Phylogenetic study of metallo-β-lactamase producing multidrug resistant Pseudomonas aeruginosa isolates from burn patients

A systematic review and meta-analysis to develop a landscape map of antibiotic resistance for six WHO priority pathogens in east and north-east India from 2011 to 2022

BACKGROUND

Determining regional patterns of antimicrobial resistance in bacterial infections in the healthcare setting (AMR) identifies surveillance gaps and informs policies for mitigation. We estimated the prevalence of AMR for six WHO priority pathogens in diagnostic and surveillance samples in the twelve east and north-east Indian states from 2011 to 2022 (PROSPERO ID: CRD42021278961).

METHODS

Studies were searched on Medline, Scopus, and Web of Science. Observational, descriptive, and cross-sectional studies, reporting AMR based on laboratory diagnostics, in individuals from east and north-east India from 2011 to 2022 were included. Four reviewers in pairs conducted abstract, full-text screening, and data extraction. We estimated the prevalence of resistance in fifty-four pathogen-antibiotic combinations, and six antibiotic resistance patterns. Pooled estimates of prevalence (Ɵ), heterogeneity (I2), and 95 % confidence intervals were calculated using the random effects model.

RESULTS

Fifty-five studies were included. Information was available for nine states, none from Arunachal Pradesh, Mizoram, and Nagaland. E. coli was most frequently isolated (59.2 %, 95 % CI: 48.8-69.6 %), followed by S. aureus (36.2 %, 95 % CI: 20.2-52.2 %), Enterococcus (27.5 %, 95 % CI: 11.2-43.7 %), Klebsiella (25 %, 95 % CI: 15-35 %), Acinetobacter (15.7 %, 95 % CI: 2.3-29.1 %), and Pseudomonas aeruginosa (15.7 %, 95 % CI: 4.1-27.3 %). There was high prevalence of ESBL (45 %, 95 % CI: 35-55 %) and carbapenem resistance (30 %, 95 % CI: 22-38 %). AmpC (23 %, 95 % CI: 9-37 %) and colistin resistance was lower (10 %, 95 % CI: 0-22 %) but supporting data was limited. Overall prevalence of MRSA was 26 % (95 % CI: 14-39 %), and VRE was 9 % (95 % CI: 0-17 %).

CONCLUSION

High prevalence of resistance was seen to all first-line antibiotics. Gram positive bacteria had high resistance to penicillins, and Gram negatives to third-generation cephalosporins, beta-lactam/beta-lactamase inhibitors, and carbapenems. Aminoglycoside, fluoroquinolone, and trimethoprim-sulphamethoxazole resistance was common across all genera. Critical regional AMR information gaps exist.

Biological characteristics of stem cells derived from burned skin-a comparative study with umbilical cord stem cells

INTRODUCTION

Burned human skin, which is routinely excised and discarded, contains viable mesenchymal stromal/stem cells (burn-derived mesenchymal stromal/stem cells; BD-MSCs). These cells show promising potential to enable and aid wound regeneration. However, little is known about their cell characteristics and biological function.

OBJECTIVES

This study had two aims: first, to assess critical and cellular characteristics of BD-MSCs and, second, to compare those results with multipotent well-characterized MSCs from Wharton's jelly of human umbilical cords (umbilical cord mesenchymal stromal/stem cells, UC-MSCs).

METHODS

BD- and UC-MSCs were compared using immunophenotyping, multi-lineage differentiation, seahorse analysis for glycolytic and mitochondrial function, immune surface markers, and cell secretion profile assays.

RESULTS

When compared to UC-MSCs, BD-MSCs demonstrated a lower mesenchymal differentiation capacity and altered inflammatory cytokine secretomes at baseline and after stimulation with lipopolysaccharides. No significant differences were found in population doubling time, colony formation, cell proliferation cell cycle, production of reactive oxygen species, glycolytic and mitochondrial function, and in the expression of major histocompatibility complex I and II and toll-like receptor (TLR).

IMPORTANCE, TRANSLATION

This study reveals valuable insights about MSCs obtained from burned skin and show comparable cellular characteristics with UC-MSCs, highlighting their potentials in cell therapy and skin regeneration.

Extensive colonization with carbapenemase-producing microorganisms in Romanian burn patients: infectious consequences from the Colectiv fire disaster

Health care of severe burn patients is highly specialized and may require international patient transfer. Burn patients have an increased risk of developing infections. Patients that have been hospitalized in countries where carbapenemase-producing microorganisms (CPMO) are endemic may develop infections that are difficult to treat. In addition, there is a risk on outbreaks with CPMOs in burn centers. This study underlines that burn patients may extensively be colonized with CPMOs, and it provides best practice recommendations regarding clinical microbiology and infection control. We evaluated CPMO-carriage and wound colonization in a burn patient initially treated in Romania, and transported to the Netherlands. The sequence types and acquired beta-lactamase genes of highly-resistant microorganisms were derived from next generation sequencing data. Next, we searched literature for reports on CPMOs in burn patients. Five different carbapenemase-producing isolates were cultured: two unrelated OXA-48-producing Klebsiella pneumoniae isolates, OXA-23-producing Acinetobacter baumanii, OXA-48-producing Enterobacter cloacae, and NDM-1-producing Providencia stuartii. Also, multi-drug resistant Pseudomonas aeruginosa isolates were detected. Among the sampling sites, there was high variety in CPMOs. We found 46 reports on CPMOs in burn patients. We listed the epidemiology of CPMOs by country of initial treatment, and summarized recommendations for care of these patients based on these reports and our study.

Genetic diversity study of various β-lactamase-producing multidrug-resistant Escherichia coli isolates from a tertiary care hospital using ERIC-PCR

BACKGROUND & OBJECTIVES

The prevalence of multidrug-resistant (MDR) Escherichia coli isolates producing β-lactamase enzyme is a growing problem across the globe. Strain typing is an epidemiologically important tool not only for detecting the cross transmission of nosocomial pathogens but also for determining the source of infection. The present study was conducted to understand the clonal relationship among various β-lactamase-producing MDR E. coli isolates using enterobacterial repetitive intergenic consensus (ERIC) polymerase chain reaction (PCR).

METHODS

A total of 41 MDR E. coli isolates were randomly collected from various clinical samples and processed. Isolated organisms were tested for antibiotics resistance pattern. Phenotypic detection of metallo β-lactamases (MBL) was carried out by the imipenem-ethylenediaminetetraacetic acid disc diffusion/double-disc synergy test. AmpC enzyme production was tested by a modified three-dimensional extract test.

RESULTS

Almost all isolates were found sensitive to colistin. A high percentage of drug resistance was observed in these isolates against ceftazidime (100%), cefotaxime (100%), cefepime (100%), ofloxacin (97.56%), amoxicillin/clavulanic acid (97.56%) and norfloxacin (85.36%). Of the 41 isolates, ESBL producers were found to be predominant, i.e., 22 (53.65%), followed by AmpC (6, 14.63%) and MBL (5, 12.19%).

INTERPRETATION & CONCLUSIONS

At 60 per cent similarity cut-off value, the dendrogram analysis showed that there were a total of 14 unique clusters of ERIC (CL-1 - CL-14) within the 41 E. coli isolates, which revealed the genetic diversity existing between them.

Solvent-Free Microwave-Assisted Extraction of Polyphenols from Olive Tree Leaves: Antioxidant and Antimicrobial Properties

Response surface methodology (RSM) and artificial neural networks (ANN) were evaluated and compared in order to decide which method was the most appropriate to predict and optimize total phenolic content (TPC) and oleuropein yields in olive tree leaf (Oleaeuropaea) extracts, obtained after solvent-free microwave-assisted extraction (SFMAE). The SFMAE processing conditions were: microwave irradiation power 250-350 W, extraction time 2-3 min, and the amount of sample 5-10 g. Furthermore, the antioxidant and antimicrobial activities of the olive leaf extracts, obtained under optimal extraction conditions, were assessed by several in vitro assays. ANN had better prediction performance for TPC and oleuropein yields compared to RSM. The optimum extraction conditions to recover both TPC and oleuropein were: irradiation power 250 W, extraction time 2 min, and amount of sample 5 g, independent of the method used for prediction. Under these conditions, the maximal yield of oleuropein (0.060 ± 0.012 ppm) was obtained and the amount of TPC was 2.480 ± 0.060 ppm. Moreover, olive leaf extracts obtained under optimum SFMAE conditions showed antibacterial activity against S.aureus and S.epidermidis, with a minimum inhibitory concentration (MIC) value of 1.25 mg/mL.

Rapid detection of blaNDM-1 in multidrug-resistant organisms using a novel electrochemical biosensor

The traditional detection methods of multidrug-resistant organisms (MDROs) are costly and comprise multiple steps. In this study, we successfully established a fast electrochemical method for blaNDM-1 in MDROs based on the LNA probes.

The frequency of genes encoding exotoxin A and exoenzyme S in Pseudomonas aeruginosa strains isolated from burn patients

BACKGROUND

Pseudomonas aeruginosa infections have emerged as a major infectious disease threat in recent decades with infection particularly in immunocompromised hosts. P. aeruginosa possesses several virulence factors with involvement in pathogenesis. The aim of this study was to examine the prevalence of virulence genes of toxA and toxS and to analyze their relation to antimicrobial resistance of the isolates.

METHODS

In total 185 clinical isolates of P. aeruginosa were collected from burn patients. Antimicrobial susceptibility testing was done by disk diffusion method. PCR amplification was performed on extracted DNA from the isolates and the presence of encoding genes for exotoxin A (toxA) and exoenzyme S (toxS) were investigated by using specific primers.

RESULTS

In disk diffusion method, the isolates showed high sensitivity to colistin sulfate (100%) followed by imipenem (41.9%). The most prevalent resistance was seen against ceftazidime (90.5%) and gentamicin (88.5%). Multidrug resistance (MDR) demonstrated in 113 isolates (76.35%). According to PCR amplification, 133 (89.8%) and 127 (85.8%) isolates possessed toxA and toxS genes respectively. The frequencies of genes among MDR strains were 102 (76.6%) for toxA and 98 (77.1%) for toxS. Eighty five MDR isolates possessed both genes (73.9%). The non-MDR strains (23.65%), harbored lower prevalence of simultaneous toxA and toxS genes (26%) compared to MDR strains.

CONCLUSION

The present study established a higher frequency of MDR among P. aeruginosa isolates from burn patients. It was found that the frequency of both toxA &S genes were significantly higher in MDR strains P. aeruginosa strains.