Aerobic Gram-negative Bacteria Research Articles

Rare case of resistant Achromobacter xylosoxidans-associated meningitis due to intrathecal catheter

Background: Achromobacter xylosoxidans (AX) is an aerobic Gram-negative opportunistic bacteria known to inhabit various environments and is most commonly associated with nosocomial infections in immune-compromised patients. Although rare, AX can cause a variety of neurological infections, such as meningitis, ventriculitis, and osteomyelitis. Intravascular catheters, intrathecal pumps, and contaminated surgical instruments are potential vectors for such patients. Case Description: Here, we present a unique case of multidrug-resistant AX-positive meningitis secondary to infection of a nonfunctional intrathecal narcotic pump. The patient has a complex past medical history leading up to infection, and care was significantly compromised by homelessness and inflammatory bowel disease (IBD). Treatment included catheter removal and antibiotics. Conclusion: Patients who suffer from homelessness or IBD show a possible increased risk of this infection. This case emphasizes the need for increased care regarding these patients, along with describing the complications and timeline when treating this rare type of meningitis.

Study of Aerobic Bacteria from Surgical Site Infection and their Antibiotic Susceptibility Pattern at a Tertiary Care Centre in Eastern Nepal

Background: The surgical site infections are the third most common nosocomial infection. The most common organism is Staphylococcus aureus. Nepal has a 4-7% overall prevalence rate for surgical site infection. The study objective was to find out the aerobic bacteria from surgical site infection and their antibiotic susceptibility pattern in a tertiary care hospital in Nepal. Materials and Methods: A descriptive cross-sectional study was conducted at a tertiary care center with effect from September 2022 to September 2023 approval from the Institutional Review Committee. Pus samples were taken from the postoperative wound infection site and submitted to the microbiological laboratory for culture and sensitivity. Gram-positive aerobic bacteria and gram-negative aerobic bacteria were isolated and identified by standard microbiological procedures. An antimicrobial susceptibility test was done on Muller-Hinton agar using the Kirby Bauer disc diffusion method. The result was interpreted according to clinical and laboratory standard institute guidelines. Results: The rate of surgical site infection was 22.24% and the most common organisms isolated were Staphylococcus aureus followed by Escherichia coli and Pseudomonas aeruginosa. All the gram-positive cocci were sensitive to linezolid, teicoplanin, and vancomycin and gram-negative bacteria were sensitive to meropenem, piperacillin/tazobactam, cefoperazone/sulbactam and cefepime. Conclusion: The present study concluded that the most common aerobic bacteria isolated from surgical site infection in our setting was found to be Staphylococcus aureus. This study also showed that the gram-positive aerobic bacteria were most susceptible tolinezolid, and teicoplanin, and gram-negative aerobic bacteria were sensitive to meropenem, piperacillin/tazobactam, and cefoperazone/sulbactam.

Aerobic Bacteria and Their Antibiotic Resistance Profile in Neonatal Septicaemia: A cross Sectional Study in a Tertiary Care Hospital of Rajshahi, Bangladesh

Objective: Neonatal sepsis is an infection of the bloodstream in infants younger than 28 days old. It continues to be the major cause of morbidity and mortality among newborns, particularly in middle- and low-income nations. The objective of this study was to isolate and identify aerobic bacteria of neonatal sepsis by blood culture using FAN method followed by subculture and relevant biochemical tests. Methods: It was a cross sectional type of descriptive study where the sample size was 95 and data were collected purposively from the clinically suspected neonatal septicaemia cases from inpatient Pediatric department in Rajshahi Medical College Hospital, Rajshahi. Results: Most 34 (35.79%) of the cases were culture positive, whereas 61 (64%) were culture negative. 7 (21%) of the 34 positive cases were Gram-positive, while 27 (79%) were Gram-negative. S. aureus was found in 6 (17.65%) of the culture-positive isolates, followed by CoNS with 1 (02.94%), E. coli with 14 (41.17%), Klebsiella spp. with 6 (17.65%), P. aeruginosa with 6 (17.65%), and Acinetobacter with 1 (02.94%). Gram-positive bacteria were extremely susceptible to Vancomycin (90%), Gentamicin (90%), and Ciprofloxacin (80%) based on antibacterial susceptibility testing. Colistin (100%) and ampicillin (100%) exhibited the greatest resistance. Meropenem (90%), Amikacin (90%), and Colistin (89%) were the most effective antibiotics against Gram-negative bacteria, whereas Ceftazidime (60%) was the least effective. Vancomycin (100%) and ampicillin (100%) exhibited the highest degree of resistance. Conclusion: Both Gram-positive and Gram-negative aerobic bacteria were related with newborn septicaemia, and a significant proportion of them were resistant to multiple medicines. CME J 2024; 3(2); 4-11

Microbiological profile of diabetic foot infections in China and worldwide: a 20-year systematic review.

Pathogens causing diabetic foot infections (DFIs) vary by region globally; however, knowledge of the causative organism is essential for effective empirical treatment. We aimed to determine the incidence and antibiotic susceptibility of DFI pathogens worldwide, focusing on Asia and China. Through a comprehensive literature search, we identified published studies on organisms isolated from DFI wounds from January 2000 to December 2020. Based on our inclusion criteria, we analyzed 245 studies that cumulatively reported 38,744 patients and 41,427 isolated microorganisms. DFI pathogens varied according to time and region. Over time, the incidence of Gram-positive and Gram-negative aerobic bacteria have decreased and increased, respectively. America and Asia have the highest (62.74%) and lowest (44.82%) incidence of Gram-negative bacteria, respectively. Africa has the highest incidence (26.90%) of methicillin-resistant Staphylococcus aureus. Asia has the highest incidence (49.36%) of Gram-negative aerobic bacteria with species infection rates as follows: Escherichia coli, 10.77%; Enterobacter spp., 3.95%; and Pseudomonas aeruginosa, 11.08%, with higher local rates in China and Southeast Asia. Linezolid, vancomycin, and teicoplanin were the most active agents against Gram-positive aerobes, while imipenem and cefoperazone-sulbactam were the most active agents against Gram-negative aerobes. This systematic review showed that over 20 years, the pathogens causing DFIs varied considerably over time and region. This data may inform local clinical guidelines on empirical antibiotic therapy for DFI in China and globally. Regular large-scale epidemiological studies are necessary to identify trends in DFI pathogenic bacteria. https://www.crd.york.ac.uk/prospero/, identifier CRD42023447645.

Omadacycline for the treatment of patients with Legionella pneumophila pneumonia after experiencing liver dysfunction: case series.

Antibiotics frequently induce abnormal liver function. Omadacycline is a novel aminomethylcycline antibiotic, which shows potent activity against Gram-positive and Gram-negative aerobic, anaerobic, and atypical (including Legionella pneumophila) bacteria. Of note, omadacycline is tolerable in most patients with liver impairment. However, evidence regarding the application of omadacycline in patients with Legionella pneumophila pneumonia after experiencing liver dysfunction is scarce. The current study reported 6 cases of patients with Legionella pneumophila pneumonia receiving omadacycline as subsequent antibiotics after experiencing liver dysfunction. These 6 cases were admitted to the hospital for pneumonia and received antibiotic therapy, including piperacillin-tazobactam, imipenem, meropenem, and moxifloxacin. After receiving these antibiotics, increased liver enzymes were noted. Although hepatoprotective therapy (such as magnesium isoglycyrrhizinate and glutathione) was given, the liver function was still abnormal. According to metagenomic next-generation sequencing, these patients were diagnosed with Legionella pneumophila pneumonia. Considering the abnormal liver function, the antibiotic therapy was switched to omadacycline-containing antibiotic therapy. After that, liver function was improved, and the infection was ameliorated. Ultimately, all patients discharged from the hospital, including 2 patients who achieved complete clinical symptomatic improvement and 4 patients who achieved partial clinical symptomatic improvement. This study emphasizes the successful treatment of switching to omadacycline after experiencing abnormal liver function in patients with Legionella pneumophila pneumonia. This study suggests that omadacycline may serve as an optional antibiotic for patients with Legionella pneumophila pneumonia, especially when occurring liver dysfunction. However, more clinical studies are required to validate our findings.

The detailed analysis of the microbiome and resistome of artisanal blue-veined cheeses provides evidence on sources and patterns of succession linked with quality and safety traits

BackgroundArtisanal cheeses usually contain a highly diverse microbial community which can significantly impact their quality and safety. Here, we describe a detailed longitudinal study assessing the impact of ripening in three natural caves on the microbiome and resistome succession across three different producers of Cabrales blue-veined cheese.ResultsBoth the producer and cave in which cheeses were ripened significantly influenced the cheese microbiome. Lactococcus and the former Lactobacillus genus, among other taxa, showed high abundance in cheeses at initial stages of ripening, either coming from the raw material, starter culture used, and/or the environment of processing plants. Along cheese ripening in caves, these taxa were displaced by other bacteria, such as Tetragenococcus, Corynebacterium, Brevibacterium, Yaniella, and Staphylococcus, predominantly originating from cave environments (mainly food contact surfaces), as demonstrated by source-tracking analysis, strain analysis at read level, and the characterization of 613 metagenome-assembled genomes. The high abundance of Tetragenococcus koreensis and Tetragenococcus halophilus detected in cheese has not been found previously in cheese metagenomes. Furthermore, Tetragenococcus showed a high level of horizontal gene transfer with other members of the cheese microbiome, mainly with Lactococcus and Staphylococcus, involving genes related to carbohydrate metabolism functions. The resistome analysis revealed that raw milk and the associated processing environments are a rich reservoir of antimicrobial resistance determinants, mainly associated with resistance to aminoglycosides, tetracyclines, and β-lactam antibiotics and harbored by aerobic gram-negative bacteria of high relevance from a safety point of view, such as Escherichia coli, Salmonella enterica, Acinetobacter, and Klebsiella pneumoniae, and that the displacement of most raw milk-associated taxa by cave-associated taxa during ripening gave rise to a significant decrease in the load of ARGs and, therefore, to a safer end product.ConclusionOverall, the cave environments represented an important source of non-starter microorganisms which may play a relevant role in the quality and safety of the end products. Among them, we have identified novel taxa and taxa not previously regarded as being dominant components of the cheese microbiome (Tetragenococcus spp.), providing very valuable information for the authentication of this protected designation of origin artisanal cheese.A8MAe52mDCf21YyaVzbpABVideo

Tackling carbapenem resistance: ceftazidime - avibactam in contemporary clinical scenarios

Antimicrobial resistance poses a formidable challenge in treating severe infections, with the prevalence of extended-spectrum beta-lactamase (ESBL) - producing, Klebsiella pneumoniae carbapenemase (KPC) - producing, and multidrug-resistant (MDR) organisms on the rise. This necessitates careful consideration of various factors, including local resistance patterns, patient-specific characteristics, and drug properties, in treatment decisions for critically ill patients. Ceftazidime-Avibactam demonstrates efficacy against aerobic Gram-negative bacteria and offers a crucial advancement against carbapenem-resistant organisms (CRO) with its effectiveness against key pathogens, including ESBL, AmpC, KPC, and OXA-48-producing Enterobacteriaceae and drug-resistant P. aeruginosa. Ceftazidime-Avibactam emerges as a valuable option for critically ill patients with limited treatment choices. The drug's excellent safety profile demonstrated in clinical trials, further positions it as a crucial addition to antimicrobial treatment options. As the global threat of drug-resistant bacteria grows, Ceftazidime-Avibactam plays a pivotal role in addressing this challenge and offers a promising solution for critically ill patients facing infections caused by antimicrobial-resistant pathogens. The article delves into therapeutic efficacy and the prospective role of Ceftazidime-Avibactam in managing MDR Gram-negative organisms, underscoring the critical role of appropriate antibiotic administration in reducing mortality associated with Gram-negative infections.

Deciphering the Mechanism by Which Carbon Dioxide Extends the Shelf Life of Raw Milk: A Microbiomics- and Metabolomics-Based Approach.

Microbial community succession in raw milk determines its quality and storage period. In this study, carbon dioxide (CO2) at 2000 ppm was used to treat raw milk to investigate the mechanism of extending the shelf life of raw milk by CO2 treatment from the viewpoint of microbial colonies and metabolites. The results showed that the shelf life of CO2-treated raw milk was extended to 16 days at 4 °C, while that of the control raw milk was only 6 days. Microbiomics analysis identified 221 amplicon sequence variants (ASVs) in raw milk, and the alpha diversity of microbial communities increased (p < 0.05) with the extension of storage time. Among them, Pseudomonas, Actinobacteria and Serratia were the major microbial genera responsible for the deterioration of raw milk, with a percentage of 85.7%. A combined metagenomics and metabolomics analysis revealed that microorganisms altered the levels of metabolites, such as pyruvic acid, glutamic acid, 5'-cmp, arginine, 2-propenoic acid and phenylalanine, in the raw milk through metabolic activities, such as ABC transporters, pyrimidine metabolism, arginine and proline metabolism and phenylalanine metabolism, and reduced the shelf life of raw milk. CO2 treatment prolonged the shelf life of raw milk by inhibiting the growth of Gram-negative aerobic bacteria, such as Acinetobacter guillouiae, Pseudomonas fluorescens, Serratia liquefaciens and Pseudomonas simiae.

Investigating antimicrobial-resistant bacteria from exotic domestic birds - a One Health concern.

Antimicrobial resistance is a natural mechanism in microorganisms, making the treatment of infections more complex in human and veterinary medicine. Global exotic and ornamental bird markets have significantly increased, and the close relationship between pets and humans makes exploring the potential role of these birds as vectors for the spread of antimicrobial-resistant bacteria imperative. This study aimed to use culture-dependent methods to investigate cloacal bacteria and the presence of antibiotic-resistant bacteria in four breeding stocks of ornamental birds. Cloacal swab samples were collected from 53 birds (canaries = 32, cockatiels = 17, and budgies = 4) and used for culturing and isolating facultative anaerobic and/or obligatory aerobic Gram-positive and Gram-negative bacteria. The antimicrobial susceptibility profile of each isolate was determined by the disk diffusion method. Thirty-four isolates were obtained, most of which belonged to the Staphylococcus genus. Bacterial richness was higher in canaries and in one of the breeding stockings, where Gram-negative bacteria were more abundant than in the others. In addition, canaries exhibited a predominance of resistant isolates, particularly multidrug-resistant strains, probably due to prophylactic antimicrobial usage. Most Gram-negative bacteria were resistant to at least one drug tested. A vancomycin-resistant Enterococcus faecalis strain was isolated. Most Staphylococcus strains were resistant to gentamycin, followed by penicillin. Eight strains were cefoxitin-resistant, including oxacillin-resistant S. epidermidis, in which the mecA gene was detected. Understanding the prevalence of resistance in avian species is crucial in the collaborative pursuit of maintaining antibiotic effectiveness and strengthening public health defense against emerging infectious risks.

Evaluating the Potential Safety Risk of Plant-Based Meat Analogues by Analyzing Microbial Community Composition.

Plant-based meat analogues offer an environmentally and scientifically sustainable option as a substitute for animal-derived meat. They contribute to reducing greenhouse gas emissions, freshwater consumption, and the potential risks associated with zoonotic diseases linked to livestock production. However, specific processing methods such as extrusion or cooking, using various raw materials, can influence the survival and growth of spoilage and pathogenic microorganisms, resulting in differences between plant-based meat analogues and animal meat. In this study, the microbial communities in five different types of plant-based meat analogues were investigated using high-throughput sequencing. The findings revealed a diverse range of bacteria, including Cyanobacteria, Firmicutes, Proteobacteria, Bacteroidota, Actinobacteriota, and Chloroflexi, as well as fungi such as Ascomycota, Basidiomycota, Phragmoplastophyta, Vertebrata, and Mucoromycota. Additionally, this study analyzed microbial diversity at the genus level and employed phenotype prediction to evaluate the relative abundance of various bacterium types, including Gram-positive and Gram-negative bacteria, aerobic, anaerobic, and facultative anaerobic bacteria, as well as potential pathogenic bacteria. The insights gained from this study provide valuable information regarding the microbial communities and phenotypes of different plant-based meat analogues, which could help identify effective storage strategies to extend the shelf-life of these products.

Microbial communities of a variety of 75 homemade fermented vegetables.

Fermentation is an ancient practice of food preservation. Fermented vegetables are popular in Eastern European and Asian countries. They have received a growing interest in Western countries, where they are mainly manufactured at domestic and artisanal scales and poorly characterized. Our aim was to investigate the microbial communities and the safety of French homemade fermented vegetables, in the frame of a citizen science project. Fermented vegetables and the data associated with their manufacture were collected from citizens and characterized for pH, NaCl concentration, and microbiology by culturomics and 16S DNA metabarcoding analysis. Lactic acid bacteria (LAB) and yeast isolates were identified by 16S rRNA gene sequencing and D1/D2 domains of the large subunit of the rRNA gene, respectively. The 75 collected samples contained 23 types of vegetables, mainly cabbage, followed by carrots and beets, and many mixtures of vegetables. They were 2 weeks to 4 years old, and their median pH was 3.56, except for two samples with a pH over 4.5. LAB represented the dominant viable bacteria. LAB concentrations ranged from non-detectable values to 8.7 log colony-forming units (CFU)/g and only depended on the age of the samples, with the highest most frequently observed in the youngest samples (<100 days). The 93 LAB isolates identified belonged to 23 species, the two mains being Lactiplantibacillus pentosus/plantarum and Levilactobacillus brevis. The other microbial groups enumerated (total aerobic bacteria, halotolerant bacteria, Gram-negative bacteria, and acetic acid bacteria) generally showed lower concentrations compared to LAB concentrations. No pathogenic bacteria were detected. Viable yeasts were observed in nearly half the samples, at concentrations reaching up to 8.0 log CFU/g. The 33 yeast clones identified belonged to 16 species. Bacterial metabarcoding showed two main orders, namely, Lactobacillales (i.e., LAB, 79% of abundance, 177 of the 398 total ASVs) and Enterobacterales (19% of abundance, 191 ASVs). Fifteen LAB genera were identified, with Lactiplantibacillus and Levilactobacillus as the most abundant, with 41 and 12% of total reads, respectively. Enterobacterales members were mainly represented by Enterobacteriaceae and Yersiniaceae. This study is the first wide description of the microbiota of a large variety of homemade fermented vegetables and documents their safety.

Distribution, characterization, and evolution of heavy metal resistance genes and Tn7-like associated heavy metal resistance Gene Island of Burkholderia

IntroductionBurkholderia is a rod-shaped aerobic Gram-negative bacteria with considerable genetic and metabolic diversity, which can beused for bioremediation and production applications, and has great biotechnology potential. However, there are few studies on the heavy metal resistance of the Burkholderia genus.MethodsIn this paper, the distribution, characteristics and evolution of heavy metal resistance genes in Burkholderia and the gene island of Tn7-like transposable element associated with heavy metal resistance genes in Burkholderia were studied by comparative genomic method based on the characteristics of heavy metal resistance.Results and discussionThe classification status of some species of the Burkholderia genus was improved, and it was found that Burkholderia dabaoshanensis and Burkholderia novacaledonica do not belong to the Burkholderia genus.Secondly, comparative genomics studies and pan-genome analysis found that the core genome of Burkholderia has alarger proportion of heavy metal resistance genes and a greater variety of heavy metalresistance genes than the subsidiary genome and strain specific genes. Heavy metal resistance genes are mostly distributed in the genome in the form of various gene clusters (for example, mer clusters, ars clusters, czc/cusABC clusters). At the same time, transposase, recombinase, integrase and other genes were foundupstream and downstream of heavy metal gene clusters, indicating that heavy metal resistance genes may beobtained through horizontal transfer. The analysis of natural selection pressure of heavy metal resistance genes showed that heavy metal resistance genes experienced strong purification selection under purification selection pressure in the genome.The Tn7 like transposable element of Burkholderia was associated with the heavy metal resistance gene island, and there were a large number of Tn7 transposable element insertion events in genomes. At the same time, BGI metal gene islands related to heavy metal resistance genes of Tn7 like transposable element were found, and these gene islands were only distributed in Burkholderia cepacia, Burkholderia polyvora, and Burkholderia contaminant.

A Cross-Over Randomized Controlled Clinical Trial for Evaluation of Two Hygiene Protocols on Microbial Load, Tissue Health, and Opinion of Ocular Prosthesis Wearers

The recommendations for the wear and hygiene of ocular prostheses can vary among practitioners, and it is still a controversial theme in the literature. This clinical trial evaluated the microbial load, tissue health of the socket, and the participants’ opinions before and after the use of two hygiene protocols. Thirty ocular prosthesis wearers used either a Daily Protocol (DPt: hygiene once a day) or Weekly Protocol (WPt: hygiene once a week) for 5 weeks with a washout of 7 days. The microbial load was quantified by the colony-forming unit count of the aerobic bacteria, Candida spp., Staphylococcus spp., and Gram-negative bacteria. The tissue health of the socket was evaluated by scores, and patients’ opinion of the protocols was evaluated using the analogic visual scale (VAS). Data were analyzed by ANOVA Repeated Measures, Friedman, Cochran’s Q Test, Wilcoxon, Fisher, and Pearson’s chi-square tests considering p &lt; 0.05. There was no difference in the microbial load of the microorganisms (p &gt; 0.05). Both protocols improved socket inflammation (p = 0.005) and discharge (p &lt; 0.001); DPt improved edema (p = 0.021) and crusting (p = 0.020). There was no difference in patients’ rating responses (VAS) for all the questions of patients’ opinion (Q1: p = 1.0; Q2: p = 1.0; Q3: p = 1.0; Q4: p = 1.0; Q5: p = 1.0; Q6: p = 0.317; Q7: p = 1.0; Q8: p = 0.159). There was a correlation between eye drops/edema (p = 0.030), eye drops/pain (p = 0.016), microbial load with discharge, inflammation, eyelid edema, and pain. Inflammation was correlated with edema at baseline (p &lt; 0.001) and after DPt (p = 0.018), and with crusting at baseline (p = 0.003); edema was correlated with crusting at baseline (p &lt; 0.001); crusting was correlated with discharge after WPt (p &lt; 0.001). The protocols showed no effects on the microbial load of the anophthalmic socket and ocular prosthesis. However, better tissue health and patient acceptance were observed after both regimens.

Moxifloxacin loaded microspheres-composed gel for controlled release and enhanced penetration in ocular tissues: In vitro, ex vivo and in vivo proof of concept

Microspheres-enriched ocular gels are proposed in this work for the loading of a model quinolone antibiotic of broad-spectrum - moxifloxacin hydrochloride (MXF) - as an approach to achieve a controlled release profile and enhance drug's bioavailability in ocular milieu. MXF is a synthetic fluoroquinolone antibacterial agent used for treatment of ocular diseases caused by strains of aerobic gram positive and gram-negative bacteria, besides others. MXF-loaded Eudragit RS microspheres were prepared by emulsion solvent evaporation method, as previously described by us. Optimized microspheres were characterized and then formulated in an ocular gel. Hydrophilic polymeric base HPMC K100 was used as gelling agent. Ocular gel enriched with microspheres was evaluated for its physicochemical parameters, in vitro drug release, ex vivo corneal and scleral permeation and bioadhesion, in vivo primary eye irritation and in vivo efficacy study. The developed MXF microspheres dispersed in an ocular gel showed an in vitro drug release over a period 12 h, improved corneal and scleral penetration and increased therapeutic efficacy with a reduced administration frequency which may contribute to increase patient's compliance to ocular treatment.

Self emulsifying drug delivery system: norfloxacin model drug

Background Norfloxacin is a synthetic antibacterial fluoroquinolone that is poorly water soluble and active against a wide spectrum of gram-positive and gram-negative aerobic bacteria. The goal of this work was to create a self-nanoemulsion (SNE) as a colloidal dispersed drug delivery system for increasing norfloxacin dissolving rate, while also assuming intestinal lymphatic transport participation for such a nano-size system that would increase norfloxacin oral bioavailability. Methods Depending on the solubility of norfloxacin in various components, several formulations of liquid SNEDDS of the antibiotic were created using oleic acid (oil), tween20 (surfactant), and PEG200 (co-surfactant). To assess the presence of a nanoemulsion region, phase diagram was generated at various oil: surfactant: co-surfactant ratios. Results The in-vitro dissolution profile suggested an optimum norfloxacin SEDD formulation (F1) comprised of oleic acid (10%), tween 20 (45%), and PEG200 (45%), as opposed to commercially available traditional tablets. The F1 formula exhibited thermodynamic stability with a zeta potential of +60.78mV and a droplet size of 57.4nm. The F1 formula revealed an improved dissolving profile as compared to the commercial Tablet of norfloxacin. Conclusion Based on the findings, this study indicated that preparing norfloxacin as a liquid self-nanoemulsifying system improved the solubility and drug release of norfloxacin counteract the inconsistent bioavailability of the commercial tablet.

DETECTION OF EXTENDED SPECTRUM BETA LACTAMASES-PRODUCING KLEBSIELLA PNEUMONIAE ISOLATES IN CHRONIC OBSTRUCTIVE PULMONARY DISEASES PATIENTS

Objective: Chronic obstructive pulmonary disease (COPD) is the leading cause of morbidity and mortality worldwide which includes chronic bronchitis and emphysema. 80% of acute exacerbation of COPD (AECOPD) are triggered by respiratory viruses, atypical bacteria, and aerobic Gram-positive and Gram-negative bacteria. The aim of our study was to analyze the prevalence and antimicrobial susceptibility testing of Klebsiella pneumoniae and detection of extended spectrum beta lactamases (ESBL)-producing K. pneumoniae isolates from COPD patients. Methods: Sputum samples received from seventy-five diagnosed cases of COPD from the department of General Medicine and Chest Medicine, TSRM MCH and RC, Trichy, from March 2022 to August 2022. Direct Gram stain was done for all sputum samples. The suitable sputum samples were cultured. The identification of organism and antimicrobial susceptibility testing was done by standard microbiological techniques. Results: Out of seventy-five cases, 64% were males and 36% were females. Forty-seven were sputum positive, and the prevalence of Gram- negative bacteria was 64%. K. pneumoniae was the most common bacteria isolated (42.2%), followed by Pseudomonas aeruginosa (15.5%). Antimicrobial susceptibility testing of K. pneumoniae was sensitive to imipenem (78.94%), aminoglycosides (78.94%), amoxycillin-clavulinic acid (63.15%), ciprofloxacin (57.89%), Piperacillin-Taxobactam (57.89%), and the phenotypic tests showed 13 (68%) isolates were ESBL producers. Conclusion: This study showed that K. pneumoniae and P. aeruginosa are the most common organisms associated with AECOPD and increased rate of ESBL producers were observed.

Molecular basis of the pleiotropic effects by the antibiotic amikacin on the ribosome

Aminoglycosides are a class of antibiotics that bind to ribosomal RNA and exert pleiotropic effects on ribosome function. Amikacin, the semisynthetic derivative of kanamycin, is commonly used for treating severe infections with multidrug-resistant, aerobic Gram-negative bacteria. Amikacin carries the 4-amino-2-hydroxy butyrate (AHB) moiety at the N1 amino group of the central 2-deoxystreptamine (2-DOS) ring, which may confer amikacin a unique ribosome inhibition profile. Here we use in vitro fast kinetics combined with X-ray crystallography and cryo-EM to dissect the mechanisms of ribosome inhibition by amikacin and the parent compound, kanamycin. Amikacin interferes with tRNA translocation, release factor-mediated peptidyl-tRNA hydrolysis, and ribosome recycling, traits attributed to the additional interactions amikacin makes with the decoding center. The binding site in the large ribosomal subunit proximal to the 3’-end of tRNA in the peptidyl (P) site lays the groundwork for rational design of amikacin derivatives with improved antibacterial properties.

Drug Utilization Evaluation and Impact of Pharmacist Interventions on Optimization of Piperacillin/Tazobactam Use: A Retrospective Analysis and Prospective Audit.

(1) Background: Piperacillin/tazobactam is a broad-spectrum antimicrobial encompassing most Gram-positive and Gram-negative aerobic and anaerobic bacteria. The inappropriate use of such broad-spectrum antibiotics is an important contributor to the rising rates of antimicrobial drug resistance worldwide. Drug utilization evaluation studies and pharmacists' interventions are vital to assess, develop, and promote the rational use of antibiotics. This drug utilization study aimed to evaluate the current utilization practice of piperacillin/tazobactam in a hospital setting and assess the impact of pharmacist intervention in improving its appropriate use. (2) Methodology: In this study, we used a retrospective cohort and a prospective cohort, a cross-sectional, observational method. It included a retrospective (Cycle A/pre-intervention-CycA) phase followed by an educational interventional phase conducted by the pharmacists. During the 2 months of educational intervention, pharmacists used several methods, including workshops, lectures, oral presentations, and the development and reinforcement of clinical pathways to promote the judicious use of piperacillin/tazobactam. This was followed by a prospective (Cycle B/post-intervention-CycB) phase to improve piperacillin/tazobactam usage appropriateness. The appropriateness criteria for this drug utilization evaluation were established based on antimicrobial guidelines, the published literature, the institutional antibiogram, consultation from the antimicrobial stewardship committee, and the product monograph (Tazocin). The appropriateness of CycA and CycB patients was compared using the measurable elements, including indication and dose based on renal function, timely order for cultures, de-escalation, and use of extended infusion protocol. (3) Results: The study population comprised 100 patients in both CycA and CycB. The mean age of the patients was 66.28 ± 16.15 and 67.35 ± 17.98, and the ratios of men to women were found to be 49:51 and 61:39 in CycA and CycB, respectively. It was observed that inappropriate usage was high in CycA patients, and the appropriateness was improved in CycB patients. A total of 31% of inappropriate empirical broad-spectrum use was found in CycA, and it was reduced to 12% in CycB patients. The transition of appropriateness was observed in all measurable criteria, which includes the optimized dose according to the renal function (CycA = 49% to CycB = 94%), timely bacterial culture orders (CycA = 47% to CycB = 74%), prompt de-escalation (CycA = 31% to CycB = 53%), and adherence to extended infusion institutional guidelines (CycA = 34% to CycB = 86%). (4) Conclusions: The study highlighted important aspects of inappropriate piperacillin/tazobactam use. This can be considerably improved by proper education and timely interventions based on the pharmacists' vigilant approach. The study results emphasized the need for surveillance of piperacillin/tazobactam usage by conducting similar drug utilization evaluations and practice to improve quality and safety in healthcare organizations globally.

Whole-Genome Sequencing of the Novel Pseudomonas Strain TUM22785 Harboring blaPAM-1, Isolated from a Patient with Urinary Tract Infection in Japan.

Pseudomonas species are Gram-negative aerobic bacteria that cause opportunistic infections. Here, we report the whole-genome sequence of the Pseudomonas sp. strain TUM22785, isolated from an outpatient with a urinary tract infection at a medical institution in Japan. This strain harbors a metallo-β-lactamase (MBL) blaPAM-1 gene.

Microbial Prevalence and Outcome of Diabetic Foot Ulcers in Patient’s Candidates for Minor Surgical Interventions

Background: Diabetes mellitus is a progressive disease with chronic complications such as diabetic foot infection, a significant difficulty that inevitably leads to gangrene and amputations.&#x0D; &#x0D; Objective: This study aims to determine microbial prevalence in diabetic foot infections, identify the significance of aggressive surgical therapy and minor amputations in limb salvage and the prevention of more proximal amputations, and identify predicting factors affecting the outcome of these surgical processes.&#x0D; &#x0D; Methods: In this cohort study, microbiological samples were collected from 62 patients with diabetic foot lesions who underwent debridement or minor amputations to determine the prevalence of microorganisms in diabetic foot infections. Then, they were followed up to determine the rate of saved limbs and the factors that affect the outcomes and rate of complications.&#x0D; &#x0D; Results: infections were mainly caused by aerobic Gram-positive bacteria (S. aureus) 53.5%, and aerobic Gram-negative bacteria of enterobacter species 40.4%. Regarding the outcome of surgical intervention, we found an 80.65% success rate of saving the limb with a 30.6% complication rate. Risk factors such as high levels of inflammatory markers and parameters of the severity of peripheral arterial disease showed significant association with the rate of complications and poor outcomes.&#x0D; &#x0D; Conclusions: Debridement and minor surgical amputations effectively prevent more proximal amputations in diabetic foot infections with a high chance of good results. At the same time, the common microorganism in our local population was S. aureus, followed by P. mirabilis, E. coli, and Klebsiella species in diabetic foot infections.