Antimicrobial-resistant Organisms Research Articles

Antimicrobial Resistance and ARGs Detection in Treated Final Effluent from STPs: An Upcoming Challenge to the Environment

Aim: The present study analysed the presence of antimicrobial resistance organisms and genes in the final effluent from STPs of hospitals. Study Area and Sampling: Samples for microbiological analysis were collected from two different hospitals in Trivandrum City and carried out further microbiological analysis. Methodology: In this study, MDRB (Multi Drug Resiatant Bacteria) were detected from the hospital effluent samples collected from two hospitals. Antibiotic susceptibility analysis showed that the 90% screened organisms was resistant to different antibiotics -Tetracycline (30µg), Amikacin (30µg), Gentamycin (10µg), Ciprofloxacin (5µg), Colistin (10µg) and Amoxicillin (30µg)). Metagenomic surveillance of effluent helped to assess the efficacy of STPs, at the same time assessing the local clinical antibiotic resistance condition by detection of the presence of antimicrobial resistance towards antibiotics and their genes (ARGs) in the hospital effluent. Results: In this study, a total of 3 antibiotic resistant bacterial strains obtained from hospital STP effluent were identified by16S rRNA sequence analysis. The sequences of E.coli, Klebsiella and Enterobacter were submitted in Genbank with accession number MT784125, OM978270 andMN437586 respectively.The final effluent from Hospital 1 showed100% resistance to Tetracycline and 86% resistance to Amoxicillin followed by sensitivity 28%, 22%, 18% and 10% respectively to Ciprofloxacin, Gentamycin, Amikacin and Colistin. The bacterial strains isolated from final effluent of Hospital 2 showed highest resistance to Amikacin and Colistin which is 100% and 86% and 82% resistance to Gentamycin and Ciprofloxacin. The gene primers used for the respective genes above have been amplified in the sample with a higher efficiency of 16 SrRNA, ermB and ampC primers showing a lower Cq value. Thus, these three genes were detected in the samples at high amount which showed the prominent use of the consecutive antibiotics in the clinical field

A rare case of urinary tract infection by Burkholderia cepacia

Burkholderia cepacia is a motile, aerobic, non-fermentative, gram-negative bacillus and has been widely documented as a lung pathogen in patients with cystic fibrosis and chronic granulomatous disease. It is documented as an important emerging cause of multi-drug resistant nosocomial infections, and an important cause of morbidity and mortality. A 64-year-old male patient visited the Nikea Primary Healthcare Center, Piraeus, Greece, referred by the family doctor (GP), for follow-up due a history of prostate cancer (patient on immunosuppression) and recurrent UTIs with subsequent admission to the hospital. Patient history revealed diabetes mellitus type 2, arterial hypertension, hypercholesterolemia, hypertriglyceridemia, history of recurrent UTIs, with 4 hospitalizations in a tertiary hospital during the last 2 years, prostatic hypertrophy, 2 episodes of prostatitis before the diagnosis of prostate cancer Gleason score 6, at the end of 2019, with subsequent total prostatectomy, and radiotherapy. Patient history also revealed dysuria, frequent urination, pain and burning sensation during urination and erectile dysfunction. Urinalysis showed intense pyuria, abundance of micro-organisms and abundance of red blood cells. The urine culture grew monomicrobial Burkholderia cepacia 105 CFU/ml. The bacterium was identified by the RapID™ REMEL ONE identification system (Thermo Fisher Scientific). Antimicrobial susceptibility testing revealed susceptibility to antibiotics such as, Ceftazidime, Ciprofloxacin, Norfloxacin, Levofloxacin and Imipenem.The patient received treatment with Levofloxacin. Burkholderia cepacia infections outside the respiratory system are rare. Moreover, recurrent UTIs with B. cepacia is a rare finding, which highlights the importance of our study. UTIs with B. cepacia have been associated with bladder irrigation or use of contaminated hospital objects and liquids. B. cepacia is one of the most antimicrobial-resistant organisms and treatment options are limited. The patient was treated with Levofloxacin (3rd generation fluoroquinolone — Tavanic) 500 mg daily per os for 2 weeks, due to his history.

The Antimicrobial and Antibiofilm Abilities of Fish Oil Derived Polyunsaturated Fatty Acids and Manuka Honey.

Both honey and fish oil have been historically used in medicine and identified as having antimicrobial properties. Although analyses of the substances have identified different components within them, it is not fully understood how these components interact and contribute to the observed effect. With the increase in multi-drug resistant strains of bacteria found in infections, new treatment options are needed. This study aimed to assess the antimicrobial abilities of fish oil components, including docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and derived resolvins (RvE1, RvD2, and RvD3), as well as two varieties of manuka honey, against a panel of medically relevant microorganisms and antimicrobial resistant organisms, such as Methicillin Resistant Staphylococcus aureus (MRSA) and carbapenem-resistant Escherichia coli. Minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) were identified; further minimum biofilm eradication concentrations (MBEC) were investigated for responsive organisms, including S. aureus, E. coli, Staphylococcus epidermidis, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Concurrent with the existing literature, manuka honey was found to be a broad-spectrum antimicrobial with varied potency according to methylglyoxal content. DHA and EPA were both effective against Gram-positive and negative bacteria, but some drug-resistant strains or pathogens were not protected by a capsule. Only E. coli was inhibited by the resolvins.

Active surveillance of antimicrobial resistance in companion animals: A pilot study in a Spanish Veterinary Teaching Hospital

The role of small animal veterinary hospitals in the onset and dissemination of antimicrobial-resistant organisms (AMROs) is still not clear, and the implementation of an internal surveillance systems is a cost-effective tool to better understand their impact. The aim of this study was to describe a pilot program of active surveillance in a Spanish Veterinary Teaching Hospital, developed to estimate the detection frequency of AMROs in the commensal flora of patients and in the environment. Surveillance was focused on Methicillin-resistant Staphylococci (MRS), third generation cephalosporins resistant gram-negative bacteria (3GCR-GNB), and carbapenems-resistant gram-negative bacteria (CR-GNB). Oral and perirectal swabs were collected in the same dogs and cats hospitalized > 48 h, at their admission and before their discharge. Out of 50 patients sampled, 24% (12/50) were carriers at admission of at least one of the three investigated AMROs. Twenty-eight percent of patients (14/50) acquired at least one AMRO during the hospital stay. MRS detection frequency at admission was 12% (6/50), while acquisition was 6% (3/50). 3GCR-GNB detection frequency was 14% at admission (7/50) and acquisition 22% (11/50), while CR-GNB detection frequency was 2% at admission (1/50) and acquisition 2% (1/50). Environmental surveillance (98 samples) showed a total detection frequency of 22.4% for MRS (22/98), 2% for 3GCR-GNB and CR-GNB (2/98). Clinical staff’ shoe soles showed high detection frequency for MRS (50%). 3GCR Escherichia coli was the most isolated species in patients (n = 17). The results show how active surveillance can be used as a tool to assess the impact of AMROs in veterinary hospitals to subsequently build up tailored control plans based on specific issues.

Extended Spectrum Beta Lactamase Escherichia Coli in Bagmati River, Kathmandu Valley.

Antimicrobial resistance organisms in the peripheral communities of an environment can be predicted by the presence of extended-spectrum beta-lactamase Escherichia coli in that environment. The close connectivity between humans and water sources can facilitate the entry of antimicrobial resistant organisms into the human ecosystem. The aim of this study was to assess beta lactamase producing Escherichia coli from Bagmati river within Kathmandu valley. In the year 2020, a cross-sectional study was conducted on water samples collected from 66 locations along the Bagmati River. Coliforms were isolated by five tubes dilution method and identified by cultural and biochemical tests. Further Escherichia coli was isolated in eosin methylene blue agar at 44.5 ⁰C. Antibiotic susceptibility test was performed by Kirby Bauer disk diffusion methods. Beta lactamase gene types were detected by using conventional multiplex polymerase chain reaction. A total of 615 bacterial isolates were identified among which 39 % (n=241) were Escherichia coli. Extended spectrum beta lactamase producing Escherichia coli was confirmed in 16.6 % (40/241) of total Escherichia coli isolates. Among 66 sites this isolate was detected in 26 (40 %) sampling sites excluding upstream regions. All the Escherichia coli isolates were multidrug resistance showing higher percentage (>99 %) of resistant for penicillin, tetracycline and erythromycin antibiotics. There were significant differences in resistance rate for cefotaxime and ceftazidime by extended spectrum beta lactamase producing and non-producing Escherichia coli (p<0.05). Presence of multidrug resistance extended spectrum beta lactamase producing Escherichia coli in river streams suggests the chances of circulating within river system and hence transmitting in human community. Bagmati river; drug resistance; escherichia coli; human.

Epidemiology of healthcare-associated Pseudomonas aeruginosa in intensive care units: are sink drains to blame?

Pseudomonas aeruginosa (PA) is a common cause of healthcare-associated infections (PA-HAI) in the intensive care unit (ICU). We aimed to describe the epidemiology of PA-HAI in ICUs in Ontario, Canada, and determine whether we could identify episodes of sink-to-patient PA transmission. This was a prospective cohort study of patients in six ICUs from 2018-2019, with retrieval of PA clinical isolates, and PA-screening of antimicrobial resistant organism surveillance rectal swabs, and of sink drain, air, and faucet samples. All PA isolates underwent whole genome sequencing. PA-HAI was defined using US National Healthcare Safety Network criteria. ICU-acquired PA was defined as PA isolated from specimens obtained >48 hours after ICU admission in those with prior negative rectal swabs. Sink-to-patient PA transmission was defined as ICU-acquired PA with close genomic relationship to isolate(s) previously recovered from sinks in a room/bedspace occupied 3-14 days prior to the relevant patient isolate. Over ten months, 72 PA-HAI occurred among 60/4263 admissions. The rate of PA-HAI was 2.40 per 1000 patient-ICU days; higher in patients who were PA-colonized on admission. PA-HAI was associated with longer stay (median 26 vs 3 days uninfected, p<0.001) and contributed to death in 22/60 cases (36.7%). Fifty-eight admissions with ICU-acquired PA were identified, contributing 35/72 (48.6%) PA-HAI. Four patients with five PA-HAI (6.9%) had closely related isolates previously recovered from their room/bedspace sinks. Nearly half of PA causing HAI appeared to be acquired in ICUs, and 7% of PA-HAI were associated with sink-to-patient transmission. Sinks may be an underrecognized reservoir for HAIs.

Unusual and complicated peritonitis: Your questions answered.

Effective treatment of infections is a growing challenge owing to antimicrobial resistance. Peritoneal dialysis (PD) patients experience more frequent hospitalisations than the general population and have greater exposure to antibiotics, making them particularly vulnerable to this threat. Over the last decade, we have noted a surge in cases of complicated peritoneal dialysis-associated peritonitis (PD peritonitis) caused by antimicrobial-resistant organisms, including extended-spectrum beta-lactamase (ESBL), AmpC beta-lactamase-producing Enterobacterales, Pseudomonas aeruginosa and fungi. Practitioners must be alert to these organisms, seek early recognition of these resistance patterns and make timely adjustments in order to avoid delay in treatment that may increase risk of PD catheter removal and technique failure. We present a case of successful treatment of ESBL peritonitis, highlight its challenges, while providing guidance on management of other unusual and complicated PD peritonitis.

Adopting telemedicine in the fight against antimicrobial resistance in West Africa.

The detrimental effects of antimicrobial resistance (AMR) have called for several approaches in the fight against it in West Africa, where telemedicine is still in its infancy. In West Africa, self-medication is prevalent because the majority of these medications are easily accessible due to insufficient regulatory structures that control their production, distribution, and consumption. Also, access to healthcare facilities and professionals is limited. All of these and other inadequacies consequently result in the emergence of antimicrobial-resistant organisms. AMR, which is now a major global health crisis according to the WHO, may cause the deaths of about 10 million people before 2050, and Africa may make up 41% of these deaths, with the Western part of this continent affected the most. While several approaches have been adopted, unlike in other regions of the world, the use of telemedicine in West Africa to fight AMR has rarely been studied or considered and where it is now in partial use, its efficacy is constrained by several factors. This paper discusses the roles of telemedicine, the limitations to its application in the fight against AMR, and suggests remedies for these limitations.

Sanitation in urban areas may limit the spread of antimicrobial resistance via flies.

Synanthropic filth flies are common where sanitation is poor and fecal wastes are accessible to them. These flies have been proposed as mechanical vectors for the localized transport of fecal microbes including antimicrobial resistant (AMR) organisms and associated antimicrobial resistance genes (ARGs), increasing exposure risks. We evaluated whether an onsite sanitation intervention in Maputo, Mozambique reduced the concentration of enteric bacteria and the frequency of detection of ARGs carried by flies collected in household compounds of low-income neighborhoods. Additionally, we assessed the phenotypic resistance profile of Enterobacteriaceae isolates recovered from flies during the pre-intervention phase. After fly enumeration at study compounds, quantitative polymerase chain reaction was used to quantify an enteric 16S rRNA gene (i.e., specific to a cluster of phylotypes corresponding to 5% of the human fecal microflora), 28 ARGs, and Kirby Bauer Disk Diffusion of Enterobacteriaceae isolates was utilized to assess resistance to eleven clinically relevant antibiotics. The intervention was associated with a 1.5 log10 reduction (95% confidence interval: -0.73, -2.3) in the concentration of the enteric 16S gene and a 31% reduction (adjusted prevalence ratio = 0.69, [0.52, 0.92]) in the mean number of ARGs per fly compared to a control group with poor sanitation. This protective effect was consistent across the six ARG classes that we detected. Enterobacteriaceae isolates-only from the pre-intervention phase-were resistant to a mean of 3.4 antibiotics out of the eleven assessed. Improving onsite sanitation infrastructure in low-income informal settlements may help reduce fly-mediated transmission of enteric bacteria and the ARGs carried by them.

Enhancing competency in infection prevention and control: Identifying priorities for clinical nurse educational needs

BackgroundHealthcare-associated infections (HAIs) have become a significant concern globally, posing risks to patients and imposing social and economic burdens. Competency in infection prevention and control (IPC) practices is essential for nurses to effectively reduce the risk of transmission. However, there is a lack of research on educational needs for competency in IPC practices. ObjectivesThis study aimed to assess and prioritize educational needs for the development of educational content focused on the IPC practices of clinical nurses. DesignA descriptive cross-sectional design was utilized. SettingsThis study was conducted at six general hospitals located in five urban regions in South Korea, each with 100 to 300 beds. ParticipantsA total of 226 nurses were recruited as participants for this study. MethodsData were collected from June to July 2021. A total of 226 nurses participated in this study. After examining the perceived importance and current performance of attributes related to IPC, educational needs were identified by paired-sample t-test, importance-performance analysis, Borich's needs analysis, and the Locus for Focus model. ResultsItems related to IPC were found to have lower performance than importance, highlighting the need for education. Educational needs were the highest for items in the “IPC practices according to microorganisms” category, such as MRSA, VRE, antimicrobial-resistant organisms, Clostridium difficile, scabies, and AIDS. Items in the “isolation precautions” category, including standard precautions, transmission-based precautions, management of isolation rooms, and wearing PPE, also demonstrated high priority in terms of educational needs. The findings suggest the need for training programs for clinical nurses with a focus on specific areas for improving IPC competency. ConclusionsThe development and implementation of training modules tailored to the educational needs of clinical nurses may enhance their skills, knowledge, and attitudes, ultimately resulting in improved performance.

Exploring Antimicrobial Resistance Profiles of E. coli Isolates in Dairy Cattle: A Baseline Study across Dairy Farms with Varied Husbandry Practices in Puerto Rico.

Antimicrobial treatment in livestock can contribute to the emergence and spread of antimicrobial-resistant (AMR) microorganisms. Despite substantial surveillance of AMR bacteria in the continental United States, the prevalence of these AMR organisms in U.S. territories, such as Puerto Rico, remains understudied. The goals of this research included obtaining baseline data on the antimicrobial profile of E. coli isolates from Puerto Rico dairy farms with different husbandry practices. Seventy-nine fecal samples were collected from two types of conventional dairy farms: those that fed calves with tank milk and those that fed calves with waste milk. These samples were collected from the animals' rectums, culture, and subsequently confirmed through biochemical tests. Out of these samples, 32 isolates were analyzed phenotypically and genotypically to elucidate their AMR profiles. The results underscore a discrepancy in the occurrence of antimicrobial resistance genes between calves and adult cattle. Notably, waste milk-fed calves exhibited a significantly higher prevalence of antibiotic-resistant E. coli when compared to their tank milk-fed counterparts. These disparities emphasize the need for more comprehensive investigations to determine causative factors. These results underscore the urgency of comprehensive strategies to raise awareness about how management practices influence antimicrobial resistance, shifting the focus from treatment to prevention.

565. Antimicrobial susceptibility profiles of Acinetobacter species in blood: 10-year experience from a major United States reference laboratory

Abstract Background Antimicrobial resistance (AMR) is a threat to healthcare, and infections with antimicrobial resistant organisms carry significant morbidity and mortality. Owing to high rates of AMR, the Centers for Disease Control and Prevention listed Acinetobacter baumannii as a top priority pathogen for research and development of new antimicrobial agents. Antimicrobial susceptibility testing is challenging for this organism, and susceptibility profiles are variable, leading to need of a potential guidance document with assistance in selecting effective empiric therapeutic regimens. Methods We retrospectively reviewed the microbiology and antimicrobial susceptibility testing (AST) results for Acinetobacter spp. from blood culture isolates submitted to Mayo Clinic Laboratories from December 2012 to 2022. AST was performed using agar dilution and interpretations following Clinical &amp; Laboratory Standards Institute (CLSI) guidelines. Isolates were identified by MALDI mass spectrometry and/or 16S sequencing, as available (Figure 1).Figure 1:Isolate identification Isolate identification description. Isolates were analyzed based on this classification used in out laboratory. Results 804 blood culture isolates were included. A. baumannii/calcoaceticus complex (27%) was most frequently isolated, followed by A. lwoffii (22%), and showed the highest resistance across all antimicrobials (73% susceptible or below) (Figure 2). A. baumannii/calcoaceticus complex showed rising resistance rates over time from 2012 to 2022 for meropenem, minocycline and ampicillin-sulbactam (Figure 3). Cefiderocol non-susceptible rate was 35% for A. baumannii/calcoaceticus complex.Figure 2:Antimicrobial susceptibility profiles for Acinetobacter spp. Description of susceptibility profiles for Acinetobacter spp. isolates, based on the classification used by our laboratory. Antimicrobials are presented at the top and isolates on the left. Number of isolates analyzed are presented in the table with the percentage of the isolates susceptible to each antibiotic class in parenthesis.Figure 3:Acinetobacter baumannii/calcoaceticus complex isolates and resistance, trend Trend of isolates per year and resistance percentage to meropenem, colistin, minocycline and amp-sulb. Number of isolates per year at the base of each bar; percentage of resistance for antimicrobials expressed on lines. Amp-sulb = ampicillin-sulbactam. Conclusion A. baumannii/calcoaceticus complex showed high levels of resistance ( &amp;gt;75%) across multiple antimicrobials and increasing rates of resistance over time from 2012 to 2022. A high number of cefiderocol non-susceptible organisms is also concerning (Figure 2). Disclosures Audrey N. Schuetz, MD, Merck: Advisor/Consultant

1272. Teaching the ABCs of ASB in a 60-minute educational intervention. A quality improvement project.

Abstract Background Asymptomatic bacteriuria (ASB) refers to the presence of bacteria in the urine of individuals that do not present with symptoms of urinary tract infection (UTI). Treatment for ASB is not recommended in most cases. [1] Previous studies have shown that provider education on proper antibiotic use has been effective in mitigating the ongoing wave of antimicrobial-resistant organisms across hospitals in the United States.[2] We aimed to decrease the proportion of cases classified as having asymptomatic bacteria by 20% in four months after the intervention using a small group discussion and a presentation. Methods We evaluated the rates of inappropriate antimicrobial prescribing for asymptomatic bacteriuria (ASB) for 4 months before educational intervention and 4 months after. Data was extracted from the electronic medical record (Cerner®), imported into REDCap®, and with standardized manual chart review. Data analysis was completed using STATA® 17 &amp; 18. Results The mean duration of antibiotic therapy was 7.9 days in the pre-intervention group and 6.1 days in the post-intervention group. See Table 1 for more details on demographics. Following the intervention, the rate of inappropriate use of antimicrobial therapy in ASB was reduced by 29.8% (p-value 0.035). The mean duration of antibiotic therapy decreased by almost 2 days in the post-intervention group. Conclusion This quality improvement project suggests that focused interventions of short interactive educational sessions in small groups may reduce the inappropriate use of antibiotics in ASB by almost 30%. The mean duration in days of antibiotic treatment decreased from 7.9 days to 6.1 days in the pre and post-intervention groups (p-value 0.060). Of note the total number of cases with providers selecting UTI as an indication was also lower in the post-intervention group and although we can’t determine causality, it provided evidence of a lower number of cases, providers initially classified as UTI between the pre and post-intervention period from 33 to 19. Further research may include incorporating small groups and interprofessional educational interventions to help implement good antimicrobial stewardship in inpatient care facilities. [4,5,6] Disclosures All Authors: No reported disclosures

Characterization of exclusively non-commensal Neisseria gonorrhoeae pangenome to prioritize globally conserved and thermodynamically stable vaccine candidates using immune-molecular dynamic simulations

Neisseria gonorrhoeae (Ngo) has emerged as a global threat leading to one of the most common sexually transmitted diseases in the world. It has also become one of the leading antimicrobial resistant organisms, resulting in fewer treatment options and an increased morbidity. Therefore, in recent years, there has been an increased focus on the development of new treatments and preventive strategies to combat its infection. In this study, we have combined the most conserved epitopes from the completely assembled strains of Ngo to develop a universal and a thermodynamically stable vaccine candidate. For our vaccine design, the epitopes were selected for their high immunogenicity, non-allergenicity and non-cytotoxicity, making them the ideal candidates for vaccine development. For the screening process, several reverse vaccinology tools were employed to rigorously extract non-homologous and immunogenic epitopes from the selected proteins. Consequently, a total number of 3 B-cell epitopes and 6 T-cell epitopes were selected and joined by multiple immune-modulating adjuvants and linkers to generate a promiscuous immune response. Additionally, the stability and flexible nature of the vaccine construct was confirmed using various molecular dynamic simulation tools. Overall, the vaccine candidate showed promising binding affinity to various HLA alleles and TLR receptors; however, further studies are needed to assess its efficacy in-vivo. In this way, we have designed a multi-subunit vaccine candidate to potentially combat and control the spread of N. gonorrhoeae.

CAUTI Elimination: A Systematic Elimination of CAUTI in Long-Term Care Facility

Catheter-associated urinary tract infection (CAUTI) in nursing-home residents is commonly associated with multiple problems. Lack of proper intervention to prevent CAUTI in the elderly and frail nursing-home residents leads to sepsis, hospitalization, and antimicrobial use, ultimately causing the colonization with multidrug- resistant organisms (MDROs). Furthermore, it inflates the costs. The project aims to systematically determine an approach to eliminate CAUTI in long-term care facilities. There, the establishment of antibiotic stewardship is at its infancy stage. The CAUTI project contributes significantly to the wide-reaching efforts to reduce the threats posed by antimicrobial-resistant organisms. The crucial element of an impactful strategy is the prevention by utilizing evidence-based bundle of care education and evidence-based urinary catheter protocols (UCP), both funded by the Agency for Healthcare Research and Quality (AHRQ). The CAUTI project’s outcome is measured using National Healthcare Safety Network (NHSN) and the symptomatic definition of CAUTI provided by the Centers for Disease Control and Prevention (CDC) to identify and count the cases in the unit; the team uses the NHSN’s data for benchmarking. The qualitative and quantitative methodology approaches utilized to implement a CAUTI prevention strategy at Burbank Healthcare Center and Rehabilitation. Thirty participants were selected out of 172 populations during the study for the CAUTI project. The findings indicate that 11 out of 30 participants developed CAUTI, of which three acquired it at the facility and eight at the community. Further, although female participants were fewer than males, females seem to develop a CAUTI with higher frequency than male participants.

Detection of Antimicrobial-Resistant Organisms (AMROs) and Related Factors for AMROs Colonization in Long-term Care Facilities

Detection of Antimicrobial-Resistant Organisms (AMROs) and Related Factors for AMROs Colonization in Long-term Care Facilities

Planktonic and epilithic prokaryota community compositions in a large temperate river reflect climate change related seasonal shifts.

In freshwaters, microbial communities are of outstanding importance both from ecological and public health perspectives, however, they are threatened by the impact of global warming. To reveal how different prokaryotic communities in a large temperate river respond to environment conditions related to climate change, the present study provides the first detailed insight into the composition and spatial and year-round temporal variations of planktonic and epilithic prokaryotic community. Microbial diversity was studied using high-throughput next generation amplicon sequencing. Sampling was carried out monthly in the midstream and the littoral zone of the Danube, upstream and downstream from a large urban area. Result demonstrated that river habitats predominantly determine the taxonomic composition of the microbiota; diverse and well-differentiated microbial communities developed in water and epilithon, with higher variance in the latter. The composition of bacterioplankton clearly followed the prolongation of the summer resulting from climate change, while the epilithon community was less responsive. Rising water temperatures was associated with increased abundances of many taxa (such as phylum Actinobacteria, class Gammaproteobacteria and orders Synechococcales, Alteromonadales, Chitinophagales, Pseudomonadales, Rhizobiales and Xanthomonadales), and the composition of the microbiota also reflected changes of several further environmental factors (such as turbidity, TOC, electric conductivity, pH and the concentration of phosphate, sulphate, nitrate, total nitrogen and the dissolved oxygen). The results indicate that shift in microbial community responding to changing environment may be of crucial importance in the decomposition of organic compounds (including pollutants and xenobiotics), the transformation and accumulation of heavy metals and the occurrence of pathogens or antimicrobial resistant organisms.

Gut microbiome perturbation, antibiotic resistance, and Escherichia coli strain dynamics associated with international travel: a metagenomic analysis

Culture-based studies have shown that acquisition of extended-spectrum β-lactamase-producing Enterobacterales is common during international travel; however, little is known about the role of the gut microbiome before and during travel, nor about acquisition of other antimicrobial-resistant organisms. We aimed to identify (1) whether the gut microbiome provided colonisation resistance against antimicrobial-resistant organism acquisition, (2) the effect of travel and travel behaviours on the gut microbiome, and (3) the scale and global heterogeneity of antimicrobial-resistant organism acquisition. In this metagenomic analysis, participants were recruited at three US travel clinics (Boston, MA; New York, NY; and Salt Lake City, UT) before international travel. Participants had to travel internationally between Dec 8, 2017, and April 30, 2019, and have DNA extractions for stool samples both before and after travel for inclusion. Participants were excluded if they had at least one low coverage sample (<1 million read pairs). Stool samples were collected at home before and after travel, sent to a clinical microbiology laboratory to be screened for three target antimicrobial-resistant organisms (extended-spectrum β-lactamase-producing Enterobacterales, carbapenem-resistant Enterobacterales, and mcr-mediated colistin-resistant Enterobacterales), and underwent DNA extraction and shotgun metagenomic sequencing. We profiled metagenomes for taxonomic composition, antibiotic-resistant gene content, and characterised the Escherichia coli population at the strain level. We analysed pre-travel samples to identify the gut microbiome risk factors associated with acquisition of the three targeted antimicrobial resistant organisms. Pre-travel and post-travel samples were compared to identify microbiome and resistome perturbation and E coli strain acquisition associated with travel. A total of 368 individuals travelled between the required dates, and 296 had DNA extractions available for both before and after travel. 29 travellers were excluded as they had at least one low coverage sample, leaving a final group of 267 participants. We observed a perturbation of the gut microbiota, characterised by a significant depletion of microbial diversity and enrichment of the Enterobacteriaceae family. Metagenomic strain tracking confirmed that 67% of travellers acquired new strains of E coli during travel that were phylogenetically distinct from their pre-travel strains. We observed widespread enrichment of antibiotic-resistant genes in the gut, with a median 15% (95% CI 10-20, p<1 × 10-10) increase in burden (reads per kilobase per million reads). This increase included antibiotic-resistant genes previously classified as threats to public health, which were 56% (95% CI 36-91, p=2 × 10-11) higher in abundance after travel than before. Fluoroquinolone antibiotic-resistant genes were aquired by 97 (54%) of 181 travellers with no detected pre-travel carriage. Although we found that visiting friends or relatives, travel to south Asia, and eating uncooked vegetables were risk factors for acquisition of the three targeted antimicrobial resistant organisms, we did not observe an association between the pre-travel microbiome structure and travel-related antimicrobial-resistant organism acquisition. This work highlights a scale of E coli and antimicrobial-resistant organism acquisition by US travellers not apparent from previous culture-based studies, and suggests that strategies to control antimicrobial-resistant organisms addressing international traveller behaviour, rather than modulating the gut microbiome, could be worthwhile. US Centers for Disease Control and Prevention and National Institute of Allergy and Infectious Diseases.

Antimicrobial Susceptibility Patterns: A Four Year (2017-2020) Surveillance Study at a Tertiary Acute Care Hospital in Saudi Arabia

Introduction Objective To analyze the antimicrobial susceptibility patterns in a four years period (2017-2020) at a tertiary acute care hospital in Kingdom of Saudi Arabia. Methods This is a retrospective observational study on a total 28214 pathogens isolated and shown in antibiograms between 2017 and 2020 at tertiary acute care King Salman Armed Forces Hospital Tabuk, Kingdom of Saudi Arabia. Results The four-year (2017-2020) retrospective observational study analyzed antibiograms at King Salman Armed Forces Hospital Tabuk, Saudi Arabia . Among the six most common organisms isolated, Escherichia coli was the most prevalent Gram-negative species, and Staphylococcus aureus was the dominant Gram-positive species. The study revealed an upward trend in antimicrobial resistance, emphasizing the need for strict infection control measures and prudent antibiotic use to combat the rising resistance Conclusion There has been an upward trend in the development of antimicrobial resistant organisms as observed in our study which is in agreement with other local studies showing same trends

Gut microbiology of UK care home residents: a cross-sectional analysis from a randomised controlled trial

ObjectiveTo describe the prevalence of potentially clinically relevant gut pathogens and associations with the carriage of resistant organisms in UK care home residents. MethodsStool samples were collected pre-randomisation from care home residents participating in a randomised placebo-controlled trial. Cultivable clinically relevant bacteria were analysed. Antimicrobial susceptibility testing was performed by agar dilution (amoxicillin, co-amoxiclav, gentamicin, trimethoprim, nitrofurantoin, and ciprofloxacin). We also aimed to detect resistance to third-generation cephalosporins, carbapenems, and vancomycin. ResultsStool samples were available for 159/310 residents participating in the trial (51%) from 23 care homes between 2016 and 2018. In total, 402 bacterial isolates were cultured from 158 stool samples and 29 different species were cultured. The five most common species were Escherichia coli (155/158, 98%), Pseudomonas aeruginosa (40/158, 25%), Enterococcus faecalis (35/158, 22%), Enterococcus faecium (30/158, 19%), and Proteus mirabilis (25/158, 16%). Enterobacterales isolates were cultured from 157 samples (99%), and resistance to at least one of the tested antimicrobials was found in 119 of these (76%). There were high levels of variation in outcomes by care home. DiscussionWe demonstrated that care home residents harbour significant levels of antimicrobial-resistant organisms in their stool. This work emphasises the importance of both enhanced infection control practices and antimicrobial stewardship programmes to support the appropriate use of antimicrobials in this setting.