Temporal association between antibiotic use and resistance in Gram-negative bacteria

The β-lactam/lactamase inhibitors (BLBLIs) combination drugs are considered an effective alternative to carbapenems. However, there is a growing concern that the increased use of BLBLIs may lead to increased resistance. This study determined the temporal association between the consumption of BLBLI and the antimicrobial resistance in Gram-negative bacteria. In this retrospective study, electronic data on the Gram-negative bacterial isolates, including A. baumannii, P. aeruginosa, E. coli, and K. pneumoniae from in-patients and susceptibility testing results were retrieved from the medical records of the clinical laboratory. A linear regression and cross-correlation analysis were performed on the acquired data. Increasing trends (p<0.05) in the consumption of BIBLI and carbapenem with a median use of 27.68 and 34.46 DDD/1000 PD per quarter were observed, respectively. A decreased trend (p=0.023) in the consumption of fluoroquinolones with a median use of 29.13 DDD/1000 PD per quarter was observed. The resistance rate of K. pneumoniae was synchronized with the BIBLI and carbapenem consumptions with a correlation coefficient of 0.893 (p=0.012) and 0.951 (p=0.016), respectively. The cross-correlation analysis against the consumption of BIBLI and meropenem resistant K. pneumoniae was peaked at 0-quarter lag (r=951, p=0.016). There was an increasing trend in the consumption of BLBLI and carbapenems. The increasing trend in the rates of resistance to piperacillin/tazobactam, in line with the increasing consumption of BLBLI, suggests that BLBLI has to be used with caution and cannot be directly considered as a long-term alternative to carbapenems.

Evaluation of antibacterial activity of vitamin C against human bacterial pathogens

Now a day’s multidrug resistance phenomenon has become the main cause for concern and there has been an inadequate achievement in the development of novel antibiotics to treat the bacterial infections. Therefore, there is an unmet need to search for novel adjuvant. Vitamin C is one such promising adjuvant. The present study was aimed to elucidate the antibacterial effect of vitamin C at various temperatures (4°C, 37°C and 50°C) and pH (3, 8, and 11), against Gram-positive and Gram-negative bacteria at various concentrations (5-20 mg/ml) through agar well diffusion method. Growth inhibition of all bacterial strains by vitamin C was concentration-dependent. Vitamin C significantly inhibited the growth of Gram-positive bacteria: Bacillus licheniformis (25.3 ± 0.9 mm), Staphylococcus aureus (22.0 ± 0.6 mm), Bacillus subtilis (19.3 ± 0.3 mm) and Gram-negative bacteria: Proteus mirabilis (27.67 ± 0.882 mm), Klebsiella pneumoniae (21.33±0.9 mm), Pseudomonas aeruginosa (18.0 ± 1.5 mm) and Escherichia coli (18.3 ± 0.3 mm). The stability of vitamin C was observed at various pH values and various temperatures. Vitamin C showed significant antibacterial activity at acidic pH against all bacterial strains. Vitamin C remained the stable at different temperatures. It was concluded that vitamin C is an effective and safe antibacterial agent that can be used in the future as an adjunct treatment option to combat infections in humans.

Microbiological characteristics of bloodstream infections in a reference hospital in northeastern Brazil

Routine blood culture is used for the detection of bloodstream infections by aerobic and anaerobic bacteria and by common pathogenic yeasts. A retrospective study was conducted in a public hospital in Maceió-AL, by collecting data of all medical records with positive blood cultures. Out of the 2,107 blood cultures performed, 17% were positive with Staphylococcus coagulase negative (51.14%), followed by Staphylococcus aureus (11.21%) and Klebsiella pneumoniae (6.32%). Gram-positive bacteria predominated among positive blood cultures, highlighting the group of Staphylococcus coagulase-negative. While Gram-negative bacteria had a higher number of species among positive blood cultures.

Anti-microbial resistant in Gram-negative bacteria bacillus: Enterobacteriaceae and non-fermenting bacilli isolated at Sominé DOLO Hospital of Mopti, Mali

Background: β-lactams and carbapenems. are the major antibiotics used to treat gram-negative bacteria and non-fermenting bacilli. However, the increasing production of β-lactamase and carbapenemase limits the therapeutic options. Our study aims to determine the resistant phenotypes of these bacteria while describing their epidemiological aspect. Material and Methods: This was a cross-sectional study by consecutive enrollment from January 2018 to December 2019 at Sominé DOLO Hospital of Mopti, Mali. We performed manual method for bacteria culture, identification and antibiotics sensitivity testing. The antibiotics sensitivity testing was accessed by the diffusion method according to CA-SFM/EUCAST (“Comité de l’Antibiogramme de la Société Française de Microbiologie” / European Committee on Antimicrobial Susceptibility Testing) recommendations V1.0 february 2018 and V2.0 may 2019 2019 V.2.0. May recommendation released in 2019. Data were analyzed by software R 4.0.3 GUI 1.73 Catalina build (7892). Results: At all 904 samples were included in this study. Out of the 904 cultures, 297 sample (32.85%) were positive. The rates of enzymes production were as follow: Extended-spectrum ß-lactamase (ESBL) 56.42% (101/179), cepholosporinase hyperproduction (HCASE) 15.64% (28/179), cephalosporinase production (CASE) 6.14% (11/179), penicillinase hyperproduction (HP) 5.58% (10/179), carbapenemase production (CP) 6.14% (11/179) and savage strains 10.05% (18/179). Conclusion: Our data showed a high prevalence of resistance to β-lactamins ß-talactamins and carbapenemes in gram-negative bacteria and non-fermenting bacillus bacilli. The A high level of β-lactamase and carbapenemase production by gram negative bacillus were also reported by others authors calls for the rational use of antibiotic in hospital setting.

Anti-microbial resistant in Gram-negative bacteria bacillus: Enterobacteriaceae and non-fermenting bacilli isolated at Sominé DOLO Hospital of Mopti, Mali

Background: β-lactams and carbapenems. are the major antibiotics used to treat gram-negative bacteria and non-fermenting bacilli. However, the increasing production of β-lactamase and carbapenemase limits the therapeutic options. Our study aims to determine the resistant phenotypes of these bacteria while describing their epidemiological aspect. Material and Methods: This was a cross-sectional study by consecutive enrollment from January 2018 to December 2019 at Sominé DOLO Hospital of Mopti, Mali. We performed manual method for bacteria culture, identification and antibiotics sensitivity testing. The antibiotics sensitivity testing was accessed by the diffusion method according to CA-SFM/EUCAST (“Comité de l’Antibiogramme de la Société Française de Microbiologie” / European Committee on Antimicrobial Susceptibility Testing) recommendations V1.0 february 2018 and V2.0 may 2019 2019 V.2.0. May recommendation released in 2019. Data were analyzed by software R 4.0.3 GUI 1.73 Catalina build (7892). Results: At all 904 samples were included in this study. Out of the 904 cultures, 297 sample (32.85%) were positive. The rates of enzymes production were as follow: Extended-spectrum ß-lactamase (ESBL) 56.42% (101/179), cepholosporinase hyperproduction (HCASE) 15.64% (28/179), cephalosporinase production (CASE) 6.14% (11/179), penicillinase hyperproduction (HP) 5.58% (10/179), carbapenemase production (CP) 6.14% (11/179) and savage strains 10.05% (18/179). Conclusion: Our data showed a high prevalence of resistance to β-lactamins ß-talactamins and carbapenemes in gram-negative bacteria and non-fermenting bacillus bacilli. The A high level of β-lactamase and carbapenemase production by gram negative bacillus were also reported by others authors calls for the rational use of antibiotic in hospital setting.

Prevalence and characterization of antimicrobial resistance among gram-negative bacteria isolated from febrile hospitalized patients in central Ethiopia

Background Infectious diseases are among the leading causes of death in many low-income countries, such as Ethiopia. Without reliable local data concerning causative pathogens and antimicrobial resistance, empiric treatment is suboptimal. The objective of this study was to characterize gram-negative bacteria (GNB) as pathogens and their resistance pattern in hospitalized patients with infections in central Ethiopia. Methods Patients ≥ 1 year of age with fever admitted to the Asella Referral and Teaching Hospital from April 2016 to June 2018 were included. Blood and other appropriate clinical specimens were collected and cultured on appropriate media. Antibiotic susceptibility testing (AST) was performed using the Kirby–Bauer method and VITEK® 2. Species identification and detection of resistance genes were conducted using MALDI-ToF MS (VITEK® MS) and PCR, respectively. Results Among the 684 study participants, 54.2% were male, and the median age was 22.0 (IQR: 14–35) years. Blood cultures were positive in 5.4% (n = 37) of cases. Among other clinical samples, 60.6% (20/33), 20.8% (5/24), and 37.5% (3/8) of swabs/pus, urine and other body fluid cultures, respectively, were positive. Among 66 pathogenic isolates, 57.6% (n = 38) were GNB, 39.4% (n = 26) were gram-positive, and 3.0% (n = 2) were Candida species. Among the isolated GNB, 42.1% (16/38) were Escherichia coli, 23.7% (9/38) Klebsiella pneumoniae and 10.5% (4/38) Pseudomonas aeruginosa. In total, 27/38 gram-negative isolates were available for further analysis. Resistance rates were as follows: ampicillin/sulbactam, 92.6% (n = 25); cefotaxime, 88.9% (n = 24); ceftazidime, 74.1% (n = 20); cefepime, 74.1% (n = 20); gentamicin, 55.6% (n = 15); piperacillin/tazobactam, 48.1% (n = 13); meropenem, 7.4% (n = 2); and amikacin, 3.7% (n = 1). The blaNDM-1 gene was detected in one K. pneumoniae and one Acinetobacter baumannii isolate, which carried an additional blaOXA-51 gene. The ESBL enzymes were detected in 81.5% (n = 22) of isolates as follows: TEM, 77.2% (n = 17); CTX-M-1 group, 68.2% (n = 15); SHV group, 27.3% (n = 6); and CTX-M-9 group, 9.1% (n = 2). Based on the in vitro antimicrobial susceptibility results, empiric treatment initiated in 13 of 18 (72.2%) patients was likely ineffective. Conclusion We report a high prevalence of ESBL-producing bacteria (81.5%) and carbapenem resistance (7.4%), with more than half of GNB carrying two or more ESBL enzymes resulting in suboptimal empiric antibiotic therapy. These findings indicate a need for local and national antimicrobial resistance surveillance and the strengthening of antimicrobial stewardship programs.

Pathogenic characteristics of pulmonary infection in hospitalized patients with chronic heart failure and diagnostic value of sTREM-1, sCD163, and sTWEAK

Objective: To investigate the pathogenic characteristics of pulmonary infection in hospitalized patients with chronic heart failure as well as the diagnostic value of soluble myeloid cell expression triggering receptor-1 (sTREM-1), soluble CD163 (sCD163) and soluble tumor necrosis factor-like weak inducing factor (sTWEAK). Methods: A total of 72 patients with pulmonary infection who were hospitalized with chronic heart failure from December 2017 to December 2019 in the Department of Cardiology of Hebei Baoding Huaying Hospital of Traditional Chinese Medicine, China, were selected as the infection group, seventy-two patients without pulmonary infection who were hospitalized with chronic heart failure were selected as the non-infection group, and 50 healthy subjects who underwent physical examination in the hospital during the same period were selected as the control group. The distribution characteristics of pathogens in the infection group were statistically analyzed. The levels of sTREM-1, S CD163 and STweak in serum of patients with different infection severity and different cardiac function grades were compared among the three groups. Receiver operating characteristic curve (ROC) was utilized to evaluate the predictive value of the three indicators for the adverse prognosis of patients in hospital. Results: A total of 76 strains of pathogens were cultured from two hospitalized patients with pulmonary infection of chronic heart failure, among which 43 strains (56.58%) were gram-negative bacteria, 29 strains (38.15%) were gram-positive bacteria, and four strains (5.26%) were fungi. The levels of sTREM-1 and sCD163 in the control group, non-infection group and infection group were gradually increased (p<0.05), while there was no difference in sTWEAK between the infection group and the non-infection group (p>0.05). In the infection group, the expression levels of sTREM-1 and sCD163 increased with the severity of infection, with statistically significant differences (p<0.05), while there was no statistically significant difference in the expression level of sTWEAK among different infection severity (p>0.05). The higher the cardiac function grade of patients in the infection group, the higher the levels of sTREM-1 and sCD163, and the lower the level of sTWEAK, with a statistical significance (p<0.05). ROC analysis results showed that the serum sTREM-1, sCD163, and sTWEAK levels for the poor prognosis of patients with CHF combined with lung infection had areas under the curve of 0.864, 0.870, and 0.822, respectively, and the 95% CI values were 0.787-0.941, 0.795-0.945 and 0.733-0.910, respectively, all p<0.001. Conclusions: Pulmonary infection in hospitalized patients with chronic heart failure is mainly caused by gram-negative bacteria. Detection of sTREM-1, sCD163, and sTWEAK levels is of certain value in judging the condition and prognosis, which is worthy of clinical promotion. doi: https://doi.org/10.12669/pjms.38.3.4758 How to cite this:Zheng F. Pathogenic characteristics of pulmonary infection in hospitalized patients with chronic heart failure and diagnostic value of sTREM-1, sCD163, and sTWEAK. Pak J Med Sci. 2022;38(3):---------. doi: https://doi.org/10.12669/pjms.38.3.4758 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Efficient Genome Editing by a Miniature CRISPR-AsCas12f1 Nuclease in Bacillus anthracis

A miniature CRISPR-Cas12f has been demonstrated to serve as an effective genome editing tool in gram negative bacteria as well as human cells. Here, we developed an alternative method to edit the genome of Bacillus anthracis based on the AsCas12f1 nuclease from Acidibacillus sulfuroxidans. When the htrA gene on the chromosome and the lef gene on the plasmid pXO1 were selected as targets, the CRISPR-AsCas12f1 system showed very high efficiency (100%). At the same time, a high efficiency was observed for large-fragment deletion. Our results also indicated that the length of the homologous arms of the donor DNA had a close relationship with the editing efficiency. Furthermore, a two-plasmid CRISPR-AsCas12f1 system was also constructed and combined with the endonuclease I-SceI for potential multi-gene modification. This represents a novel tool for mutant strain construction and gene function analyses in B. anthracis and other Bacillus cereus group bacteria.

Gas Chromatographic analysis of potentially bioactive compounds in leaf and root extracts of Muntingia calabura and their expected antibacterial activities

The study aimed to identify bioactive compounds in <i>Muntingia calabura</i> leaf and root methanolic extracts. The Gas Chromatography and Mass Spectroscopy (GC-MS) technique were used to identify bioactive compounds. GC-MS analysis revealed 38 compounds in the leaf and 15 compounds in the root methanolic extracts of <i>M. calabura</i>. The prime potent compound found in leaf extract is 2-{3-[(E)-2-(1H-indol-3-yl)ethenyl]-1,2,4-oxadiazol-5-yl}phenol with 5.78% peak area and cholest-4-en-6-on-3-ol is found in root extracts, has the highest 63.7% peak area and another potent compound Lupeol has 7.3% peak area. The bioactive compounds identified in <i>M. calabura</i> have antibacterial activity against various bacterial strains such as gram-positive and gram-negative bacteria, which showed the efficacy of <i>in vivo</i> plant extracts. These findings validate the therapeutic potentiality of <i>M. calabura</i> leaf and root samples. Furthermore, these screened potential bioactive compounds can be used effectively for biomedical and therapeutic applications.

Plethora of Resistance Genes in Carbapenem-Resistant Gram-Negative Bacteria in Greece: No End to a Continuous Genetic Evolution

Carbapenem-resistant Gram-negative bacteria are a public health threat that requires urgent action. The fact that these pathogens commonly also harbor resistance mechanisms for several other antimicrobial classes further reduces patient treatment options. The present study aimed to provide information regarding the multidrug resistance genetic background of carbapenem-resistant Gram-negative bacteria in Central Greece. Strains from a tertiary care hospital, collected during routine practice, were characterized using a DNA microarray-based assay. Various different resistance determinants for carbapenems, other beta-lactams, aminoglycosides, quinolones, trimethoprim, sulfonamides and macrolides were detected among isolates of the same sequence type. Eighteen different multidrug resistance genomic profiles were identified among the twenty-four K. pneumoniae ST258, seven different profiles among the eight K. pneumoniae ST11, four profiles among the six A. baumannii ST409 and two among the three K. oxytoca. This report describes the multidrug resistance genomic background of carbapenem-resistant Gram-negative bacteria from a tertiary care hospital in Central Greece, providing evidence of their continuous genetic evolution.