Number Of Resistant Bacteria Research Articles

Association of short-course antimicrobial therapy and bacterial resistance in acute cholangitis: Retrospective cohort study.

Background and study aims Although the number of resistant bacteria tends to increase with prolonged antimicrobial therapy, no studies have examined the relationship between the duration of antimicrobial therapy and increase in the number of resistant bacteria in acute cholangitis. We hypothesized that the short-term administration of antimicrobial agents in acute cholangitis would suppress bacterial resistance. Patients and methods This was a single-center, retrospective, observational study of patients with acute cholangitis admitted between January 2018 and June 2020 who met the following criteria: successful biliary drainage, positive blood or bile cultures, bacteria identified from cultures sensitive to antimicrobials, and subsequent cholangitis recurrence by January 2022. The patients were divided into two groups: those whose causative organisms at the time of recurrence became resistant to the antimicrobial agents used at the time of initial admission (resistant group) and those who remained susceptible (susceptible group). Multivariate analysis was used to examine risk factors associated with the development of resistant pathogens. Multivariate analysis investigated antibiotics used with the length of 3 days or shorter after endoscopic retrograde cholangiopancreatography (ERCP) and previously reported risk factors for the development of bacterial resistance. Results In total, 89 eligible patients were included in this study. There were no significant differences in patient background or ERCP findings between the groups. The use of antibiotics, completed within 3 days after ERCP, was associated with a lower risk of developing bacterial resistance (odds ratio, 0.17; 95% confidence interval, 0.04-0.65; P =0.01). Conclusions In acute cholangitis, the administration of antimicrobials within 3 days of ERCP may suppress the development of resistant bacteria.

Persistent effects of intramammary ceftiofur treatment on the gut microbiome and antibiotic resistance in dairy cattle

BackgroundIntramammary (IMM) ceftiofur treatment is commonly used in dairy farms to prevent mastitis, though its impact on the cattle gut microbiome and selection of antibiotic-resistant bacteria has not been elucidated. Herein, we enrolled 40 dairy (Holstein) cows at the end of the lactation phase for dry-cow therapy: 20 were treated with IMM ceftiofur (Spectramast®DC) and a non-antibiotic internal teat sealant (bismuth subnitrate) and 20 (controls) received only bismuth subnitrate. Fecal grab samples were collected before and after treatment (weeks 1, 2, 3, 5, 7, and 9) for bacterial quantification and metagenomic next-generation sequencing.ResultsOverall, 90% and 24% of the 278 samples had Gram-negative bacteria with resistance to ampicillin and ceftiofur, respectively. Most of the cows treated with ceftiofur did not have an increase in the number of resistant bacteria; however, a subset (25%) shed higher levels of ceftiofur-resistant bacteria for up to 2 weeks post-treatment. At week 5, the antibiotic-treated cows had lower microbiota abundance and richness, whereas a greater abundance of genes encoding extended-spectrum β-lactamases (ESBLs), CfxA, ACI-1, and CMY, was observed at weeks 1, 5 and 9. Moreover, the contig and network analyses detected associations between β-lactam resistance genes and phages, mobile genetic elements, and specific genera. Commensal bacterial populations belonging to Bacteroidetes most commonly possessed ESBL genes followed by members of Enterobacteriaceae.ConclusionThis study highlights variable, persistent effects of IMM ceftiofur treatment on the gut microbiome and resistome in dairy cattle. Antibiotic-treated cattle had an increased abundance of specific taxa and genes encoding ESBL production that persisted for 9 weeks. Fecal shedding of ESBL-producing Enterobacteriaceae, which was classified as a serious public health threat, varied across animals. Together, these findings highlight the need for additional studies aimed at identifying factors associated with shedding levels and the dissemination and persistence of antibiotic resistance determinants on dairy farms across geographic locations.

“Antimicrobial resistance in fowl production: cutting-edge status and innovative strategies for bacterial manipulate”

The significant increase in the world population has also led to an increase in the Consumption of poultry products, which must meet certain requirements while maintaining Their quality and safety. It is known that in animal production, including poultry, antibiotics (Antibiotics) are used as preventive measures to prevent or treat infectious diseases. Unfortunately, the use and abuse of these compounds has led to the development and Dissemination of antibiotics, which is a major public health problem today. The number of Resistant bacteria is increasing and causing serious harm to humans and animals; Therefore, The aim of this review is to discuss the formation of antibiotics in poultry, focusing on the Current situation in the agricultural sector. New disease control strategies based on research Used in this sector are also described.

Quiescence of Escherichia coli Aerosols to Survive Mechanical Stress during High-Velocity Collection.

A low cutpoint wetted wall bioaerosol sampling cyclone (LCP-WWC), with an aerosol sampling flow rate of 300 L/min at 55″ H2O pressure drop and a continuous liquid outflow rate of about 0.2 mL/min, was developed by upgrading an existing system. The laboratory strain Escherichia coli MG1655 was aerosolized using a six-jet Collison Nebulizer and collected at high velocity using the LCP-WWC for 10 min with different collection liquids. Each sample was quantitated during a 15-day archiving period after aerosolization for culturable counts (CFUs) and gene copy numbers (GCNs) using microbial plating and whole-cell quantitative polymerase chain (qPCR) reaction. The samples were analyzed for protein composition and antimicrobial resistance using protein gel electrophoresis and disc diffusion susceptibility testing. Aerosolization and collection were followed by an initial period of quiescence or dormancy. After 2 days of archiving at 4 °C and RT, the bacteria exhibited increased culturability and antibiotic resistance (ABR), especially to cell wall inhibitors (ampicillin and cephalothin). The number of resistant bacteria on Day 2 increased nearly four-times compared to the number of cells at the initial time of collection. The mechanical stress of aerosolization and high-velocity sampling likely stunned the cells triggering a response of dormancy, though with continued synthesis of vital proteins for survival. This study shows that an increase in intensity in environmental conditions surrounding airborne bacteria affects their ability to grow and their potential to develop antimicrobial resistance.

Erythrocyte membrane-camouflaged nanoworms with on-demand antibiotic release for eradicating biofilms using near-infrared irradiation

The increase in the number of resistant bacteria caused by the abuse of antibiotics and the emergence of biofilms significantly reduce the effectiveness of antibiotics. Bacterial infections are detrimental to our life and health. To reduce the abuse of antibiotics and treat biofilm-related bacterial infections, a biomimetic nano-antibacterial system, RBCM-NW-G namely, that controls the release of antibiotics through near infrared was prepared. The hollow porous structure and the high surface activity of nanoworms are used to realize antibiotic loading, and then, biomimetics are applied with red blood cell membranes (RBCM). RBCM-NW-G, which retains the performance of RBCM, shows enhanced permeability and retention effects. Fluorescence imaging in mice showed the effective accumulation of RBCM-NW-G at the site of infection. In addition, the biomimetic nanoparticles showed a longer blood circulation time and good biocompatibility. Anti-biofilm test results showed damage to biofilms due to a photothermal effect and a highly efficient antibacterial performance under the synergy of the photothermal effect, silver iron, and antibiotics. Finally, by constructing a mouse infection model, the great potential of RBCM-NW-G in the treatment of in vivo infections was confirmed.

Antibiotic-Resistant Bacteria in Hydroponic Lettuce in Retail: A Comparative Survey.

Hydroponic produce is gaining popularity due to its suitability for urban agriculture. The general public also considers that hydroponic produce is free from microbiological contamination. In this study, we compared the frequency and abundance of tetracycline-resistant and sulphadiazine-resistant bacteria and the minimal inhibitory concentration (MIC) of these isolates in conventional, organic, and hydroponic lettuce sold in retail. We also determined the frequency of samples carrying tetB, tetX, sul1, sul2, and int1 genes by PCR and further quantified the copy number of tetX, sul1, and int1 genes in samples positive for these genes using qPCR. As expected, the number of resistant bacteria and the MICs of these isolates were lowest in hydroponic lettuce and highest in organic lettuce. All tested resistant genes, except int1, were detected in samples of all three production methods, but no significant difference was observed between the three groups in the frequency of samples carrying the resistance genes examined or in their copy number. To the best of our knowledge, it is the first study directly reporting the existence of antibiotic-resistant bacteria and resistance genes in hydroponic vegetables sold in retail. The result highlights that the risk of antibiotic-resistant bacteria contamination in hydroponic produce should be further investigated.

In vitro photoinactivation of bovine mastitis related pathogens

BackgroundBovine mastitis is considered the most important disease of worldwide dairy industry. Treatment of this disease is based on the application intramammary antibiotic, which favors an increase in the number of resistant bacteria in the last decade. Photodynamic inactivation (PDI) has been investigated in different areas of Health Sciences, and has shown great potential for inactivating different pathogens, without any selection of resistant microorganisms. The objective of this study was to investigate the efficacy of PDI in the inactivation of pathogens associated with bovine mastitis. MethodsWe tested the effectiveness of PDI against antibiotic resistant strains, isolated from bovine mastitis, from the following species: Staphylococcus aureus, Streptococcus agalactiae, Streptococcus dysgalactiae, Corynebacterium bovis, and the alga Prototheca zopfii. Nine experimental groups were evaluated: control, no treatment; light only, irradiation of a red light-emitting diode (λ=662 (20) nm) for 180s; exposure to 50μM methylene blue alone for 5min; and PDI for 5, 10, 30, 60, 120 and 180s. ResultsS. dysgalactiae, S. aureus, and C. bovis were inactivated after 30s of irradiation, whereas S. agalactiae was inactivated after 120s and P. zopfii at 180s of irradiation. ConclusionThese results show that PDI can be an interesting tool for inactivating pathogens for bovine mastitis.

Utilization of Fenton-like reaction for antibiotics and resistant bacteria elimination in different parts of WWTP

Utilization of relatively low-cost modification of Fenton reaction for the elimination of selected antibiotics and resistant coliforms in different part of wastewater treatment plant (WWTP) was studied. The concentration of antibiotics and occurrence of resistant gems in different stages of WWTP in the capital city of Slovakia – Bratislava was analyzed by LC–MS/MS technique. Consequently, Fenton-like reaction was applied for the elimination of chemical and biological contaminants. Comparative study with classical Fenton reaction was also done. Very high concentrations of clarithromycin, ciprofloxacin and azithromycin in influent water were found. Coliform bacteria were predominantly resistant to ampicillin, ciprofloxacin and gentamicin. After the mechanical stage, the concentration of antibiotics in water was significantly decreased because of the sorption during this step. Biological step degraded 12 types of antibiotics. Analyses of effluent water showed very bad elimination of azithromycin (919ng/L) and clarithromycin (684ng/L). Contrary, ciprofloxacin was removed with very high efficiency (95%). The number of resistant bacteria was also significantly decreased in effluent water. In the case of Escherichia coli only ampicillin and gentamicin resistance bacteria were detected. Our results show that antibiotics as well as resistant bacteria were eliminated by the modification of classical Fenton reaction with high efficiency. The modification of the Fenton reaction can decrease the process wages, environmental impact. Moreover, the degradation process was easily controlled, monitored and tuned.

Defensins: Natural component of human innate immunity

The widespread use of antibiotics has contributed to a huge increase in the number of resistant bacteria. New classes of drugs are therefore being developed of which defensins are a potential source. Defensins are a group of antimicrobial peptides found in different living organisms, involved in the first line of defense in their innate immune response against pathogens. This review summarizes the results of studies of this family of human antimicrobial peptides (AMPs). There is a special emphasis on describing the entire group and individual peptides, history of their discovery, their functions and expression sites. The results of the recent studies on the use of the biologically active peptides in human medicine are also presented. The pharmaceutical potential of human defensins cannot be ignored, especially considering their strong antimicrobial activity and properties such as low molecular weight, reduced immunogenicity, broad activity spectrum and resistance to proteolysis, but there are still many challenges and questions regarding the possibilities of their practical application.

Protecting the antibiotic miracle

A combination of infection control measures, improved sanitation, and antibiotics have rendered some infections feared by our ancestors manageable. However, the growing number of resistant bacteria threatens the antibiotic miracle. Bacteria can become resistant to antibiotics in numerous ways. Bacteria may employ alternative metabolic pathways to bypass the disruption caused by an antibiotic. They do this by secreting enzymes that destroy antibiotics or altering cell wall composition. In general, bacteria acquire these resistance mechanisms through changes to their genetic code, offering an example of natural selection in action. Spontaneous chromosomal mutations occur once in 100 million microorganisms, but the enormous numbers of bacteria in the human body means that the absolute number of mutations is relatively high, providing ample opportunity for a bacterial strain to acquire antibiotic resistance. This article explains how genetic resistance to antibiotics develops in bacteria, and how nurses can help reduce the emergence of ‘super’ bacterial strains resistant to common antibiotics.

Antibiotic Resistance: Who Will Pay the Bills?

Antibiotic Resistance: Who Will Pay the Bills?

In vivo induction of resistance to macrolide antibiotics in staphylococci with erythromycin.

In vivo induction of resistance to macrolide (Mac) antibiotics was investigated using mice infected with Staphylococcus aureus MS537 followed by treatment with either erythromycin (EM) or josamycin (JM). An EM-inducible strain MS537, in which only EM was an active inducer for Mac resistance, acquired in vivo resistance to both Mac antibiotics and lincomycin (LCM) 2 hr after an EM injection but the resistance of the induced cells was lost 2 days thereafter. Consequently, EM was found to have no therapeutic effect on MS537 infection and the number of resistant bacteria recovered from the kidney increased even after 6 intraperitoneal injections of 0.2 nig each of EM; the number of bacteria recovered from the kidney showing the same level as the controls without treatment. JM, one of the non-inducers for Mac resistance, by contrast, showed a therapeutic effect on MS537 infection and the number of organisms recovered from the kidney decreased to one-thousandth of that obtained with EM treatment, resulting in the survival of mice.