Bacterial Resistance Monitoring Research Articles

Trends in antimicrobial resistance in Enterobacterales isolated from children: data from the China Antimicrobial Surveillance Network (CHINET) from 2015–2021

Antimicrobial resistance poses a significant threat to global public health, especially for Enterobacterales. In this study, we investigated the distribution and antimicrobial resistance of Enterobacterales in children in the China Antimicrobial Surveillance Network (CHINET) in 2015–2021. In total, 81,681 strains isolated from children were collected in this period, accounting for 50.1% of Gram-negative organisms. The most frequently isolated Enterobacterales were Escherichia coli, Klebsiella spp., Salmonella spp., and Enterobacter spp. The main sources of the isolates were urine and the respiratory tract, accounting for 29.3% and 27.7% of isolates, respectively. The proportions of E. coli, Klebsiella pneumoniae, and Proteus mirabilis expressing extended-spectrum β-lactamase were 48.8%–57.6%, 49.3%–66.7%, and 23.1%–33.8%, respectively. The prevalence of carbapenem-resistant Enterobacterales was 5.7%–9.5%, which showed a decreasing trend from 2015 to 2021. The detection rates of carbapenem-resistant Klebsiella spp., carbapenem-resistant Enterobacter spp., and carbapenem-resistant E. coli were 14.1%–22.6%, 7.1%–15.7% and 2.0%–3.4%, respectively. In Enterobacterales, the resistance rates to ciprofloxacin were higher than to levofloxacin. However, the Enterobacterales strains were highly susceptible to amikacin, polymyxin B, and tigecycline. The resistance rate of Salmonella spp. to ampicillin was > 70%, whereas their resistance rate to ceftriaxone was < 30%. These findings indicate that the resistant rates of some Enterobacterales isolates in children to common antimicrobial agents show decreasing trends. Continuous monitoring of bacterial resistance should be strengthened to prevent and control the spread of drug-resistant bacteria.

Emergence of aztreonam/avibactam and tigecycline-resistant Pseudomonas putida group Co-producing blaIMP-1, blaAFM-4 and blaOXA-1041 with a novel sequence type ST268 in Southwestern China

ObjectivesThe emergence of carbapenem-resistant Pseudomonas putida (CRPP) has raised public awareness. This study investigated two strains from the Pseudomonas putida group that were resistant to carbapenem, tigecycline, and aztreonam-avibactam (ATM−AVI), with a focus on their microbial and genomic characteristics. MethodsWe assessed the antibiotic resistance profile using broth dilution, disk diffusion, and E-test methods. Efflux pump phenotype testing and real-time quantitative PCR were employed to evaluate efflux pump activity in tigecycline resistance, while polymerase chain reaction was utilized to detect common carbapenem genes. Additionally, whole-genome sequencing was performed to analyze genomic characteristics. The transferability of blaIMP-1 and blaAFM-4 was assessed through a conjugation experiment. Furthermore, growth kinetics and biofilm formation were examined using growth curves and crystal violet staining. ResultsBoth strains demonstrated resistance to carbapenem, tigecycline, and ATM-AVI. Notably, NMP can restore sensitivity to tigecycline. Subsequent analysis revealed that they co-produced blaIMP-1, blaAFM-4, tmexCD-toprJ, and blaOXA-1041, belonging to a novel sequence type ST268. Although they were closely related on the phylogenetic tree, they exhibited different levels of virulence. Genetic environment analysis indicated variations compared to prior studies, particularly regarding the blaIMP-1 and blaAFM-4 genes, which showed limited horizontal transferability. Moreover, it was observed that temperature exerted a specific influence on their biological factors. ConclusionWe initially identified two P. putida ST268 strains co-producing blaIMP-1, blaAFM-4, blaOXA-1041, and tmexCD-toprJ. The resistance to tigecycline and ATM-AVI can be attributed to the presence of multiple drug resistance determinants. These findings underscore the significance of P. putida as a reservoir for novel antibiotic resistance genes. Therefore, it is imperative to develop alternative antibiotic therapies and establish effective monitoring of bacterial resistance.

An Approach to Track and Analyze the Trend of Antimicrobial Resistance Using Python: A Pilot Study for Anand, Gujarat, India-May 2022-August 2023.

The present work deals with the analysis and monitoring of bacterial resistance in using Python for the state of Gujarat, India, where occurrences of drug-resistant bacteria are prevalent. This will provide an insight into the portfolio of drug-resistant bacteria reported, which can be used to track resistance behavior and to suggest a treatment regime for the particular bacteria. The present analysis has been done using Python on Jupyter Notebook as the integrated development environment and its data analysis libraries such as Pandas, Seaborn, and Matplotlib. The data have been loaded from excel file using Pandas and cleaned to transform features into required format. Seaborn and Matplotlib have been used to create data visualizations and represent the data inexplicable manner using graphs, plots, and tables. This program can be used to study disaster epidemiology, tracking, analyzing, and surveillance of antimicrobial resistance with a proper system integration approach.

China antimicrobial resistance surveillance network for pets (CARPet), 2018 to 2021

China Antimicrobial Resistance Surveillance Network for Pets (CARPet) was established in 2021 to monitor the resistance profiles of clinical bacterial pathogens from companion animals. From 2018 to 2021, we recovered and tested 4,541 isolates from dogs and cats across 25 Chinese provinces, with Escherichia coli (18.5%) and Staphylococcus pseudintermedius (17.8%) being the most predominant bacterial species. The Enterobacterales were highly susceptible to tigecycline, meropenem, colistin, and amikacin (70.3%–100.0%), but showed moderate resistance to ampicillin, ceftriaxone, doxycycline, florfenicol, levofloxacin, enrofloxacin, and trimethoprim-sulfamethoxazole (29.3%–56.7%). About 66.3% of Acinetobacter spp. were resistant to florfenicol, with relatively low resistance to another 11 antibiotics (1.2%–23.3%). The Pseudomonas spp. showed high susceptibility to colistin (91.7%) and meropenem (88.3%). The coagulase-positive Staphylococcus spp. showed higher resistance rates to most antimicrobial agents than coagulase-negative Staphylococcus isolates. However, over 90.0% of Staphylococcus spp. were susceptible to linezolid, daptomycin and rifampin, and no vancomycin-resistant isolates were detected. E. faecium isolates demonstrated higher resistance rates to most antimicrobial agents than E. faecalis isolates. Streptococcus spp. isolates showed low resistance to most antimicrobial agents except for doxycycline (78.2%) and azithromycin (68.8%). Overall, the tested clinical isolates showed high rates of resistance to commonly used antimicrobial agents in companion animals. Therefore, it is crucial to strengthen the monitoring of bacterial resistance in pets. By timely and effectively collecting, analyzing, and reporting antimicrobial resistance dynamics in pets, the CARPet network will become a powerful platform to provide scientific guidance for both pet medical care and public health.

Character of wound microflora and resistance to antibiotics: monitoring results 2012–2020

The aim of the study was to improve the microbiological diagnosis of surgical infections, collect and analyze the data on the spectrum of surgical microflora and monitoring of antibiotic resistance in the period from 2012 to 2020.The research material was the separation of surgical wounds of patients, cultures of gram-negative and gram-positive bacteria isolated from the biological material of patients by the bacteriological method, the results of testing the sensitivity of bacterial cultures to antibiotics by diffusion into agar and using semi-automatic analyzers VITEK-2.A 9-year multicenter monitoring of the species composition of bacteria associated with wound infections revealed a high frequency of isolation of a number of conditionally pathogenic microorganisms – Escherichia spp., Klebsiella spp., Pseudomonas spp., Acinetobacter spp., Enterococcus spp., Streptococcus spp., Staphylococcus spp., Citrobacter spp., Proteus spp. In the period from 2012 to 2020, the amount of information entered into the computer database about these bacterial strains increased 1.4–2.0 times. Monitoring of bacterial resistance to antibiotics during this period showed a high level and dynamics to 3rd generation cephalosporins, carbapenems, and other classes. The lowest levels of resistance were found among the strains of Escherichia and the highest – Klebsiella, Pseudomonas and Acinetobacter. Staphylococci are characterized by high percentage of methicillin-resistant strains.Gram-negative (Escherichia, Klebsiella, Pseudomonas, Acinetobacter) and gram-positive (Enterococci, Streptococci, Staphylococci) are detected in the surgical patients with UTI with a high frequency. Surgical pathogens are characterized by a high level of resistance to 3rd generation cephalosporin, carbapenems, and other antibiotics. Long-term monitoring of bacterial resistance to antibiotics makes it possible to increase the effectiveness of laboratory diagnostics of surgical infections, to assess a resistance level of pathogens, an antibacterial therapy strategy and a medical aid quality.

The Role of CISH in the Prevention of Blood-Brain Barrier Disruption Induced By Meningitic Escherichia coli

Backgrounds: Despite the availability of antibiotics over the last several decades, an unmet requirement still exists for new practical therapeutic approaches to treat pediatric infections, especially in developing countries. Most of these deaths were caused by bacterial sepsis and meningitis (BSM), which is characterized by high mortality and adverse prognosis. Recently, CHINET (China bacterial resistance monitoring network) reported that "as the most common gram-negative bacterial pathogens causing BSM, Escherichia coli (E. coli) exhibits an uncontrollable, increasing multi-antibiotics resistance" (http://www.chinets.com). Antibiotics are effective in treating pediatric BSM, but antibiotic overuse increases the risk of drug resistance. In addition, excessive antibiotic treatments in BSM patients were related to several adverse outcomes, including necrotizing enterocolitis (NEC), late-onset sepsis (LOS), and even death. Hence, the crosstalk between host-pathogen interactions has become a new strategy and research point for developing antibiotic replacement therapy. Published studies suggest that the suppressor of cytokine signaling proteins (SOCS) are the main regulators in the innate immune reaction induced by a microbial pathogen, avoiding excessive inflammation. Recent studies have found that SOCS proteins can function as executors and contribute to the downregulation of proinflammatory factors associated with infection. As an important member of the SOCS family, the CISH protein defense mechanism of Pediatric E. Coli-induced BSM was unclear. This study explored the underlying defense mechanism of CISH during pediatric E. coli-induced BSM. Methods and materials: Sixteen mice were randomly divided into two groups (control group, E. coli E44 group). Mice were given sterile normal saline and E. coli E44 (1×107CFU/mouse) by intraperitoneal administration, respectively. After infection for 8 h, mice in different groups were sacrificed to collect brain tissues and fixed in 10% formalin buffer solution for 24h. The sample were pretreated (dehydration, embedding, sectioning, hyalinization, H&E staining and sealing) and morphological observations. Human brain microvascular endothelial cells (HBMECs) in 6-well plates (1×105 cells/well) were cotransfected with GV492-CISH plasmid and siRNA using Lipofectamine 3000 reagent. The vector GV492-CISH (MW: 12.7 kb) was identified by restriction enzyme digestion and nucleotide sequencing. Then, the cells were incubated for 2-3 days to constructed the CISH overexpression HBMECs. HBMECs were inoculated in 96-well plates (excluding the edge effect) and divided into a control group, E. coli E44 infection group and E. coli E44+CISH siRNA pretreatment group. After E. coli. E44 infection for 2 h, the expression of Occludin was detected by Western Boltting. SPSS 20.0 software was used for statistical analysis. P <0.05 were considered statistically significant. Results: H&E staining showed that E. coli E44 could induce impairments in endothelial cells and cause brain microvascular damage. Histological damage was characterized by microvascular collapse, destruction of the bases, and RBC cells that were irregularly positioned into the tissue space. Few well-structured blood capillaries could be observed under a typical view. Expression of Occludin declined significantly in the E. coli E44 infection group compared with the uninfected group(P<0.01). In addition, compared with the untreated group, designed siRNA showed an acceptable inhibition effect of CISH with statistical significance (P<0.05). The expression of Oc-cludin in HBMECs treated with siRNA decreased significantly compared with that in HBMECs not treated with siRNA after infection (P<0.01). These results suggested that CISH defense mechanism during pediatric E. coli-induced BSM, CISH knockdown aggravated E. coli-induced blood brain barrier injury in BSM. Conclusions: In conclusion, the completion of this study reveals the protective mechanism of CISH in meningitic Escherichia coli-induced HBMECs injuries and BBB disruptions. CISH deficiency reduces the expression of Occludin, which aggravates the damage of BBB induced by Escherichia coli infected.(Acknowledgements: X.G. and J.Z. contributed equally to this work; Corresponding author: Hong Cao, gzhcao@smu.edu.cn; National Natural Science Foundation of China, No. 81871198 to H.C.)Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Genetic characterization of Carbapenem-Resistant\xa0Escherichia coli\xa0from China, 2015\u20132017

BackgroundThe molecular characteristics of carbapenem-resistant Escherichia coli (CREco) remain unclear.MethodsWe conducted a multi-center bacterial resistance monitoring project from 2015 to 2017.The minimum inhibitory concentrations ofCREco were determined bybroth microdilution method. The genome sequencing of CREcoisolates was performed, and single-nucleotide polymorphism (SNP) was analyzed.ResultsA total of 144CREcoisolatescollected from 10 cities in China were involved in this study. ST167 (n = 43) is the most popular type, followed by ST410(n = 14), ST131(n = 9). There were 102 (70.83%) CREco isolates that produced various NDMs, including NDM-1 (n = 16), NDM-4(n = 1), NDM-5(n = 79), NDM-6(n = 2) and NDM-9(n = 4). In addition, 15 isolates produced KPC-2, three isolates wereIMP-4 positive, and three isolates produced OXA-48. Genetic relatedness and phylogenetic analysis showed that isolates with the same ST had a high degree of homology. Some STs (including ST167, ST410, ST131, ST46, ST405 and ST617) exhibited a trend of outbreak.ConclusionsThe majority of CREco belonged to ST167, followed by ST410 and ST131, and most of them carried various NDM-coding genes. The spread of high-risk clones of CREco has occurred in different regions of China.

Consensus Recommendations Based on Evidence for Abdominal Sepsis in the Pediatric and Adult Population of Colombia

Intra-abdominal infections are frequent at all levels of health care, therefore, it is necessary to maintain a high level of clinical suspicion, performing the fastest and most cost-effective measures to confirm the diagnosis and offer a precise and targeted multidisciplinary therapy, this being the only way to have an impact on the morbidity of this infection, reducing mortality and minimizing the complications and costs of health care. Intra-abdominal infections are linked to the appearance and selection of resistant mutants in both bacteria and fungi, becoming currently a major public health problem. Increasing bacterial resistance when associated with a greater possibility of difficulties in antimicrobial treatment increases mortality. This evidence-based consensus brings together the recommendations for the diagnosis and treatment of intra-abdominal infections in the pediatric and adult population. With strict monitoring of bacterial resistance and stimulating the control of the risk factors that have the greatest impact on the appearance of this phenomenon, this consensus is intended to be a practical guide that is easy to implement, and with periodic updates it will favor and facilitate multidisciplinary and the adequacy of the therapeutic management of intra-abdominal infections.

Emergence of Transferable mcr-9 Gene-Carrying Colistin-Resistant Salmonella enterica Dessau ST14 Isolated from Retail Chicken Meat in Korea.

Colistin is an important antibiotic currently used to manage infections caused by multidrug-resistant pathogens in both humans and livestock animals. A new mobile colistin-resistance (mcr-9) gene was recently discovered; this discovery highlighted the need for rigorous monitoring of bacterial resistance against colistin. Salmonella is one of the major pathogens responsible for foodborne illnesses; however, there is minimal information regarding the presence of mcr genes in foodborne Salmonella strains. The aim of this study was to investigate the presence of mcr genes among 178 Salmonella strains isolated from chicken meat in Korea. Antimicrobial susceptibility was measured using the broth microdilution method. Bioinformatics characterization of colistin-resistant strains and genetic environment of the mcr-9 gene were analyzed using next-generation sequencing. Transferability of the mcr-9 carrying colistin-resistant Salmonella strain was tested using broth-mating conjugation. Thirteen of the 178 Salmonella isolates showed colistin resistance, but only one strain, Salmonella Dessau ST14 (KUFSE-SAL043) from a traditional chicken market in Korea, carried an mcr family gene, mcr-9. This strain also carried other acquired antimicrobial resistance genes such as blaTEM-1B, qnrS1, and aac(6')-Iaa. Only the IncX1 plasmid replicon type was detected in this strain. In the strain KUFSE-SAL043, the mcr-9 gene was located between two insertion sequences, IS903B and IS26, followed by the downstream regulatory genes qseB-like and qseC-like, which were located between IS1R and ΔIS1R. Conjugation tests revealed that the mcr-9 gene was successfully transferred to Escherichia coli J53 at a mean frequency of 2.03 × 10-7. This is the first report of a transferable mcr-9 gene in Salmonella isolated from chicken meat in Korea, highlighting the possibility of transfer of colistin resistance. Therefore, the wide use of colistin should be reconsidered, and a One Health perspective should be adopted to monitor the antimicrobial resistance of Enterobacteriaceae strains in humans, livestock, and the environment.

Analysis of drug resistance and risk factors of community-acquired urinary tract infection caused by extended-spectrum β-lactamase-producing Escherichia coli in children

Objective To investigate the drug resistance and risk factors of community-acquired urinary tract infection(UTI) caused by extended-spectrum β-lactamase(ESBLs)-producing Escherichia coli in children. Methods The clinical data of 125 children with community-acquired urinary tract infection caused by Escherichia coli were analyzed, who were hospitalized at Department of Pediatric Nephrology of Tianjin Children′s Hospital from June 2017 to June 2018.The ESBLs-producing group and the non ESBLs-producing group were named depending on the production of the ESBLs.WHONET 5.6 bacterial resistance monitoring software was used to calculate the drug resistance rate of bacteria.The drug resistance rate and clinical data were analyzed by adopting χ2 test and Fisher′s exact probability method, then, factors with statistical significance identified by single factor analysis were further analyzed by multivariate Logistic regression analysis. Results Among 125 strains of Escherichia coli, 68 strains(54.4%) were ESBLs-producing Escherichia coli and 57 strains(45.6%) were non ESBLs-producing.The drug resistance rates of ESBLs-producing Escherichia coli to penicillins, cephalosporins, quinolones and monocyclic beta-lactams were higher than those of non ESBLs-producing strains, and the drug resistance rates to Ampicillin, Piperacillin, Cefazolin, Cefuroxime, Ceftriaxone and Cefotaxime were nearly 100%.The resistance rates of ESBLs-producing strains to Imipenem, Meropenem, Amikacin, Furantoin, Cefotetan and Piperacillin/Tazobactam were lower (< 5%). Univariate analysis showed that there were significant differences in recurrent UTI (χ2=12.043, P<0.01) and use of third-generation cephalosporins in the past 3 months(χ2=28.545, P<0.01) between ESBLs-producing group and non ESBLs-producing group.Multivariate Logistic regression analysis showed that use of third-generation cephalosporins in the past 3 months was an independent risk factor of community-acquired UTI caused by ESBLs-producing Escherichia coli(OR=11.285, 95%CI: 3.140-39.134, Wald=13.972, P<0.01). Conclusions The isolation rate of ESBLs-producing Escherichia coli in children with community-acquired UTI is high, and the drug resistance rate is high, so children who used third-generation cephalosporins in the past 3 months were more likely to develop community-acquired UTI caused by ESBLs-producing Escherichia coli. Key words: Urinary tract infection; Escherichia coli; Extended-spectrum β-lactamase; Child

Impact of oral and intramuscular administration amoxicillin on the selection of amoxicillin-resistant &lt;i&gt;Enterobacteriaceae&lt;/i&gt; in the digestive flora of piglets

Objective: The aim of this study was to evaluate the level of selection of amoxicillin-resistant Enterobacteriaceae in the digestive microbiota of piglets during oral and intramuscular administration of amoxicillin. Methodology and Results: Enumeration of Enterobacteriaceae was carried out on MacConkey agar with and without amoxicillin. E. coli isolates were identified and subjected to antimicrobial susceptibility test. The percentages of amoxicillin-resistant Enterobacteriaceae before treatment were between 10-13% for the three groups of piglets. After starting treatment of amoxicillin, from day 1 to day 4, the percentages of resistant Enterobacteriaceae were between 54 to 81% for the intramuscular treated groups and 58 to 87% for those treated orally. In the control group, percentage was 11%. During days of treatments, the percentage of amoxicillin-resistant E. coli strains to the associated antibiotics evolved during the treatments. In the control piglets, the percentages of E. coli resistant antibiotics did not increase. Conclusion and application of findings: Administration of oral amoxicillin resulted in a greater selection of resistant enterobacteria in the digestive microbiota of piglets than those induced by the intramuscular route. Escherichia coli , an important strain in animal and human pathology, was the target of detection in this selection of these resistant enterobacteria. They constitute a public health risk due to the transfer of resistance genes from pathogenic bacteria of porcine origin to the human digestive flora via the food chain. The results obtained from this study are part of a bacterial resistance monitoring policy that will prevent pig farmers from Cote d’Ivoire, the majority user of these antibiotics. Keywords: Piglets, Enterobacteriaceae , Amoxicillin, Resistance, Digestive microbiota

Situation of drug-resistant bacteria and infection control strategy

To understand the situation of drug-resistant of China based on the bacterial resistance monitoring data in 2010.Using the international guidelines for reference to propose the prevention and infection control strategy.The monitoring data shows that bacterial resistance is still growing in China which brings enormous difficulties on clinical treatment and poses a serious threat to the safety of patients.By strengthening the surveillance of bacterial resistance, reducing the use of antibiotics, strengthening the etiological examination, improving the use of antibiotics, strictly carrying out hand hygiene, disinfection and isolation system will be the key points of the prevention and infection control for drug-resistant bacteria.（Chin J Lab Med,2012,35:682-684） Key words: Drug resistance，bacterial; Infection control

Off‐label drug use evaluation in paediatrics—applied to ciprofloxacin when used as treatment of cholangitis

To evaluate drug and indication specific off-label use in paediatrics, applied to ciprofloxacin (CPFX) in cholangitis. We collected four different sets of data for an off-label drug use evaluation. (1) Literature review from medical journals, (2) the use and safety profile from the whole Swedish paediatric population by extracting data from national registers, (3) locally performed retrospective drug chart reviews, and (4) interviews regarding paediatric patients with CPFX treated cholangitis. The literature reviews show a lack of information for paediatric use of CPFX in cholangitis. The prescribing of CPFX to Swedish children has grown over the last decade and generated a small number of reports for adverse drug reactions. In our local biliary atresia population 32 patients had suffered from at least one episode of cholangitis and 13 patients had been prescribed CPFX. The dosing strategy had an empirical prescribing approach, since monitoring of bacterial resistance and efficacy is difficult in the biliary ducts. No clear relationship was seen between dosing and age/weight. Reports of suspected side effects could not be found in the retrospective chart reviews. The interviews show that the existing dosage forms are well accepted. This drug use evaluation creates awareness of the off-label situation. The international and national data are sparse for the paediatric use of CPFX in cholangitis. Locally we have highlighted a heterogeneous dosing strategy of CPFX, drug/drug interactions, and the need to monitor and report the risk of short- and long-term adverse drug reactions.

How to fight antimicrobial resistance

Antimicrobial misuse results in the development of resistance and superbugs. Over recent decades, resistance has been increasing despite continuing efforts to control it, resulting in increased mortality and cost. Many authorities have proposed local, regional and national guidelines to fight against this phenomenon, and the usefulness of these programmes has been evaluated. Multifaceted intervention seems to be the most efficient method to control antimicrobial resistance. Monitoring of bacterial resistance and antibiotic use is essential, and the methodology has now been homogenized. The implementation of guidelines and infection control measures does not control antimicrobial resistance and needs to be reinforced by associated measures. Educational programmes and rotation policies have not been evaluated sufficiently in the literature. Combination antimicrobial therapy is inefficient in controlling antimicrobial resistance.

Escherichia coli des infections urinaires et pyélonéphrites aiguës en pédiatrie : 1 % des souches sont résistantes à certaines céphalosporines de 3 e génération

E. coli remains the most often isolated pathogen in community urinary tract infections in children. We reported a retrospective study of antibiotic susceptibility of 506 E. coli strains isolated from urine. We found that 53% of the strains were resistant to amoxicilline and 22% to cotrimoxazole. The frequency of resistance to amoxicillin–clavulanic acid was of 7%, 40% of the strains were just intermediary and 53% were sensitive. Only five strains (1%) were resistant to ceftazidime: two mechanisms of resistance, hyperproduction of TEM betalactamase (3 cases) and cephalosporinase (2 cases), were suggested. This study illustrates the necessity of constant monitoring of bacterial resistance to adapt antibiotherapeutic guidelines to local evolution.

Antibiograms: New NCCLS Guidelines, Development, and Clinical Application

Antibiograms are an important resource for health care providers. All clinicians involved in antibiotic selection and monitoring should become familiar with the NCCLS M39-A document “Analysis and Presentation of Cumulative Antimicrobial Susceptibility Test Data: Approved Guideline.” Providers who interpret and apply antibiogram data in clinical practice should know about susceptibility testing methods, the susceptibility breakpoint determination process, and problems associated with antibiogram data analysis. The M39-A guidelines contain more than 40 recommendations, including the following: antibiogram data should be analyzed at least annually, an attempt should be made to remove duplicate isolates, and only organisms with 10 isolates or more should be presented. Accurate antibiograms facilitate improved empiric antibiotic selection and more precise monitoring of bacterial resistance in the hospital. This article reviews common antimicrobial susceptibility testing methods and relevant issues, highlights the major NCCLS M39-A recommendations, discusses the antibiogram preparation process and challenges in data interpretation, and provides a general overview of how antibiogram data may be applied to clinical practice.

A comparison of the performance of commercially available chromogenic agars for the isolation and presumptive identification of organisms from urine

Aims: To compare four media—UTI medium, BBL CHROMagar, CPS ID2, and Harlequin CLED—using a collection of fully characterised organisms and subsequent “field trial”. Methods: Seven hundred and eighty seven fully...

Détection et surveillance épidémiologique des résistances bactériennes aux antibiotiques en milieu communautaire

The monitoring of bacterial resistance to antibiotics in non-hospitalized patients is essential. More than 80% of antibiotics are prescribed in the community and many patients can carry multiresistant bacteria after hospitalization. In addition to its role in the diagnosis and assistance in the treatment of the community acquired infections, the biologist can integrate a surveillance network of bacterial resistance to antibiotics. This monitoring must consider historical and medical informations concerning the patients. Previous antibiotic treatment, or hospitalization are factors of major concern in the variation of resistance to antibiotics and species of the bacteria isolated from urinary tract infections in the community. Previous hospitalization is frequently found among patients carrying methicillin resistant Staphylococcus aureus. Recent antibiotic treatment is related to an important prevalence of Streptococcus pneumoniae presenting a decreased susceptibility to penicillin G. The notion of re-infection in often found when Haemophilus influenzae producing β-lactamase are isolated. The monitoring of the evolution of resistance to fluoroquinolones in Neisseria gonorrhoeae, and Salmonella Hadar and the survey of resistance to macrolides in β-haemolytic streptococci are also important objectives.

Short-term impact of the European Consensus Conference on the use of selective decontamination of the digestive tract with antibiotics in ICU patients.

Because it remained controversial, the use of selective digestive decontamination (SDD) in patients in the intensive care unit (ICU) was chosen as the topic of the first European Consensus Conference in Intensive Care Medicine (ECCICM) in December, 1991. The Consensus Bureau decided to assess the impact of this conference 2 years afterwards. For this purpose, a questionnaire was sent to the members of the European Society of Intensive Care Medicine, the Societé de Réanimation de Langue Française and the Societé Française d'Anesthesie et Réanimation before the conference. The recommendations following the conference discouraged the systematic use of SDD in ventilated patients and urged the monitoring of bacterial resistance and adapting antibiotics to epidemiology of the units. Two years after the conference, the same questionnaire was sent to those physicians who had responded to the first one. Eighteen percent used SDD for all ventilated patients and 17% remain users after 2 years. Among the occasional (32%) or continual (17%) users of SDD, the regimens used were mostly intravenous cefotaxime (60% of systemic antibiotics) and a topical combination of polymixin E, tobramycin, and amphotericin B (62% of overall topical combinations). The antibiotics used were unchanged after 2 years in almost all cases. In conclusion, the short-term impact of the Consensus Conference on SDD in ICU patients has been poor. This may be related to the continuing insufficiency of strong, definite data regarding the impact of this technique upon mortality and the theoretical risk of resistance to antibiotics, thus allowing physicians to stick to their policies until there is new evidence.

Bacterial resistance monitoring in animals: the French national experiences of surveillance schemes

In France, bacterial resistance monitoring in animals is based on a national network of local veterinary laboratories organised by CNEVA following two methodologies. As part of the epidemiological surveillance of Salmonella, LCHA in Paris has been receiving since 1969 most of the strains isolated from animals (sick and healthy carriers) but also from food, feed and environment. For many years sensitivity tests have been carried out on strains collected: animal ones, mainly from cattle and poultry, show multiple antibiotic resistance more frequently than those of food or environment. Taking into account of the importance of antibiotic resistance in E. coli and Salmonella isolated from sick calves, LPB in Lyon has set up since 1982 a national system for collecting and analysing antimicrobial sensitivity patterns of main bovine pathogens determined routinely by local veterinary laboratories. In order to ensure comparability and coherency of data from different laboratories it was necessary to introduce standard techniques and reference reagents. The major bacterial species being tested concern enteric, respiratory and mammary flora. This network is useful to detect new resistances. The resistant strains collected are useful to carry out studies on the mechanism of resistance and the efficacy of new molecules. Results constitute the basis of a real predictive epidemiology necessary to lay down a policy for rational use of antimicrobials in animal breeding and veterinary medicine.