toxicity and therapeutic failures, among others. In the last decade more and more pharmacokinetic studies of antibiotics have been carried out in neonates, this recent evidence has led to new dosage recommendations taking into account the weight and gestational age of the newborn, among other variables, in agreement to the antibiotic studied. Therefore, based on the need to order and summarize the most up-to-date and most evidence-based information on antibiotics in neonates, this document was prepared to facilitate and promote its correct use in neonatal units.

A study of effect of aminoglycoside therapy on auditory brainstem evoked responses in preterm and term neonates

Background: Aminoglycosides are widely used drugs in neonates with associated ototoxic side effects, that can be diagnosed with auditory brainstem evoked responses, which is the recommended screening technique in neonatal intensive care unit infants.  This study was conducted to evaluate the effect of aminoglycoside therapy on auditory brainstem evoked responses in term and preterm neonates.Methods: A cross-sectional case control study. Two groups of 26 term and 22 preterm neonates who received aminoglycosides, with no other known risk factors for ototoxicity, were compared with suitable matched control group of 10 neonates in each. ABER was done after at least 5 days of aminoglycoside therapy and results were compared to suitable matched controls.Results: Mean latency of wave I in term neonates at 90 dB and 60 dB and mean interwave latencies of I-V waves in preterm neonates at 30 dB was higher in study group and statistically significant. No statistically significant difference in any of ABER parameters was observed in any group, at all other intensities.Conclusions: Wave I latency was prolonged in study group of term neonates at two intensities which indicates effect of aminoglycoside therapy on distal portion of acoustic nerve. But as there were no such findings at other intensities in term study group and in preterm study group and moreover no other ABER abnormalities were observed, it was concluded that the aminoglycoside therapy has low potential for ototoxicity. Authors support the ABER screening for early detection of hearing abnormalities, and recommend study on larger group of neonates and meta-analysis for final conclusion for evidence-based recommendations to use aminoglycosides in neonates, in view of audiometric and neurological abnormalities.

Analytical Methods For The Determination Of Aminoglycosides Antibiotics By Chromatrographic Technique

Aminoglycosides antibiotics are considered to be the antimicrobial agents used frequently in the treatment of human diseases caused by a bacterial infection. Most of the aminoglycosides antibiotics are highly polar in nature and they are lacking the UV absorbing chromophore in the molecules. The present articles accentuate the analytical method associated with the analysis of aminoglycosides molecules. Various chromatographic techniques like liquid chromatography, gas chromatography; mass spectrometry were used for the detection of aminoglycosides antibiotics. However, due to its limitation in the ultraviolet-visible spectrophotometry (UV/Vis) technique, different types of detection techniques like corona-charged aerosol detector (CAD), electrochemical detector (ECD) were used as a most powerful and versatile technique for the demonstration of these molecules in the analytical field. Analytical methods help to ensure the quality of the drug products. This review paper is devoted to providing an overview of the key performance technique used for the application and detection of these aminoglycosides molecules.

Diagnóstico e tratamento da síndrome do choque tóxico estreptocócico em unidade de terapia intensiva pediátrica: relato de caso / Diagnosis and treatment of streptococcal toxic shock syndrome in the pediatric intensive care unit: a case report

RESUMO Dentre as infecções causadas por Streptococcus β hemolyticus do grupo A de Lancefield, talvez a síndrome do choque tóxico seja a mais grave, com alto índice de mortalidade. A semelhança clínica com outras formas de choque, principalmente séptico, pode, muitas vezes, confundir o avaliador e interferir na escolha da terapêutica mais adequada. Esse relato tem o objetivo de auxiliar seus leitores quanto à necessidade de adicionar tal síndrome como diagnóstico diferencial, frente a quadros de choque, principalmente aqueles que não apresentam manifestações clínicas bem definidas. Para isso, apresentamos o quadro de um lactente com sintomas gripais comuns, que evoluiu rapidamente com exantema, rebaixamento do nível de consciência, sinais clínicos e laboratoriais de choque, com necessidade de suporte intensivo. Além de culturas indicando o agente etiológico, o aparecimento de exantema e fasciíte necrosante levou ao diagnóstico, mas, em menos de 50% dos casos temos sinais clínicos clássicos dessa entidade. As penicilinas em terapia combinada com aminoglicosídeos ainda são a terapia de escolha e possuem alto nível de evidência. Apesar da gravidade a evolução foi satisfatória.

ABSTRACT Among the infections caused by Streptococcus β hemolyticus from the Lancefield serogroup A, toxic shock syndrome is perhaps the most severe, and its mortality rate is high. Its clinical similarity to other forms of shock, especially septic shock, can often confuse the evaluator and interfere with the selection of the most appropriate therapy. This report aims to inform readers of the need to add this syndrome as a differential diagnosis in cases of shock, especially those with no well-defined clinical manifestations. For this purpose, we present the case of an infant with common flu-like symptoms who progressed rapidly with a rash, a reduced level of consciousness and clinical and laboratory signs of shock that required intensive support. In addition to cultures indicating the etiological agent, the appearance of exanthema and necrotizing fasciitis led to the diagnosis. However, less than 50% of cases present classic clinical signs of this entity. Penicillins combined with aminoglycosides are still the therapy of choice and are supported by a high level of evidence. Despite the severity of this patient's presentation, the progression was satisfactory.

Challenges in the development of analytical test procedure for aminoglycosides: A critical review

The present article reviews the challenges and hurdles in the development of an analytical method for aminoglycosides(AG). The article emphasizes on the attempts made to develop analytical methods based on HPLC and othersophisticated techniques, such as LC-MS, radioimmunoassay, microbial assay, enzyme linked immunosorbentassay (ELISA), extractive colorimetry, anion-exchange chromatography with pulsed amperometric detection, highperformance thin layer chromatography, densitometry, and microbial agar diffusion assay. The various media mostlyused for the in vitro as well as in vivo estimation of AG by HPLC and LC-MS are heptafluorobutyric acid, ammoniumacetate, ammonium formate and formic acid. Estimation of AG by radioimmunoassay and ELISA can be suitably doneby using TRIS-HCl and saline phosphate buffer. The buffer media used for ex vivo analysis mostly include MEM,TRIS and saline phosphate. The presence of AG in food from the animal sources, water bodies, and its prolongedexposure may result in serious health issues. The present article outlined the various sensitive, robust and preciseanalytical techniques for the estimation of the various aminoglycosides in many sources, and discussed the hurdlesfaced during the development of the analytical techniques.

Broad spectrum antibiotic use among in-patients at a hospital in Nairobi, Kenya

Background: Antimicrobial resistance is an increasingly serious threat to global public health. While the use of antibiotics is an important contributing factor, there are gaps regarding this in our region. This study aimed to describe the use of nine broad spectrum antibiotics among in-patients of The Nairobi Hospital (TNH) so as to identify opportunities for quality improvement.Methods: This was a retrospective review of the use of meropenem, ertapenem, imipenem, cefepime, piperacillin, gentamicin, amikacin, vancomycin and teicoplanin among in-patients of TNH from 1st January 2018 to 31st March 2018. Demographic and clinical data of all in-patients who were prescribed these antibiotics during the study period were retrieved from patient files.Results: There were 301 study participants with a median age (range) of 30years (1day-74years), of whom 161 (53.5%) were male. More than half of the participants were admitted for less than one week and had at least one co-morbidity. Meropenem was the most commonly prescribed study antibiotic 123 (40.9%) followed by amikacin 89 (29.6%). Respiratory tract infections 125 (41.5%) were the predominant indications. Meropenem had the longest mean duration of administration, 6.5days while the aminoglycosides were administered for a relatively shorter duration of about 4.8days. Cultures were done on 187 (62.1%) patients though it is only samples of 45 patients that grew an organism, E. coli and Klebsiella sp being the most frequently isolated organisms.Conclusions: There’s a need to strongly intensify implementation of restriction strategies for Meropenem use and introduction of education programs on antimicrobial stewardship targeting all prescribers.

Evaluation of Nephroprotective Effect of Ethanolic Extract of Leaves of Aloe barbadensis against Gentamicin Induced Nephrotoxicity in Rats

Background: To evaluate the nephroprotective effect of ethanolic extract of leaves of Aloe barbadensis against gentamicin induced nephrotoxicity in albino rats. Methods: In the present study 24 albino rats of 120-150gm were taken and these rats were divided into four groups. Group I and II served as vehicle control and negative control groups respectively. While group III (EEAB150) and IV (EEAB300) served as treatment groups, which were treated with 150 and 300mg/kg/day of ethanolic extract of Aloe barbadensis, 1 hour before each dose of gentamicin administration for 8 days. On the 8th day of Gentamicin administration (80mg/kg/day, i.p) blood samples for BUN, serum creatinine, urine creatinine and total protein were taken while the rat kidneys for antioxidant assay and histology were obtained. Results: In group II nephrotoxicity was confirmed by significant elevation of BUN and Serum creatinine while urine creatinine and total protein is significantly decreased compared to group I , while in treatment groups III and IV there is significant attenuation of elevated BUN and S. creatinine while urine creatinine and total protein tends to increase compared to group II. Also, there was significant changes observed in antioxidant markers in the treatment groups III and IV. Improvement in renal function was also confirmed by histology of rat kidneys. Conclusion: Ethanolic extracts of leaves of Aloe barbadensis possess nephroprotective effect against gentamicin induced nephrotoxicity.

Sequential analysis as a tool for detection of amikacin ototoxicity in the treatment of multidrug-resistant tuberculosis / Análise sequencial como ferramenta na detecção da ototoxicidade da amicacina no tratamento da tuberculose multirresistente

ABSTRACT Objective: To investigate early detection of amikacin-induced ototoxicity in a population treated for multidrug-resistant tuberculosis (MDR-TB), by means of three different tests: pure-tone audiometry (PTA); high-frequency audiometry (HFA); and distortion-product otoacoustic emission (DPOAE) testing. Methods: This was a longitudinal prospective cohort study involving patients aged 18-69 years with a diagnosis of MDR-TB who had to receive amikacin for six months as part of their antituberculosis drug regimen for the first time. Hearing was assessed before treatment initiation and at two and six months after treatment initiation. Sequential statistics were used to analyze the results. Results: We included 61 patients, but the final population consisted of 10 patients (7 men and 3 women) because of sequential analysis. Comparison of the test results obtained at two and six months after treatment initiation with those obtained at baseline revealed that HFA at two months and PTA at six months detected hearing threshold shifts consistent with ototoxicity. However, DPOAE testing did not detect such shifts. Conclusions: The statistical method used in this study makes it possible to conclude that, over the six-month period, amikacin-associated hearing threshold shifts were detected by HFA and PTA, and that DPOAE testing was not efficient in detecting such shifts.

RESUMO Objetivo: Verificar a detecção precoce de ototoxicidade causada pelo uso de amicacina numa população tratada para tuberculose multirresistente (TBMR) por meio da realização de três testes distintos: audiometria tonal liminar (ATL), audiometria de altas frequências (AAF) e pesquisa de emissões otoacústicas por produto de distorção (EOAPD). Métodos: Estudo longitudinal de coorte prospectiva incluindo pacientes de ambos os sexos, com idade entre 18 e 69 anos, com diagnóstico de TBMR pulmonar e que necessitaram utilizar amicacina por seis meses em seu esquema medicamentoso antituberculose pela primeira vez. A avaliação auditiva foi realizada antes do início do tratamento e depois de dois e seis meses do início do tratamento. A análise dos resultados foi realizada por meio de análise estatística sequencial. Resultados: Foram incluídos 61 pacientes, mas a população final foi constituída de 10 pacientes (7 homens e 3 mulheres), em razão da análise sequencial. Ao se comparar os valores das respostas dos testes com aqueles encontrados na avaliação basal, foram verificadas mudanças nos limiares auditivos compatíveis com ototoxicidade após dois meses de tratamento através da AAF e após seis meses de tratamento através da ATL. Entretanto, essas mudanças não foram verificadas através da pesquisa de EOAPD. Conclusões: Ao se considerar o método estatístico utilizado nessa população, é possível concluir que mudanças nos limiares auditivos foram associadas ao uso da amicacina no período de seis meses por meio de AAF e ATL e que a pesquisa de EOAPD não se mostrou eficiente na identificação dessas mudanças.

High-level aminoglycoside resistance in Acinetobacter baumannii recovered from Intensive Care Unit patients in Northeastern India

Background: Acinetobacter baumannii has emerged as an important nosocomial pathogen, its ability to acquire resistance to carbapenems and aminoglycosides, has complicated their treatment regimen. The present study investigates the prevalence and diversity of aminoglycoside-modifying enzymes and 16S methyltransferases in A. baumannii isolates recovered from patients admitted in Intensive Care Unit (ICU) of a tertiary referral hospital in Northeastern India. Materials and Methods: We investigated the high-level aminoglycoside-resistance (HLAR) (gentamicin and amikacin minimum inhibitory concentration ? 512 ?g/ml) among 164 multidrug-resistant A. baumannii obtained from ICU. Genes encoding aminoglycoside-modifying enzymes, 16S methyltransferase and coexisting beta-lactamases were amplified. Horizontal transferability, plasmid stability and elimination assays were performed. Clonality and sequence types were evaluated by repetitive extragenic palindromic-polymerase chain reaction and multilocus sequence typing (MLST) respectively. Results: A total of 130 (79.2%) isolates were found to exhibit HLAR, with acquired aminoglycoside-resistance genes in 109 (83.8%) isolates along with coexisting extended-spectrum beta-lactamases and metallo-beta-lactamases. Genes aph (3') I, aph (3') VIa and armA were predominant and horizontally transferable. Plasmids were eliminated with single sodium dodecyl sulphate treatment. Seventeen haplotypes were found responsible for the infection. MLST revealed circulation of ST583 and ST188 in ICU. Conclusions: This study reveals the presence of aminoglycoside-resistance genes in combination with blaCTXM and blaNDM, which are highly stable and not frequently reported from this geographical region. Further, the study could predict limited treatment option and need for formulating infection control strategy.

Characterisation of plasmid-mediated rmtB-1 in Enterobacteriaceae clinical isolates from São Paulo, Brazil

OBJECTIVES The emergence of 16S rRNA methyltranferases (16 RMTAses) has jeopardised the clinical use of aminoglycosides. RmtB is one of the most frequently reported in Gram-negatives worldwide. In this study, we aimed to estimate the frequency of 16S RMTAses encoding genes in Enterobacteriaceae isolated in a three-month period from a tertiary Brazilian hospital. METHODS All Gram-negatives classified as resistant to amikacin, gentamicin, and tobramycin by agar screening were selected for analysis. The presence of 16SRMTases encoding genes was verified by polymerase chain reaction (PCR). Antimicrobial susceptible profile was determined by broth microdilution. The genetic relationship among these isolates was accessed by pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Selected RmtB-producing isolates were characterised by whole genome sequencing (WGS) analysis. RESULTS Twenty-two of 1,052 (2.1%) Enterobacteriaceae were detected as producers of RmtB-1 [Klebsiella pneumoniae (n = 21) and Proteus mirabilis (n = 1)]. blaKPC-2 was identified among 20 RmtB-1-producing K. pneumoniae isolates that exhibited an identical PFGE and MLST (ST258) patterns. Two K. pneumoniae isolates, the A64216 (not harboring bla KPC-2), A64477 (harboring bla KPC-2) and one P. mirabilis isolate (A64421) were selected for WGS. rmtB-1 and bla KPC-2 genes were carried by distinct plasmids. While a plasmid belonging to the IncFIIk group harbored rmtB-1 in K. pneumoniae, this gene was carried by a non-typable plasmid in P. mirabilis. In the three analysed plasmids, rmtB-1 was inserted on a transposon, downstream a Tn2. CONCLUSION Our findings suggested that the rmtB-1 was harbored by plasmids distinct from those previously reported in Bolivia and China. It suggests that multiple mobilization events might have occurred in South America.

Determination of 11Kinds of Aminoglycosides in Aquatic Products by Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry with Molecularly Imprinted Polymers Solid Phase Extraction / 分析化学

An ultra performance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS) method was developed for the determination of 11 kinds of aminoglycosides (AGs), including paromomycin, spectinomycin, tobramycin, gentamycin, kanamycin, hygromycin B, apramycin, streptomycin, dihydrostreptomycin,amikacin and neomycin in aquatic products. Samples were extracted by phosphate buffer solution, and purified on molecularly imprinted polymers (MIP) solid phase extraction column. After separated by Obelisc R chromatographic column, AGs were detected by UPLC-MS/MS. It showed a good linearity relationship in the AGs concentration range of 1.0-1000 ng/mL with the correlation coefficient R2>0.994. The limit of detection (LOD,S/N≥3) was ranged from 1.0 μg/kg to 10.0 μg/kg,and the limit of quantitation (LOQ,S/N≥10) was ranged from 2.0 μg/kg to 20.0 μg/kg. Besides, the average recoveries presented 78.4%-109.6% with the relative standard deviation (RSD, n=6) of 2.3%-14.9%. This method was successfully applied to the simultaneous determination of 11 kinds of AGs with high sensitivity in aquatic products.

Aminoglycoside resistance genes in carbapenem-resistant Klebsiella pneumoniae / 中华临床感染病杂志

Objective To analyze the aminoglycoside ( AG ) antibiotics resistance rate of carbapenem-resistant Klebsiella pneumoniae ( CRKP ) and its molecular mechanisms.Methods One hundred and four strains of CRKP isolated from 4 hospitals in Zhejiang Province from January 2013 to June 2014 were collected, including 56 strains from Sir Run Run Shaw Hospital , Zhejiang University School of Medicine ( S hospital ), 22 from the First Affiliated Hospital, Zhejiang University School of Medicine ( Z hospital), 13 from Yiwu TCM Hospitals (Y Hospital) and 13 from Fuyang First People's Hospital (F Hospital).VITEK 2 Compact method and K-B disk method were used to detect the susceptibility of commonly used antibiotics including three kinds of AGs (kanamycin, gentamycin and amikacin ).PCR and sequencing techniques were used to screen the aminoglycoside resistance -related 16S rRNA methylation genes (rmtA, rmtB and armA) and the aminoglycoside modified enzyme resistance gene [aac(6′)Ⅰb].The relationship between drug resistance and carrier status of drug resistance genes was analyzed .Homologous analysis of rmtB-positive strains was performed using PFGE to examine the epidemic spread of strains in each hospital.Results All 104 CRKP strains were multi-drug resistant and had high resistance to cephalosporins, fluoroquinolones ( ciprofloxacin, levofloxacin ) and nitrofurantoin.The resistance rates to gentamicin, kanamycin and amikacin were 73.1%(76/104), 64.4%(67/104) and 56.7%(59/104), respectively.The carrying rates of aminoglycoside-resistance genes were: rmtB 56.7%( 59/104 ), aac (6′)Ⅰb 17.3%(18/104), armA 1.9%(2/104); while no rmtA was detected.Thirty-seven strains did not carry the screened genes.Amikacin-resistant strains were resistant to both kanamycin and gentamicin, and both were rmtB-positive strains.The PFGE classification results showed that 104 strains were divided into 11 clonal populations, and there were scattered non-population clones in each hospital. There were seven major clonal populations (Ⅰ-Ⅶ) carrying rmtB genes, of which typeⅠ, typeⅢand typeⅤwere prevalent in S hospital ; typeⅡ, typeⅥand TypeⅦwere popular in Z hospital ; the distribution of strains in Y hospital was scattered ; F hospital had one independent clone type Ⅳ(3 strains).Conclusion AGs still have certain sensitivity to CRKP strains.The main mechanism of strain resistance to AGs is the rmtB gene-mediated 16S rRNA methylase.

Reflection and Outlook on the Current Analytical Methods for Aminoglycosides / 中国药师

The determination methods for the related substances and contents of aminoglycosides were reviewed. The HPLC-ELSD, HPLC-PAD and the other methods for the determination of aminoglycosides in Chinese Pharmacopoeia, USP and European Pharmacopoeia were introduced. The utilization specialties of the post column derivatization in detecting aminoglycosides were also in-troduced. Finally, the above three methods were compared, and the development of analytical methods for aminoglycosides was out-looked.

Factores asociados a coagulopatías adquiridas en una unidad de cuidados intensivos / Factors Associated with Acquired Coagulopathies in an Intensive Care Unit

Introducción: en los pacientes críticos existe un desequilibrio entre las actividades procoagulantes y las anticoagulantes, por ello las alteraciones de la coagulación o coagulopatías son una complicación frecuente que se asocia con una elevada morbilidad y mortalidad. Objetivos: identificar factores de riesgo asociados con coagulopatías adquiridas en pacientes ingresados y analizar la relación entre coagulopatía y mortalidad. Métodos: se realizó un estudio longitudinal prospectivo, donde se revisaron complementarios e historias clínicas de 29 pacientes ingresados en la unidad de cuidados intensivos del hospital Hermanos Ameijeiras, desde abril hasta junio de 2011. Se identificaron factores de riesgo asociados a las coagulopatías y se analizó su relación con la mortalidad. Resultados: se identificó la presencia de coagulopatías al ingreso en 58,62 por ciento, entre las 48-72 h 44,82 por ciento y en la última evaluación 51,73 por ciento. Predominó la coagulopatía por deficiencia de factores dependientes de vitamina K. Dentro de la unidad, el uso de hemocomponentes y la administración de aminoglucósidos resultaron estadísticamente significativos. Fallecieron 21 de los pacientes y en 13 de ellos se detectó la presencia de coagulopatía representando 44,8 por ciento. Conclusiones: se detectó que es dos veces más probable que a la persona que le administren hemocomponentes desarrolle algún tipo de coagulopatía y 5 veces más probable si se le administran aminoglucósidos. No se encontró relación significativa entre la presencia de coagulopatía y mortalidad, ni relación significativa entre la presencia de sangramiento y mortalidad(AU)

Introduction: There is an imbalance between procoagulant activities and anticoagulants in critical patients, so coagulation disorders or coagulopathies are a frequent complication associated with high morbidity and mortality. Objectives: To identify risk factors associated with acquired coagulopathies in hospitalized patients and to analyze the relationship between coagulopathy and mortality. Methods: A prospective longitudinal study was carried out. Complementary and clinical histories of 29 patients were reviewed. These patients had been admitted to the intensive care unit at Hermanos Ameijeiras hospital from April to June 2011. Risk factors associated with coagulopathies were identified. Mortality relationship was analyzed. Results: The presence of coagulopathies on admission was identified in 58.62 percent, 44.82 percent in 48-72 h and 51.73 percent in last assessment. Coagulopathy was predominant due to deficiency of vitamin K dependent factors. The use of blood components and the administration of aminoglycosides were statistically significant in the unit. Twenty one (21) patients died and thirteen (13) coagulopathy was detected, (44.8 percent). Conclusions: It was detected that it is twice as likely that the person receiving hemocomponents will develop some type of coagulopathy and five times more likely if they are administered aminoglycosides. No significant relationship was found between the presence of coagulopathy and mortality, nor significant relationship between the presence of bleeding and mortality(AU)

Problemas relacionados a medicamentos antimicrobianos em unidade de terapia intensiva neonatal / Antimicrobial drug-related problems in a neonatal intensive care unit

RESUMO Objetivo: Determinar os principais problemas relacionados a medicamentos em neonatos sob uso de antimicrobianos. Métodos: Estudo observacional, prospectivo e longitudinal. Os problemas relacionados a medicamentos foram classificados de acordo com a versão 6.2 da Pharmaceutical Care Network Europe Foundation. Foi executada análise descritiva, na qual as variáveis clínicas e terapêuticas foram apresentadas por frequências absolutas e relativas, ou por média e desvio padrão, conforme apropriado. Resultados: Foram incluídos 152 neonatos com predomínio do sexo masculino (58,5%), idade gestacional de 32,7 ± 4,2 semanas e peso de 1.903,1 ± 846,9g. A principal hipótese diagnóstica de infecção foi a sepse precoce (66,5%), detectando-se que 71,7% dos neonatos apresentavam algum fator de risco para infecção. Dentre os neonatos, 33,6% apresentaram pelo menos um problema relacionado a medicamento. Destes, 84,8% estavam relacionados à efetividade do tratamento e 15,2% a reações adversas. A principal causa de problemas relacionados a medicamentos foi a escolha da dose, sobretudo dos aminoglicosídeos e das cefalosporinas. Conclusão: O uso de antimicrobianos em terapia intensiva neonatal relaciona-se principalmente a problemas relacionados a medicamentos de efetividade, predominando a prescrição de antimicrobianos em subdose, sobretudo os aminoglicosídeos.

ABSTRACT Objective: The goal was to determine the main drug-related problems in neonates who were using antimicrobials. Method: This was an observational, prospective and longitudinal study. Drug-related problems were classified according to version 6.2 of the Pharmaceutical Care Network Europe Foundation classification. A descriptive analysis was performed, in which the clinical and therapeutic variables were presented as absolute and relative frequencies or as the mean and standard deviation, as appropriate. Results: In total, 152 neonates with a predominance of males (58.5%), gestational age of 32.7 ± 4.2 weeks and weight of 1,903.1 ± 846.9g were included. The main diagnostic hypothesis of infection was early sepsis (66.5%), and 71.7% of the neonates had some risk factor for infection. Among the neonates, 33.6% had at least one drug-related problem. Of these, 84.8% were related to treatment effectiveness and 15.2% to adverse reactions. The main cause of drug-related problems was the selected dose, particularly for aminoglycosides and cephalosporins. Conclusion: The use of antimicrobials in the neonatal intensive care is mainly associated with problems related to medication effectiveness, predominantly the prescription of subdoses of antimicrobials, especially aminoglycosides.

Modification factors associated with maternally inherited non-syndromic hearing loss / 中华耳鼻咽喉头颈外科杂志

Mutations in the mitochondrial DNA have been certified to be one of the most important causes of maternally inherited sensorineural hearing loss. Among these, mitochondrial 12S rRNA1555A>G, 1494C>T and other mutations are associated with both nonsyndromic and drug induced hearing loss caused by aminoglycosides. Individuals carrying 1555A>G or 1494C>T mutation have a variety of clinical manifestations, which implies that the 1555A>G or 1494C>T mutation is a chief factor underlying the development of deafness but insufficient to produce the clinical phenotype. Therefore other modifier factors, such as aminoglycosides, mitochondrial haplotypes, secondary mutation or nuclear modifier genes, may play an important role in the phenotypic expression of the deafness-associated mitochondrial 12S rRNA1555A>G or 1494C>T mutation. In this review, the modifier factors for the phenotypic expression of deafness-associated mitochondrial 12S rRNA1555A>G or 1494C>T mutations were summarized and proposed the pathogenesis of maternally inherited deafness.

Aminoglycoside resistance genes of Acinetobacter baumannii / 中国人兽共患病学报

To investigate the distribution of the resistance genes of Acinetobacter baumannii to aminoglycoside,48 strains of extensively drug resistant Acinetobacter baumannii were collected from the First Affiliated Hospital of Bengbu Medical College from January to December,2015.The drug sensitivity test and identification were performed by VITEK 2 compact automatic microorganism instrument.Twelve aminoglycosides modifying enzymes,three 16SrRNA methylase genes and efflux pump abeB gene were detected from these isolates by PCR.Results showed that among these experimental 16 genes,aac(6')-Ⅰb gene was detected from 19 of 48 isolates (39.6％),both armA and adeB genes were 43 (89.6％),ant(3")-Ⅰa gene was from 5 (10.4％),while the other genes were not found.And more than two gene types were amplified from 39 of 48 strains (81.3％).In conclusion,the aac(6')-Ⅰb,armA gene and efflux pump adeB may play a key role in drug resistance to aminoglycosides antibiot ics of Acinetobacter Baumanni in our hospital.