Changes In Bacterial Resistance Research Articles

Effect of exposure to sub-inhibitory concentrations of biocides on the susceptibility to antibiotics of sessile cells of Listeria monocytogenes and Salmonellaenterica

The effect of sub-inhibitory concentrations of several disinfectants on the antibiotic resistance of sessile cells of Listeria monocytogenes and Salmonella enterica was investigated. Biofilms were formed in the presence of biocides at MIC/2. Five compounds were used: peracetic acid (PAA), benzalkonium chloride (BZK), sodium hypochlorite (SHY), polyvinyl pyrrolidone iodine (PVI) and bis(3-aminopropyl)amine (BAPA). Two strains of L. monocytogenes (LM30 and LM28) and S. enterica (S. Typhimurium -ST- and S. Enteritidis -SE-) were used. Mono-species biofilms (MSB) and mixed biofilms (MB, LM30 + ST and LM28 + SE) were tested. LM30 went from susceptible to resistant to tetracycline and erythromycin after exposure to BAPA in MB. LM28 went from susceptible to resistant to tetracycline in the presence of PVI in MSB, from susceptible to intermediate to chloramphenicol after exposure to PAA in both MSB and MB, from susceptible to resistant to erythromycin after exposure to BAPA in MB, and from susceptible to resistant to ampicillin after exposure to SHY and BAPA in MB. ST went from intermediate to resistant to gentamicin after exposure to SHY, PVI and BAPA (MSB), or to PVI and BAPA (MB). This strain went from susceptible to intermediate to cefoxitin after exposure to BZK and PVI (MSB) or to BZK, PVI and BAPA (MB). For fosfomycin, ST went from susceptible to intermediate after exposure to PAA, PVI and BAPA (MSB) or to SHY, BZK, PVI and BAPA (MB). In the case of cephalothin, ST moved from intermediate to resistant category in MSB exposed to BAPA. SE moved from susceptible to intermediate to cefoxitin after contact with PAA in both MSB and MB. By contrast, in several occasions, strains increased their susceptibility to antibiotics after exposure to biocides. In some additional cases, contact with disinfectants caused significative modifications in the MIC of various antibiotics without the strains changing from one category to another. These findings show that contact with low concentrations of biocides can modify the antibiotic resistance of sessile cells of L. monocytogenes and S. enterica. The need to use adequate doses of disinfectants in food facilities in order to avoid changes in bacterial resistance is highlighted.

Bacterial resistance in urine cultures during a decade

Introduction: Bacterial resistance to antibiotics is a global problem; Due to its great variability, each hospital should carry out its own microbiological surveillance. Objective: To identify changes in bacterial resistance in urine cultures with Gram-negative isolation from the urology department over a decade. Material and methods: Analytical, retrospective cross-sectional study, 1072 urine cultures requested by the urology department of Hospital Juárez de México were collected between 6/01/2012 and 5/31/2022. The percentage of resistance by germ and antibiotic was divided into three periods: initial, intermediate and final to compare with X2 trends. According to the sensitivity report, high resistance >16 and high sensitivity ≤2 were defined. Statistical analysis was performed using IBM SPSS V.25 software and Epi Info Companion V.5.5.10 software. Results: For a decade, the urology service of Hospital Juárez de México has a total of 1072 records in the database, initial date 6/01/2012 and end date 06/01/2022. The most frequent germs were Escherichia coli 709 (66 %), Klebsiella pneumoniae 61 (6 %) and Pseudomonas aeruginosa 56 (5 %). The majority of antibiotics showed persistence in the percentage of resistance. Amoxicillin with clavulanate had a significant decrease (X2 Tend=13.17, p=0.0003). Cefepime (X2 Tend=4.84, p=0.027) and amikacin (X2 Tend=5.76, p=0.016) had a slight significant increase. Cefazolin (X2 Tend=5.00, p=0.025), Levofloxacin (X2 Tend=7.81, p=0.005), Ceftazidime (X2 Tend=3.74, p=0.05) significantly increased the percentage of resistance. Conclusion: Dividing the patterns of bacterial resistance by uropathogens, family of antibiotics, levels of resistance and sensitivity, improves knowledge and favors a better selection of treatments in the population attended by the urology service of the Hospital Juárez de México.

Update About The Changes In Bacterial Resistance For Multiple Antibiotic In Patients With Urinary Tract Infection In Kerbala

Urinary tract infections (UTIs) caused by Escherichia coli (E. coli) are common and recurrent, particularly among females. Treatment often involves various antimicrobial agents, but rising resistance poses challenges. We conducted a study in Al-Hussein Medical City, Kerbala, enrolling 520 UTI patients from April 2022 to February 2023. Urine samples were tested for antimicrobial susceptibility. Results showed high resistance to most agents, except meropenem and levofloxacin. Our findings emphasize the urgent need for strategies to combat antimicrobial resistance in UTIs. Highlights: High resistance in UTI treatment observed. Urgent need for antimicrobial resistance strategies. Study reveals E. coli resistance patterns in Kerbala's medical setting. Keywords: Urinary tract infections, Escherichia coli, Antimicrobial resistance, Al-Hussein Medical City, Kerbala

BacteSign: Building a Findable, Accessible, Interoperable, and Reusable (FAIR) Database for Universal Bacterial Identification.

With the increasing incidence of diverse global bacterial outbreaks, it is important to build an immutable decentralized database that can capture regional changes in bacterial resistance with time. Herein, we investigate the use of a rapid 3D printed µbiochamber with a laser-ablated interdigitated electrode developed for biofilm analysis of Pseudomonas aeruginosa, Acinetobacter baumannii and Bacillus subtilis using electrochemical biological impedance spectroscopy (EBIS) across a 48 h spectrum, along with novel ladder-based minimum inhibitory concentration (MIC) stencil tests against oxytetracycline, kanamycin, penicillin G and streptomycin. Furthermore, in this investigation, a search query database has been built demonstrating the deterministic nature of the bacterial strains with real and imaginary impedance, phase, and capacitance, showing increased bacterial specification selectivity in the 9772.37 Hz range.

Bacterial etiology and antimicrobial resistance pattern of pediatric bloodstream infections: a 5-year experience in an Iranian referral hospital

BackgroundBloodstream infections (BSI) are the major cause of morbidity and mortality in children in developing countries. The purpose of the current study was to establish the antimicrobial susceptibility pattern of bacterial isolates from bloodstream infections at Children’s Medical Center Hospital (CMC), Tehran, Iran.MethodsWe retrospectively recorded all positive blood cultures and antimicrobial susceptibility of all bloodstream isolates among children admitted to CMC, during 5 years. Specimen culture, bacterial identification, and antimicrobial susceptibility testing were performed according to standard laboratory methods.ResultsFrom 3,179 pathogens isolated from the blood cultures 2,824 bacteria were cultured, with 1,312 cases being identified as Gram-positive bacteria (46%) and 1,512 cases as Gram-negative bacteria (54%). The most common Gram-negative bacteria isolated were as follows: Pseudomonas spp. (n = 266, 17.6%), Klebsiella pneumoniae (n = 242, 16%), Stenotrophomonas maltophilia (n = 204, 13.5%), Enterobacter spp. (n = 164, 10.8%), Escherichia coli (n = 159, 10.5%), Pseudomonas aeruginosa (n = 126, 8.3%), Serratia marcescens (n = 121, 8%), and Acinetobacter baumannii (n = 73, 4.8%). The most common Gram-positive bacteria isolated were coagulase-negative staphylococci (CONS) (n = 697, 53%), Streptococcus spp. (n = 237, 18%), Staphylococcus aureus (n = 202, 15%) and Enterococcus spp. (n = 167, 12.7%). 34% of bacterial strains were isolated from ICUs. The rates of methicillin resistance in S. aureus and CONS were 34% and 91%, respectively. E. coli isolates showed high resistance to cefotaxime (84%). All isolates of K. pneumoniae were susceptible to colistin and 56% were susceptible to imipenem. P. aeruginosa isolates showed high susceptibility to all antibiotics.ConclusionsOur findings emphasize the need of clinicians having access to up-to-date bacterial susceptibility data for routinely prescribed drugs. Continuous monitoring of changes in bacterial resistance will aid in the establishment of national priorities for local intervention initiatives in Iran. The increased risk of BSI caused by antibiotic-resistant organisms, emphasizes the significance of implementing appropriate antibiotic prescribing regulations and developing innovative vaccination techniques in Iran.

248 U.S. Challenges with E. Coli and Road map for the Future

Abstract In recent years U.S pork producers have been faced with what seems to be a never-ending uphill battle, with Enterotoxigenic E. coli which causes severe post weaning diarrhea and mortality. Numerous hypotheses ranging from pig genetics to changes in bacterial resistance have all been discussed as potential causes, but no clear answer has been provided to date. Over the past two years, many nutritional strategies (low crude protein, higher fiber diets, etc.) aimed at mitigating the deleterious effects of ETEC have been tried in both field and research nurseries with varying success. There is a concerted effort across the industry to better understand E. coli and possible mitigation and prevention strategies. However, to be successful we need to understand that controlling E. coli is a multidisciplinary issue that requires understanding how each piece of the puzzle impacts E. coli. Production practices, veterinarian protocols, stress events (weaning, transportation), temperature, and clear plans for a world post pharmacological levels of zinc and feed grade medications all contribute to the success of mitigating/eliminating ETEC. While the pig demands we find solutions quickly, the sustainability of healthy swine production and lower production cost require us to find the root source. This requires starting at the beginning of the process and piecing the puzzle together. We need research at all levels of production to understand key triggers–actions and reactions. What things are we doing in the farrowing crate today that impacts this? When pigs are placed in the nursery, what is the required temperature for newly weaned pigs? Are there possibly production practices that have benefits in one place and harsh impacts in another? These are examples of questions needing answered. To fix an issue of this magnitude, you must understand it simply – and we simply do not understand this issue well enough today.

Bacterial Resistance to Antibiotics and Clonal Spread in COVID-19-Positive Patients on a Tertiary Hospital Intensive Care Unit, Czech Republic.

This observational retrospective study aimed to analyze whether/how the spectrum of bacterial pathogens and their resistance to antibiotics changed during the worst part of the COVID-19 pandemic (1 November 2020 to 30 April 2021) among intensive care patients in University Hospital Olomouc, Czech Republic, as compared with the pre-pandemic period (1 November 2018 to 30 April 2019). A total of 789 clinically important bacterial isolates from 189 patients were cultured during the pre-COVID-19 period. The most frequent etiologic agents causing nosocomial infections were strains of Klebsiella pneumoniae (17%), Pseudomonas aeruginosa (11%), Escherichia coli (10%), coagulase-negative staphylococci (9%), Burkholderia multivorans (8%), Enterococcus faecium (6%), Enterococcus faecalis (5%), Proteus mirabilis (5%) and Staphylococcus aureus (5%). Over the comparable COVID-19 period, a total of 1500 bacterial isolates from 372 SARS-CoV-2-positive patients were assessed. While the percentage of etiological agents causing nosocomial infections increased in Enterococcus faecium (from 6% to 19%, p < 0.0001), Klebsiella variicola (from 1% to 6%, p = 0.0004) and Serratia marcescens (from 1% to 8%, p < 0.0001), there were significant decreases in Escherichia coli (from 10% to 3%, p < 0.0001), Proteus mirabilis (from 5% to 2%, p = 0.004) and Staphylococcus aureus (from 5% to 2%, p = 0.004). The study demonstrated that the changes in bacterial resistance to antibiotics are ambiguous. An increase in the frequency of ESBL-positive strains of some species (Serratia marcescens and Enterobacter cloacae) was confirmed; on the other hand, resistance decreased (Escherichia coli, Acinetobacter baumannii) or the proportion of resistant strains remained unchanged over both periods (Klebsiella pneumoniae, Enterococcus faecium). Changes in pathogen distribution and resistance were caused partly due to antibiotic selection pressure (cefotaxime consumption increased significantly in the COVID-19 period), but mainly due to clonal spread of identical bacterial isolates from patient to patient, which was confirmed by the pulse field gel electrophoresis methodology. In addition to the above shown results, the importance of infection prevention and control in healthcare facilities is discussed, not only for dealing with SARS-CoV-2 but also for limiting the spread of bacteria.

Antibiotic resistance is common in the cultures of intraabdominal abscess drainage after appendectomy

IntroductionIntraabdominal abscesses (IAA) are a common complication following appendectomy. Empiric antibiotic regimens may fail to prevent IAA due to changes in bacterial resistance. We aim to describe the bacteriology of pediatric patients requiring drainage of an IAA after an appendectomy for appendicitis. MethodsWe performed a retrospective study of patients ≤18 years who underwent percutaneous drainage of an IAA following appendectomy a single U.S. children's hospital between 2015 and 2018. Patient demographics, appendicitis characteristics, antibiotic regimens, and culture data were collected. ResultsIn total, 71 patients required drainage of an IAA of which 48 (67%) were male, the average age was 9.81 (SD 3.31) years and 68 (95.7%) having complicated appendicitis. Ceftriaxone/metronidazole was the most common empiric regimen prior to IAA drainage occurring in 64 (90.1%) patients. IAA cultures isolated organisms in 34 (47.9%) patients. Of those with positive cultures, 17 (50%) cases demonstrated an antimicrobial resistant organism. Most notably, 20% of Escherichia coli was resistant to the empiric regimen. Empiric antimicrobial regimens did not appropriately cover 92.3% of Pseudomonas aeruginosa cultures or 100% of Enterococcus species cultures. Antimicrobial regimens were changed following IAA drainage in 30 (42.2%) instances with 23 (32.4%) instances due to resistance in culture results or lack of appropriate empiric antimicrobial coverage. ConclusionsIAA culture data following appendectomy for appendicitis frequently demonstrates resistance to or lack of appropriate coverage by empiric antimicrobial regimens. These data support close review of IAA culture results to identify prevalent resistant pathogens along with local changes in resistance. Level of evidenceLevel III

A novel concentration gradient microfluidic chip for high-throughput antibiotic susceptibility testing of bacteria.

Antibiotic resistance has become a serious threat to food safety and public health globally. Therefore, the development of a sensitive, quick, and simple method for antibiotic susceptibility testing is an urgent and crucial need. A novel concentration gradient microfluidic chip was designed in this work to generate antibiotic concentration gradient, culture bacteria, and produce fluorescence emission. An in-house-assembled fluorescence detection platform was constructed, and experiments were conducted to verify the linearity of the generated concentration gradient, explore the appropriate incubation time and flow rate for the microfluidic chip, and study the effect of long-term acid-based food processing on antibiotic susceptibility testing. Experimental results show that the concentration gradient generated by the microfluidic chip exhibited good linearity, stability, and controllability. The appropriate flow rate and incubation time for the microfluidic chip were 2μL/min and 5 h, respectively. The use of this microfluidic chip for testing antibiotic resistance of Salmonella to ofloxacin and ampicillin generated results that were completely consistent with test results obtained using the gold-standard method. Furthermore, Salmonella showed greater sensitivity to antibiotics under strong acid conditions, confirming the potential influence of acid-based food processing on antibiotic susceptibility testing of real samples. The designed microfluidic chip provides a high-throughput, sensitive, and rapid antibiotic susceptibility testing method that combines the microfluidic chip and the fluorescence detection platform. The application of this method would facilitate determination of antibiotic-resistant bacterial strains for clinicians and researchers, and enable monitoring of changes in bacterial resistance during food processing.

A computational model to monitor and predict trends in bacterial resistance.

Current concern over the emergence of multidrug-resistant superbugs has renewed interest in approaches that can monitor existing trends in bacterial resistance and make predictions of future trends. Recent advances in bacterial surveillance and the development of online repositories of susceptibility tests across wide geographical areas provide an important new resource, yet there are only limited computational tools for its exploitation. Here we propose a hybrid computational model called BARDmaps for automated analysis of antibacterial susceptibility tests from surveillance records and for performing future predictions. BARDmaps was designed to include a structural computational model that can detect patterns among bacterial resistance changes as well as a behavioural computational model that can use the detected patterns to predict future changes in bacterial resistance. Data from the European Antimicrobial Resistance Surveillance Network (EARS-Net) were used to validate and apply the model. BARDmaps was compared with standard curve-fitting approaches used in epidemiological research. Here we show that BARDmaps can reliably predict future trends in bacterial resistance across Europe. BARDmaps performed better than other curve-fitting approaches for predicting future resistance levels. In addition, BARDmaps was also able to detect abrupt changes in bacterial resistance in response to outbreaks and interventions as well as to compare bacterial behaviour across countries and drugs. In conclusion, BARDmaps is a reliable tool to automatically predict and analyse changes in bacterial resistance across Europe. We anticipate that BARDmaps will become an invaluable tool both for clinical providers and governmental agencies to help combat the threat posed by antibiotic-resistant bacteria.

Socioeconomic determinants of outpatient antibiotic use in Europe

ObjectivesOutpatient antibiotic consumption widely varies across Europe. The investigation of the causes of such variation may help to identify interventions that would improve the efficient use of antibiotics. The aim of this study was to assess the impact of socioeconomic determinants and the role played by information about bacterial resistance.MethodsComparable data on systemically administered antibiotics and socioeconomic determinants in 17 European countries were available between 2000 and 2005. We estimated an ad hoc econometric model by means of a hybrid log–log functional form and random effects generalised least squares regressions. Lagged values and the instrumental variable method were applied to address endogeneity of bacterial resistance and infections. Bacterial resistance was measured by the rate of penicillin non-susceptible Streptococcus pneumoniae isolates (PNSP) and methicillin-resistant Staphylococcus aureus (MRSA).ResultsThe population income, demographic structure, density of general practitioners and their remuneration method appeared to be significant determinants of antibiotic consumption. Although countries with higher levels of bacterial resistance exhibited significantly higher levels of per capita antibiotic use, ceteris paribus, the responsiveness of antibiotic use to changes in bacterial resistance was relatively low (0.09–0.18).ConclusionsThe study confirms that socioeconomic factors should be taken into account while explaining differences in outpatient antibiotic use across countries. The impact of supply-side factors and incentives attached to payment schemes for physicians need to be considered in government interventions to reduce inequalities and improve effectiveness in antibiotic utilisation.

Phenotypic and genotypic bacterial antimicrobial resistance in liquid pig manure is variously associated with contents of tetracyclines and sulfonamides

Antibiotic residues as well as antibiotic-resistant bacteria in environmental samples might pose a risk to human health. This study aimed to investigate the association between antibiotic residues and bacterial antimicrobial resistance in liquid pig manure used as fertilizer. Concentrations of tetracyclines (TETs) and sulfonamides (SULs) were determined by liquid chromatography-mass spectrometry in 305 pig manure samples; antibiotic contents were correlated to the phenotypic resistance of Escherichia coli (n = 613) and enterococci (n = 564) towards up to 24 antibiotics. In 121 samples, the concentration of the TET resistance genes tet(M), tet(O) and tet(B) was quantified by real-time-PCR. TETs were found in 54% of the samples. The median sum concentration of all investigated TETs in the positive samples was 0.73 mg kg(-1). SULs were found with a similar frequency (51%) and a median sum concentration of 0.15 mg kg(-1) in the positive samples. Associated with the detection of TETs and/or SULs, resistance rates were significantly elevated for several substances - some of them not used in farm animals, e.g. chloramphenicol and synercid. In addition, multiresistant isolates were found more often in samples containing antibiotics. Analysis of the resistance genes tet(M) and tet(O) already showed a significant increase in their concentrations - but not in tet(B) - in the lowest range of total TET concentration. Mean tet(M) concentrations increased by the factor of 4.5 in the TET concentration range of 0.1-1 mg kg(-1), compared to negative manure samples. Antibiotic contamination of manure seems to be associated with a variety of changes in bacterial resistance, calling for a prudent use of antibiotics in farm animals. This study provides an interdisciplinary approach to assess antimicrobial resistance by combining the microbiological analysis of bacterial resistance with high quality chemical analysis of antibiotic residues in a representative number of environmental samples.

Temporal changes in bacterial resistance in German intensive care units, 2001–2003: data from the SARI (surveillance of antimicrobial use and antimicrobial resistance in intensive care units) project

Conservative testing revealed a stable antibiotic resistance situation for Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Enterobacter cloacae in 32 German intensive care units (ICUs) actively participating in the SARI (surveillance of antimicrobial use and antimicrobial resistance in ICUs) project over a three-year period (2001--2003). No significant changes were shown for methicillin-resistant S. aureus (MRSA) (P=0.501; the MRSA rate increased in 18 ICUs and decreased in 14 ICUs). The only exception was an increase in ciprofloxacin-resistant E. coli.

Should we reevaluate antibiotic breakpoints?

The breakpoints used to interpret antimicrobial susceptibility tests should be carefully determined initially, using microbiological, pharmacokinetic, pharmacodynamic, and clinical data, and then reevaluated periodically as changes in bacterial resistance, susceptibility test methods, or antibiotic formulations occur. Throughout the world, different governmental agencies and professional organizations have responsibility for the initial establishment of antibiotic susceptibility breakpoints. In the United States, the National Committee for Clinical Laboratory Standards has a mechanism in place to establish breakpoints initially and to review and publish updates on an annual basis. There should be a continued effort to coordinate both susceptibility testing methods and breakpoint determinations in various parts of the world.

Bacterial resistance to penicillins and cephalosporins

The subject of bacterial resistance to penicillins and cephalosporins could be discussed from a number of points of view and clearly it is not possible in the time available to review adequately every aspect. Some selection is necessary and bearing in mind that the Symposium commemorates the thirtieth anniversary of the introduction of penicillin into medicine it seemed to me that it would be appropriate to consider primarily the changes which have taken place over this period in the incidence of resistance and the knowledge which has been gained concerning the nature of resistance to this family of antibiotics. Before we look at what the changes in resistance have been, however, it may be useful to consider what one means by the word resistant, and in fact one uses the word in two rather different ways. Used in one sense the term applies to those species of bacteria which are characteristically insensitive to penicillin, for example one may say that Pseudomonas aeruginosa is resistant to benzylpenicillin, because this is a characteristic of the species. On the other hand, the term resistant is also applied to particular strains of species of bacteria which are typically penicillin sensitive, or at least were typically sensitive at the time penicillin was first introduced into medicine, for example penicillin-resistant strains of staphylococci and penicillinresistant gonococci. As a result of these two uses of the word resistant some anomalies appear to arise. For example, strains of Escherichia coli inhibited by ampicillin at a concentration of 2 μg/ml would certainly be considered sensitive, whereas strains of gonococci inhibited by one-tenth of this concentration would be regarded as resistant and this is because typical sensitive strains are inhibited by even lower levels. Again, strains of P s . aeruginosa requiring for inhibition a concentration of gentamicin of 10 μg/ml would be said to be resistant, but strains inhibited by carbenicillin at a level as high as 50 μg/ml are considered sensitive. Here the reason is toxicity: a level of 10 μg/ml of gentamicin could not safely be maintained in the body, whereas a level of 50 μg/ml carbenicillin can. Clearly there are two criteria for judging organisms to be resistant, one is that the concentration of drug required to inhibit growth is a level which cannot readily be achieved at the site of infection and the other is simply that the minimum inhibitory concentration is significantly higher than that of the majority of strains of that particular species. Resistance to penicillins and cephalosporins, as with other antibiotics, may arise in bacteria in one of two ways. Resistance may occur as a result of chromosomal mutation or it may arise as a result of the transfer of genetic information from a resistant bacterial cell to a sensitive cell and this transfer may take place by transformation or by conjugation or by the phage mediated process of transduction. Resistant strains, once they arise, may be at a selectional advantage when the drug is used and as a result they may become more prevalent. The frequency at which antibiotic resistant strains arise, and the rate at which they subsequently increase in numbers, varies greatly with different antibiotics and different pathogens and some of the changes in bacterial resistance to penicillins which have occurred over the past 30 years are shown in diagrammatic form in figure 1.