High Levels Of Antimicrobial Resistance Research Articles

EMPIRICAL VERSUS SUSCEPTIBILITY-BASED ERADICATION THERAPY FOR HELICOBACTER PYLORI INFECTION IN EGYPT

Background: The eradication rate of Helicobacter pylori has declined, mainly due to antimicrobial resistance. Objectives: To test the effectiveness of susceptibility guided therapy vs. the empirical triple therapy for first: line H pylori treatment in a region with high antimicrobial resistance. Patients and methods: The study was performed on 82 dyspeptic H. pylori patients arranged for esophagogastroduodenoscopy at Al-Hussein University Hospital between March 2019 to march 2020. Patients were randomly divided into two groups: group A consisted of 52 patients underwent endoscopy and gastric biopsies for culture and sensitivity and treated according to sensitivity results and group B consisted of 30 patients treated by empiric triple therapy. Eradication rates and drug compliance owing to adverse effects were compared between the two groups. Results: In total, 82 patients were enrolled (52 in culture and sensitivity-based therapy group and 30 in empirical therapy group) and 50 patients (60.1%) completed the protocols. The overall resistance rates to clarithromycin, amoxicillin, metronidazole, levofloxacin, tetracycline, nitrofurantoin and rifampicin were 32.1%, 32.1%, 78.6%, 7.1%, 17.9%, 17.9% and 21.4% respectively. Empirical triple and antimicrobial susceptibility-guided eradication rates were, respectively, 53.3% and 85.7% by intention-to-treat and 64% and 96% by per-protocol analysis. Adverse events were reported in 16.6% of patients on empirical triple therapy and 21.4% of those on susceptibility-guided therapy. Conclusions: Culture-based eradication strategy demonstrated superior eradication efficacy than empirical therapy as a first-line therapy in a region with high levels of antimicrobial resistance.

Implementation and evaluation of different eradication strategies for Brachyspira hyodysenteriae

BackgroundBrachyspira infections are causing major losses to the pig industry and lead to high antimicrobial use. Treatment of Brachyspira (B.) hyodysenteriae infections may be problematic due to the high level of antimicrobial resistance. The present study implemented and evaluated farm-specific eradication programmes for B. hyodysenteriae in 10 different infected pig farms in Belgium.ResultsTen pig farms clinically infected with B. hyodysenteriae volunteered to implement a farm-specific eradication programme. The programme depended on the farm and management characteristics, antimicrobial susceptibility of the B. hyodysenteriae strain and the motivation of the farmer. Two farms practiced total depopulation, six farms partial depopulation and two farms antimicrobial medication without depopulation. In addition, all farms implemented biosecurity measures, and faeces samples were tested for the presence of B. hyodysenteriae at 6, 9 and 12 months after the start of the program. Single Brachyspira isolates from before and after the programme were typed using multilocus sequence typing (MLST).Eradication was successful in four farms. Two of them (farrow-to-finish and finishing herd) had applied total depopulation and respected a vacancy period of at least 3 weeks. A third farm (gilt farm) practised partial depopulation, the rooms remained empty for 28 days and changed the source of breeding gilts. The fourth farm practised partial depopulation, the stables remained empty for 3 weeks, and used antimicrobial medication. The eradication programme was not successful in six farms. Two of the latter farms only used medication without partial depopulation. Four farms practiced partial depopulation, one of them combined it with antimicrobial medication. The cleaning and disinfection procedures, rodent control, stand-empty period and/or other biosecurity measures in the six farms were not always implemented properly. In two of three farms, isolates belonging to the same MLST type were found before and after eradication.ConclusionsTotal depopulation or partial depopulation combined with implementing strict biosecurity measures allowed eradication of B. hyodysenteriae from clinically infected pig farms. Programmes based on antimicrobials without depopulation or partial depopulation without strictly adhering to all suggested biosecurity measures were not successful. Stockmanship and motivation of the farmer to permanently maintain high biosecurity standards are essential for success.

Antimicrobial Resistance of Campylobacter spp. Causing Human Infection in Australia: An International Comparison.

The study investigates the prevalence of antimicrobial resistance in Campylobacter jejuni and Campylobacter coli in gastroenteritis patients in the eight most populous regions in Australia and compares the prevalence of antimicrobial resistance in Europe and North America. A total of 164 Campylobacter isolates were collected from patients with campylobacteriosis and tested for susceptibility to six antimicrobials using ETEST® strips and compared with reports from Europe and the United States. Genomes were sequenced on Illumina NextSeq to identify genetic determinants of resistance. Phenotypically, 1.8%, 14.0%, 14.6%, and 20.1% of isolates were resistant to erythromycin (ERY), ampicillin, tetracycline (TET), and ciprofloxacin (CIP), respectively. Comparing published phenotypic results of antimicrobial resistance in several European countries and the United States with these Australian isolates reveals that rates observed in Australia are among the lowest observed for ERY, CIP, and TET for both C. coli and C. jejuni. For each antimicrobial tested, concordance between resistance phenotype and genotype ranged from 66.6% to 100.0%. This study highlights that, among industrialized countries, Portugal and Spain have very high levels of antimicrobial resistance in C. jejuni and C. coli, especially when compared with the United Kingdom, United States, and Australia.

De-escalation of antimicrobial therapy in ICU settings with high prevalence of multidrug-resistant bacteria: a multicentre prospective observational cohort study in patients with sepsis or septic shock.

De-escalation of empirical antimicrobial therapy, a key component of antibiotic stewardship, is considered difficult in ICUs with high rates of antimicrobial resistance. To assess the feasibility and the impact of antimicrobial de-escalation in ICUs with high rates of antimicrobial resistance. Multicentre, prospective, observational study in septic patients with documented infections. Patients in whom de-escalation was applied were compared with patients without de-escalation by the use of a propensity score matching by SOFA score on the day of de-escalation initiation. A total of 262 patients (mean age 62.2 ± 15.1 years) were included. Antibiotic-resistant pathogens comprised 62.9%, classified as MDR (12.5%), extensively drug-resistant (49%) and pandrug-resistant (1.2%). In 97 (37%) patients de-escalation was judged not feasible in view of the antibiotic susceptibility results. Of the remaining 165 patients, judged as patients with de-escalation possibility, de-escalation was applied in 60 (22.9%). These were matched to an equal number of patients without de-escalation. In this subset of 120 patients, de-escalation compared with no de-escalation was associated with lower all-cause 28 day mortality (13.3% versus 36.7%, OR 0.27, 95% CI 0.11-0.66, P = 0.006); ICU and hospital mortality were also lower. De-escalation was associated with a subsequent collateral decrease in the SOFA score. Cox multivariate regression analysis revealed de-escalation as a significant factor for 28 day survival (HR 0.31, 95% CI 0.14-0.70, P = 0.005). In ICUs with high levels of antimicrobial resistance, feasibility of antimicrobial de-escalation was limited because of the multi-resistant pathogens isolated. However, when de-escalation was feasible and applied, it was associated with lower mortality.

Spatial Exposure of Agricultural Antimicrobial Resistance in Relation to Free-Ranging Domestic Chicken Movement Patterns among Agricultural Communities in Ecuador.

The use of antimicrobial growth promoters in chicken farming has been commonly associated with high levels of antimicrobial resistance (AMR) in humans. Most of this work, however, has been focused on intensive large-scale operations. Intensive small-scale farming that regularly uses antibiotics is increasing worldwide and has different exposure pathways compared with large-scale farming, most notably the spatial connection between chickens and households. In these communities, free-ranging backyard chickens (not fed antibiotics) can roam freely, whereas broiler chickens (fed antibiotics) are reared in the same husbandry environment but confined to coops. We conducted an observational field study to better understand the spatial distribution of AMR in communities that conduct small-scale farming in northwestern Ecuador. We analyzed phenotypic resistance of Escherichia coli sampled from humans and backyard chickens to 12 antibiotics in relation to the distance to the nearest small-scale farming operation within their community. We did not find a statistically significant relationship between the distance of a household to small-scale farming and antibiotic-resistant E. coli isolated from chicken or human samples. To help explain this result, we monitored the movement of backyard chickens and found they were on average 17 m (min-max: 0-59 m) from their household at any given time. These backyard chickens on average ranged further than the average distance from any study household to its closest neighbor. This level of connectivity provides a viable mechanism for the spread of antimicrobial-resistant bacteria and genes throughout the community.

CTX-M-9 group ESBL-producing Raoultella planticola nosocomial infection: first report from sub-Saharan Africa

BackgroundRaoultella are Gram-negative rod-shaped aerobic bacteria which grow in water and soil. They mostly cause nosocomial infections associated with surgical procedures. This case study is the first report of a Raoultella infection in Africa.Case presentationWe report a case of a surgical site infection (SSI) caused by Raoultella planticola which developed after caesarean section (CS) and surgery for secondary small bowel obstruction. The patient became febrile with neutrophilia (19,157/µL) 4 days after laparotomy and started to develop clinical signs of a SSI on the 8th day after laparotomy. The patient continued to be febrile and became critically ill despite empirical treatment with ceftriaxone and vancomycin. Raoultella species with extended antimicrobial resistance (AMR) carrying the CTX-M-9 β-lactamase was isolated from the wound discharge. Considering the antimicrobial susceptibility test, ceftriaxone was replaced by ceftazidime. The patient recovered and could be discharged on day 29 after CS.ConclusionsRaoultella planticola was isolated from an infected surgical site after repeated abdominal surgery. Due to the infection the patient’s stay in the hospital was prolonged for a total of 4 weeks. It is noted that patients undergoing surgical and prolonged inpatient treatment are at risk for infections caused by Raoultella. The development of a SSI caused by Raoultella planticola with extended AMR has to be assumed to be a consequence of ineffective antibiotic utilization. The presented case advices that rare bacteria as Raoultella should be considered as potential cause of nosocomial SSI with challenging treatment due to high levels of AMR.

An investigation into extended spectrum beta-lactamase colonisation in travellers to Laos

Increased frequency of global travel has facilitated the spread of antimicrobial resistant organisms like extended spectrum β-lactamase (ESBL)- producing organisms and carbapenamase-producing Enterobacteriaceae through increased exposure and transient or persistent colonisation. This study investigates the impact of travel to Laos and of faecal colonisation with ESBLs aiming to help understand the diversity of organisms and also persistency of antimicrobial resistance (AMR) during the study and on return. Daily faecal samples were collected from 23 doctors visiting Laos over a 21-day period which allowed detection of both constant colonisation and changes to the bowel colonisation over time. Bioinformatic techniques were used to identify ESBL-producing isolates obtained from participants and their contacts. Isolates were sequenced, assembled and annotated. SNP analysis was performed and phylogenetic trees constructed using the core SNP alignment. Escherichia coli was the most prevalent species with a highly diverse array of sequence types. Citrobacter and Klebsiella were the most abundant non-E. coli species. This study confirmed that Laos is an area with high levels of AMR with 28% isolates found to have mobile colistin resistance. There was also a highly diverse and extensive spread of unexpected blaCTX-M genes. Prolonged persistence of resistance genes in the three most prevalent study species found after travellers returned is another serious cause for concern emphasising the extended risk of spread of AMR from high risk to low risk countries. Future work will allow exploration of possible AMR transmission and horizontal transfer of resistance between isolates.

Prevalence and antibiogram of coliform bacteria, and occurrence of fungi in subclinical mastitis in small ruminants in Plateau State, Nigeria

This study was conducted to determine the prevalence of coliform bacteria and fungi in ovine and caprine raw milk in Plateau State of Nigeria. In a cross sectional study, a total of 412 milk samples were collected aseptically and 206 questionnaires form where data such as breed, age, parity, lactation stage, floor type, and husbandry system were analyzed. Ewes and does without clinical mastitis were subjected to California Mastitis Test (CMT) to determine the presence of subclinical mastitis. Bacteriological assays and antibiotic susceptibility tests were performed according to standard guidelines. Fungal assays and identification were done according to standard protocol. The overall prevalence of subclinical mastitis for ewes and does were 28.2 and 35.8% respectively. Out of the risk factors examined, age and floor type showed statistically significant relationship with mastitis. Coliforms isolated from milk samples included Escherichia coli, Klebsiella pneumoniae, Citrobacter freundii, Enterobacter aerogenes, and Serratia marcescens. The highest coliform isolated among the ewes with 38% prevalence was E. coli and the least was S. marcescens with 2.5%. Among the does, E coli had the highest prevalence as well with 43.1% and E. aerogenes the least with 1.5%. Aspergillus species had 49 isolates out of the 94 fungal isolates (52.1%) of mycotic agents of mastitis in small ruminants. Most antibiotics used in this study showed extremely high level of antimicrobial resistance especially for Amoxicillin-clavulanic acid 45/79 (57.0%) and 53/65 (81.5%) in coliforms isolated from ewes and does respectively. The principle of one health approach which targets the environment, animals and humans should be considered important. Sensitization of pastoralists on good hygienic measures, and treatment of animals by qualified and registered veterinary personnel should be intensified.

Antimicrobial resistance in bacteria isolated from pigs with respiratory clinical signs in Brazil

Antimicrobial resistance is a current and important issue to public health, and it is usually associated with the indiscriminate use of antimicrobials in animal production. This study aimed to evaluate the antimicrobial susceptibility profile in bacterial isolates from pigs with clinical respiratory signs in Brazil. One hundred sixty bacterial strains isolated from pigs from 51 pig farms in Brazil were studied. In vitro disk-diffusion method was employed using 14 antimicrobial agents: amoxicillin, penicillin, ceftiofur, ciprofloxacin, enrofloxacin, chlortetracycline, doxycycline, oxytetracycline, tetracycline, erythromycin, tilmicosin, florfenicol, lincomycin, and sulfadiazine/trimethoprim. The majority of isolates were resistant to at least one antimicrobial agent (98.75%; 158/160), while 31.25% (50/160) of the strains were multidrug resistant. Streptococcus suis and Bordetella bronchiseptica were the pathogens that showed higher resistance levels. Haemophilus parasuis showed high resistance levels to sulfadiazine/trimethoprim (9/18=50%). We observed that isolates from the midwestern and southern regions exhibited four times greater chance of being multidrug resistant than the isolates from the southeastern region studied. Overall, the results of the present study showed a great level of resistance to lincomycin, erythromycin, sulfadiazine/trimethoprim, and tetracycline among bacterial respiratory pathogens isolated from pigs in Brazil. The high levels of antimicrobial resistance in swine respiratory bacterial pathogens highlight the need for the proper use of antimicrobials in Brazilian pig farms.

Association of Neisseria gonorrhoeae Plasmids With Distinct Lineages and The Economic Status of Their Country of Origin.

Plasmids are vehicles for horizontal gene transfer between bacteria, and in Neisseria gonorrhoeae plasmids can mediate high-level antimicrobial resistance (AMR). Using genomic and phylogenetic analyses, we show that plasmids are widespread in a collection of 3724 gonococcal isolates from 56 countries, and characterized the conjugative, β-lactamase and cryptic plasmids. We found that variants of the conjugative plasmid (which can mediate tetracycline resistance) and the β-lactamase plasmid expressing TEM-135 are associated with distinct gonococcal lineages. Furthermore, AMR plasmids are significantly more prevalent in gonococci from less wealthy countries, highlighting the need for further studies. More than 94% of gonococci possess the cryptic plasmid, with its absence correlated with the presence of a novel chromosomal type IV secretion system. Our results reveal the extent of plasmid-mediated AMR in the gonococcus, particularly in less wealthy countries, where diagnostic and therapeutic options can be limited, and highlight the risk of their global spread.

Prevalence, associated risk factors, and antimicrobial resistance profiles of non-typhoidal Salmonella in large scale swine production in Córdoba, Argentina

Non-typhoidal Salmonella is considered a major public health concern. The growing relevance of pigs as reservoir of Salmonella spp. has prompted several countries to set up surveillance and control programs to fight Salmonella infection in swine and reduce public health risk. In the last decade, pork production in Córdoba increased significantly to become one of the most important pig production provinces in Argentina. The aim of this study was to estimate Salmonella spp. prevalence and associated risk factors in large scale-farms in this province. Mesenteric lymph nodes (MLN) of 580 pigs from 20 finishing large-scale farms were collected between 2014 and 2015 to estimate Salmonella infection. A prevalence of 41.5% (95%CI: 37.6–45.6%) was observed. Two major risk factors were significantly associated with Salmonella infection, both related to the pre-slaughter period (distance from the farm to the slaughterhouse and lairage time), highlighting the need to pay special attention to pre-slaughter practices in the province. Shortening transport times and complying with national regulations for lairage time at slaughter may help to reduce the prevalence of infection. Sixteen different serovars were identified, being S. Anatum and S. Typhimurium the most prevalent ones. Moreover, two isolate of the monophasic variant of Salmonella Typhimurium (I 4,5,12:i:-) resistant to enrofloxacin and which also displayed multidrug resistance was isolated for first time from pigs in Córdoba. The moderate to high levels of antimicrobial resistance detected for antibiotics commonly used in the pig sector suggested the need for implementing a plan to limit their use in the province.

Evaluation of the Coverage of 3 Antibiotic Regimens for Neonatal Sepsis in the Hospital Setting Across Asian Countries

High levels of antimicrobial resistance in neonatal bloodstream isolates are being reported globally, including in Asia. Local hospital antibiogram data may include too few isolates to meaningfully examine the expected coverage of antibiotic regimens. To assess the coverage offered by 3 antibiotic regimens for empirical treatment of neonatal sepsis in Asian countries. A decision analytical model was used to estimate coverage of 3 prespecified antibiotic regimens according to a weighted-incidence syndromic combination antibiogram. Relevant data to parameterize the models were identified from a systematic search of Ovid MEDLINE and Embase. Data from Asian countries published from 2014 onward were of interest. Only data on blood culture isolates from neonates with sepsis, bloodstream infection, or bacteremia reported from the relevant setting were included. Data analysis was performed from April 2019 to July 2019. The prespecified regimens of interest were aminopenicillin-gentamicin, third-generation cephalosporins (cefotaxime or ceftriaxone), and meropenem. The relative incidence of different bacteria and their antimicrobial susceptibility to antibiotics relevant for determining expected concordance with these regimens were extracted. Coverage was calculated on the basis of a decision-tree model incorporating relative bacterial incidence and antimicrobial susceptibility of relevant isolates. Data on 7 bacteria most commonly reported in the included studies were used for estimating coverage, which was reported at the country level. Data from 48 studies reporting on 10 countries and 8376 isolates were used. Individual countries reported 51 (Vietnam) to 6284 (India) isolates. Coverage varied considerably between countries. Meropenem was generally estimated to provide the highest coverage, ranging from 64.0% (95% credible interval [CrI], 62.6%-65.4%) in India to 90.6% (95% CrI, 86.2%-94.4%) in Cambodia, followed by aminopenicillin-gentamicin (from 35.9% [95% CrI, 27.7%-44.0%] in Indonesia to 81.0% [95% CrI, 71.1%-89.7%] in Laos) and cefotaxime or ceftriaxone (from 17.9% [95% CrI, 11.7%-24.7%] in Indonesia to 75.0% [95% CrI, 64.8%-84.1%] in Laos). Aminopenicillin-gentamicin coverage was lower than that of meropenem in all countries except Laos (81.0%; 95% CrI, 71.1%-89.7%) and Nepal (74.3%; 95% CrI, 70.3%-78.2%), where 95% CrIs for aminopenicillin-gentamicin and meropenem were overlapping. Third-generation cephalosporin coverage was lowest of the 3 regimens in all countries. The coverage difference between aminopenicillin-gentamicin and meropenem for countries with nonoverlapping 95% CrIs ranged from -15.9% in China to -52.9% in Indonesia. This study's findings suggest that noncarbapenem antibiotic regimens may provide limited coverage for empirical treatment of neonatal sepsis in many Asian countries. Alternative regimens must be studied to limit carbapenem consumption.

The dynamic of antibiotic resistance in commensal Escherichia coli throughout the growing period in broiler chickens: fast-growing vs. slow-growing breeds

Antimicrobial resistance (AMR) is an important threat to public health worldwide. Furthermore, different studies have demonstrated a close association between antibiotic use in animal production and AMR in humans. It is well known that it is necessary to reduce antibiotic administration in farms by finding effective alternative treatments, using more resistant breeds and improving animal welfare. However, to be able to assess the alternatives proposed, it is essential to study the epidemiology of AMR under production conditions. Hence, the aim of this study was to investigate the AMR dynamic in 2 genetic poultry breeds during the growing period. The study was performed in 2 experimental poultry houses to simulate real production conditions, and no antibiotics were administered during the growing period. In addition, 2 poultry breeds were used, fast-growing and slow-growing. To evaluate AMR evolution, Escherichia coli was selected as indicator bacterium. To this end, animals from each experimental group were sampled at different times: on day of arrival, at mid-period, and at slaughter day. In the laboratory, cecal content was removed and inoculated in selective media. Then, biochemical tests were performed to confirm E. coli. Finally, antibiotic susceptibility was assessed according to Decision 2013/653. At the onset of the cycle, significant differences were observed between breeds, as the E. coli strains isolated from fast-growing 1-day-old-chicks showed higher AMR rates. However, at the end of the period, no significant differences were found between breeds and their presence of resistant bacteria (above 95%). Therefore, although no antibiotics were administered during the growing period, a high level of AMR at slaughter day was demonstrated. Further studies are necessary to determine the main risk factors that increase the level of AMR throughout the productive cycle in broiler chickens. In conclusion, it is important to highlight that although it is crucial to control both antibiotic use and animal welfare during the growing period, measures should be taken at all levels of the production chain.

Prevalence, Risk Factors, and Antimicrobial Resistance Profiles of Thermophilic Campylobacter Species in Humans and Animals in Sub-Saharan Africa: A Systematic Review.

Thermophilic Campylobacter species are clinically important aetiologies of gastroenteritis in humans throughout the world. The colonization of different animal reservoirs by Campylobacter poses an important risk for humans through shedding of the pathogen in livestock waste and contamination of water sources, environment, and food. A review of published articles was conducted to obtain information on the prevalence and antimicrobial resistance (AMR) profiles of thermophilic Campylobacter species in humans and animals in sub-Saharan Africa (SSA). Electronic databases, namely, PubMed, Google Scholar, Research4life-HINARI Health, and Researchgate.net, were searched using the following search terms “thermophilic Campylobacter,” “Campylobacter jejuni,” “Campylobacter coli,” “diarrhea/diarrhoea,” “antimicrobial resistance,” “antibiotic resistance,” “humans,” “animals,” “Sub-Saharan Africa,” and “a specific country name.” Initially, a total of 614 articles were identified, and the lists of references were screened in which 22 more articles were identified. After screening, 33 articles on humans and 34 on animals and animal products were included in this review. In humans, Nigeria reported the highest prevalence (62.7%), followed by Malawi (21%) and South Africa (20.3%). For Campylobacter infections in under-five children, Kenya reported 16.4%, followed by Rwanda (15.5%) and Ethiopia (14.5%). The country-level mean prevalence in all ages and under-five children was 18.6% and 9.4%, respectively. The prevalence ranged from 1.7%–62.7% in humans and 1.2%–80% in animals. The most reported species were C. jejuni and C. coli. The AMR to commonly used antimicrobials ranged from 0–100% in both humans and animals. Poultry consumption and drinking surface water were the main risk factors for campylobacteriosis. The present review provides evidence of thermophilic Campylobacter occurrence in humans and animals and high levels of AMR in SSA, emphasizing the need for strengthening both national and regional multisectoral antimicrobial resistance standard surveillance protocols to curb both the campylobacteriosis burden and increase of antimicrobial resistance in the region.

Antimicrobial resistance, virulence factors, and molecular characterization of methicillin-resistant Staphylococcus aureus isolates cultured from ready-to-eat foods

To understand the antimicrobial resistance, virulence factors, and molecular characterization of MRSA isolates cultured from ready-to-eat(RTE) foods from several provinces in China. Totally, 397 S. aureus isolates were collected from RTE foods from several provinces in China, in 2017. The mecA gene was amplified to detect the MRSA strains among all 397 isolates by a polymerase chain reaction(PCR) method. Furthermore, the antimicrobial susceptibility and virulence factors of the MRSA isolates were detected by broth microdilution method and PCR, respectively, while the molecular characterization of all MRSA isolates were analyzed by pulsed-field gel electrophoresis(PFGE). In total, 32 MRSA isolates were identified from 397 isolates. All 32 MRSA isolates were resistant to penicillin, oxacillin and cefoxitin. Meanwhile, 78. 1%, 65. 6%, 53. 1, 28. 1% and 12. 5% of the 32 MRSA isolates showed resistant to erythromycin, clindamycin, tetracycline, chloramphenicol, and ciprofloxacin, respectively. Resistance rates to gentamicin and trimethoprim-sulfamethoxazole of all MRSA isolates were less than 10%. Eleven drug resistant spectrums were identified and 29 out of 32 MRSA isolates were identified as multi-drug resistant(MDR) isolates and two isolates were found to resistant to 9 antimicrobial agents tested in this study. Of all, 27 MRSA isolates were detected to harboring 13 virulence genes with sel-q(56. 3%), sel-k(43. 8%), seb(28. 1%) and sec(18. 8%) genes being the top four frequently detected. Besides, the result also showed that two or more virulence genes could be detected in one MRSA isolate. Finally, all 32 MRSA were identified to have 26 PFGE patterns and no dominant PFGE patterns were found in this study. An overall high level antimicrobial resistance was found among RTE associated MRSA in China in 2017, so was the MDR condition. Virulence genes could be frequently detected in RTE associated MRSA isolates. The PFGE patterns of RTE associated MRSA showed wide distribution characteristics.

Polysaccharide-Based Formulations for Healing of Skin-Related Wound Infections: Lessons from Animal Models and Clinical Trials.

Skin injuries constitute a gateway for pathogenic bacteria that can be either part of tissue microbiota or acquired from the environmental. These microorganisms (such as Acinetobacter baumannii, Enterococcus faecalis, Pseudomonas aeruginosa, and Staphylococcus aureus) produce virulence factors that impair tissue integrity and sustain the inflammatory phase leading for establishment of chronic wounds. The high levels of antimicrobial resistance have limited the therapeutic arsenal for combatting skin infections. Thus, the treatment of non-healing chronic wounds is a huge challenge for health services worldwide, imposing great socio-economic damage to the affected individuals. This scenario has encouraged the use of natural polymers, such as polysaccharide, in order to develop new formulations (membranes, nanoparticles, hydrogels, scaffolds) to be applied in the treatment of skin infections. In this non-exhaustive review, we discuss the applications of polysaccharide-based formulations in the healing of infected wounds in animal models and clinical trials. The formulations discussed in this review were prepared using alginate, cellulose, chitosan, and hyaluronic acid. In addition to have healing actions per se, these polysaccharide formulations can act as transdermal drug delivery systems, controlling the release of active ingredients (such as antimicrobial and healing agents). The papers show that these polysaccharides-based formulations are efficient in controlling infection and improve the healing, even in chronic infected wounds. These data should positively impact the design of new dressings to treat skin infections.

Structured surveillance of Achromobacter, Pandoraea and Ralstonia species from patients in England with cystic fibrosis

A structured survey of the cystic fibrosis pathogens Achromobacter, Pandoraea and Ralstonia species from thirteen sentinel hospitals throughout England was undertaken by Public Health England. One isolate per patient of these genera collected from CF patients during the seven-month survey period in 2015 was requested from participating hospitals. Species-level identification was performed using nrdA/gyrB sequence cluster analysis, and genotyping by pulsed-field gel electrophoresis. In total, 176 isolates were included in the survey; 138 Achromobacter spp. (78.4%), 29 Pandoraea spp. (16.5%) and 9 Ralstonia spp. (5.1%). Novel Achromobacter and Pandoraea clusters were identified. High levels of antimicrobial resistance were found, particularly among Pandoraea isolates. Genotyping analysis revealed considerable diversity, however one geographically-widespread cluster of A. xylosoxidans isolates from six hospitals was found, in addition to two other clusters, both comprising isolates from two hospitals, either derived from the same region (A. xylosoxidans), or from hospitals within the same city (P. apista).

Isolation, phenotypic and genotypic characterization of Escherichia coli from the bloodstream samples in Riyadh, Saudi Arabia

Bacteraemia is an international threat caused by extra-intestinal pathogenic Escherichia coli (ExPEC). Recently, the antimicrobial resistance of ExPEC has increased substantially, and this is attributed to the dissemination of E. coli ST131 clone. The present study explored the antimicrobial susceptibility patterns, extended spectrum β-lactamase (ESBL) carriage, virulence capacity and the prevalence of ST131 clone in Riyadh, Saudi Arabia. Thirty-one E. coli blood isolates, collected between January 2018 and March 2018, were used. The prevalence of ST131 clone was determined based on the PCR assays. Twenty-eight (90.3%) of all tested isolates were resistant to ampicillin, while only 1 isolate (3.2%) showed resistance to imipenem. Sixteen (51.6%) of the all isolates were ESBL producers, with CTX-M-15 being the predominant ESBL type. The virulence potential was higher among ESBL-producing isolates. Overall, seventeen (54.8%) isolates belonged to the ST131 clone. ST131 isolates were associated with increased antibiotic resistance; ESBL carriage and virulence capacity compared to non ST131isolates. This study reported the high levels of antimicrobial resistance and ESBL carriage among ExPEC blood isolates. It is concluded that the prevalence of ST131 clone among E. coli blood population is high locally, and found high virulence potential and antimicrobial resistance levels among ST131 isolates. These might drive ST131 success as a major cause of bacteraemia worldwide.

Natural immunity in conventionally and organically reared turkeys and its relation with antimicrobial resistance

Suboptimal animal welfare may affect natural immunity, rendering animals more susceptible to environmentally conditioned diseases, including those requiring antimicrobial treatment, which may promote antimicrobial resistance (AMR) in bacterial populations. Herewith, we tested the hypothesis that conventionally raised turkeys have higher levels of AMR in indicator Escherichia coli bacteria, but lower levels of natural immunity, as compared to turkeys reared under organic conditions. Litter and serum samples were collected from 28 conventional and 4 organic turkey farms: E. coli isolates from litter were tested for resistance to 14 antimicrobials, while 3 parameters of natural immunity (i.e., lysozyme, hemolytic complement levels, and serum bactericidal activity) were assessed in the sera. Resistant E. coli isolates were identified in both conventional and organic farms but generally more frequently in conventional farms. High rates of resistance to ampicillin (96%), tetracycline (95%), streptomycin (82%), sulfamethoxazole (80%), ciprofloxacin (73%), and trimethoprim (71%), as well as high rates of multiresistance, were observed in conventional farms. Organically raised turkeys had significantly higher levels of lysozyme and serum bactericidal activity than conventional turkeys, and these levels were also higher in turkeys housed in farms where AMR frequency was lower. Findings support the hypothesis that conventional farming conditions may affect turkeys' natural immunity, rendering the animals more susceptible to environmentally conditioned diseases requiring antimicrobial treatment, which would in turn promote AMR. Reducing AMR in turkey farming is therefore more likely to be successful when considering animal welfare as an option to reduce the need of antimicrobial use.

Antimicrobial Effects Caused by Aloe barbadensis Miller on Bacteria Associated with Mastitis in Dairy Cattle

It is known that the primary etiological agents associated with bovine mastitis show high levels of antimicrobial resistance. In this paper, we studied a possible alternative to antimicrobial treatment, Aloe barbadensis Miller ( A. vera). Our goal was to determine the viability of bacteria upon treatment with a methanolic extract of A. vera gel, rich in anthraquinones such as aloin A, aloin B, and aloe emodin. To this purpose, we used fluorescence spectrometry to study the following bacteria: Staphylococcus aureus, Escherichia coli, Streptococcus uberis, and Methicillin-resistant Staphylococcus aureus (MRSA). The results show that treatment with A. vera gel extract disrupted the cell membrane causing lysis in 75% of Staphylococcus aureus, in 88% of E. coli, in 97% of Streptococcus uberis, and in 88% of MRSA cells. Cell membrane disruption is attributed to the presence of anthraquinones. Further study is needed to determine whether other phenolic compounds present in the extract, influencing antimicrobial activity, could be used to develop pharmaceutical formulations to treat bovine mastitis.