Antibiograma rápido en Microbiología Clínica

Multi-drug-resistant Escherichia coli in adult male patients with enlarged prostate attending general hospitals in Benue state

The aim of this study was to investigate multi-drug-resistant (MDR) Escherichia coli in urine of adult male patients with enlarged prostate. Three hundred and sixty-eight samples of urine and blood were collected. Escherichia coli was isolated, purified, and identified and prostate-specific antigen (PSA) was determined. Multi-drug resistance test and specific drug resistance genes were assessed. Prevalence of Escherichia coli was high (38.5%) in patients with PSA of 60-79 ng ml-1 and 60% were MDR. The isolates showed highest resistance to tetracycline (53.3.0%) and least to cephalosporins (5%). They had intL and gyrA genes, which are integron, and quinolone resistance genes and sul1 and sul2 which are sulphonamide resistance-associated genes. Levofloxacin, ertapenem, and Augmentin (100% susceptibilities) were considered choice drugs for treatment of Escherichia coli infection in patients with elevated PSA.

Color-Coded Droplets and Microscopic Image Analysis for Multiplexed Antibiotic Susceptibility Testing

Since the discovery of antibiotics, the emergence of antibiotic resistance has become a global issue that is threatening society. In the era of antibiotic resistance, finding the proper antibiotics through antibiotic susceptibility testing (AST) is crucial in clinical settings. However, the current clinical process of AST based on the broth microdilution test has limitations on scalability to expand the number of antibiotics that are tested with various concentrations. Here, we used color-coded droplets to expand the multiplexing of AST regarding the kind and concentration of antibiotics. Color type and density differentiate the kind of antibiotics and concentration, respectively. Microscopic images of a large view field contain numbers of droplets with different testing conditions. Image processing analysis detects each droplet, decodes color codes, and measures the bacterial growth in the droplet. Testing E. coli ATCC 25922 with ampicillin, gentamicin, and tetracycline shows that the system can provide a robust and scalable platform for multiplexed AST. Furthermore, the system can be applied to various drug testing systems, which require several different testing conditions.

Microscopic Analysis of Bacterial Inoculum Effect Using Micropatterned Biochip

Antimicrobial resistance has become a major problem in public health and clinical environments. Against this background, antibiotic susceptibility testing (AST) has become necessary to cure diseases in an appropriate and timely manner as it indicates the necessary concentration of antibiotics. Recently, microfluidic based rapid AST methods using microscopic analysis have been shown to reduce the time needed for the determination of the proper antibiotics. However, owing to the inoculum effect, the accurate measurement of the minimal inhibitory concentration (MIC) is difficult. We tested four standard bacteria: Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Enterococcus faecalis, against five different antibiotics: piperacillin, cefotaxime, amikacin, levofloxacin, and ampicillin. The results showed that overall, the microfluidic system has a similar inoculum effect compared to the conventional AST method. However, due to the different testing conditions and determination protocols of the growth of the microfluidic based rapid AST, a few results are not identical to the conventional methods using optical density. This result suggests that microfluidic based rapid AST methods require further research on the inoculum effect for practical use in hospitals and can then be used for effective antibiotic prescriptions.

The incidence of antibiotic resistance within and beyond the agricultural ecosystem: A concern for public health

The agricultural ecosystem creates a platform for the development and dissemination of antimicrobial resistance, which is promoted by the indiscriminate use of antibiotics in the veterinary, agricultural, and medical sectors. This results in the selective pressure for the intrinsic and extrinsic development of the antimicrobial resistance phenomenon, especially within the aquaculture‐animal‐manure‐soil‐water‐plant nexus. The existence of antimicrobial resistance in the environment has been well documented in the literature. However, the possible transmission routes of antimicrobial agents, their resistance genes, and naturally selected antibiotic‐resistant bacteria within and between the various niches of the agricultural environment and humans remain poorly understood. This study, therefore, outlines an overview of the discovery and development of commonly used antibiotics; the timeline of resistance development; transmission routes of antimicrobial resistance in the agro‐ecosystem; detection methods of environmental antimicrobial resistance determinants; factors involved in the evolution and transmission of antibiotic resistance in the environment and the agro‐ecosystem; and possible ways to curtail the menace of antimicrobial resistance.

Preliminary readings of antimicrobial susceptibility panels: A simple, fast and inexpensive way to detect bacterial resistance and enhance antibiotic treatment of bloodstream infections

Increasing incidence of resistant bacteria needs faster identification (ID) and antibiotic susceptibility testing (AST) in order to improve antimicrobial treatment of severe infections. We propose a preliminary reading of the AST MicroScan® panels coupled with mass spectrometry ID. A total of 157 bacterial clinical isolates were processed for routine ID and AST (in 22 cases, ID and AST were performed directly from positive blood culture bottles). For gram-negatives, data from the initial and final readings were recorded and compared [89.9% category agreement (CA), 6.9% very major errors (VME)]. In adition all the 32 ESBL producers were detected at 5.3-8.6 hours. For Staphylococcus aureus, all the 16 MRSA isolates were detected at 4.5 to 7.5 hours. Thus, we find our preliminary readings approach as a simple, inexpensive and reliable way to detect and identify the most prevalent resistant bacteria in our institution on the same day that ID/AST is performed.

A two-hour antibiotic susceptibility test by ATP-bioluminescence

The antibiotic susceptibility test (AST) in Clinical Microbiology laboratories is still time-consuming, and most procedures take 24h to yield results. In this study, a rapid antimicrobial susceptibility test using ATP-bioluminescence has been developed. The design of method was performed using five ATCC collection strains of known susceptibility. This procedure was then validated against standard commercial methods on 10 strains of enterococci, 10 staphylococci, 10 non-fermenting gram negative bacilli, and 13 Enterobacteriaceae from patients. The agreement obtained in the sensitivity between the ATP-bioluminescence method and commercial methods (E-test, MicroScan and VITEK2) was 100%. In summary, the preliminary results obtained in this work show that the ATP-bioluminescence method could provide a fast and reliable AST in two hours.