Prevalence Of Antimicrobial Resistance Research Articles

Inferring diet, disease and antibiotic resistance from ancient human oral microbiomes.

The interaction between a host and its microbiome is an area of intense study. For the human host, it is known that the various body-site-associated microbiomes impact heavily on health and disease states. For instance, the oral microbiome is a source of various pathogens and potential antibiotic resistance gene pools. The effect of historical changes to the human host and environment to the associated microbiome, however, has been less well explored. In this review, we characterize several historical and prehistoric events which are considered to have impacted the oral environment and therefore the bacterial communities residing within it. The link between evolutionary changes to the oral microbiota and the significant societal and behavioural changes occurring during the pre-Neolithic, Agricultural Revolution, Industrial Revolution and Antibiotic Era is outlined. While previous studies suggest the functional profile of these communities may have shifted over the centuries, there is currently a gap in knowledge that needs to be filled. Biomolecular archaeological evidence of innate antimicrobial resistance within the oral microbiome shows an increase in the abundance of antimicrobial resistance genes since the advent and widespread use of antibiotics in the modern era. Nevertheless, a lack of research into the prevalence and evolution of antimicrobial resistance within the oral microbiome throughout history hinders our ability to combat antimicrobial resistance in the modern era.

Predictive statistical models for monitoring antimicrobial resistance spread in the environment using Apis mellifera (L. 1758) colonies

The rise of antimicrobial resistance (AMR) is one of the most relevant problems for human and animal health. According to One Health Approach, it is important to regulate the use of antimicrobials and monitor the spread of AMR in the environment as well. Apis mellifera (L. 1758) colonies were used as bioindicators thanks to their physical and behavioural characteristics. During their foraging flights, bees can intercept small particles, including atmospheric particulate matter, etc., and also microorganisms. To date, the antimicrobial surveillance network is limited to the sanitary level but lacks into environmental context. This study aimed to evaluate the use of A. mellifera colonies distributed throughout the Emilia-Romagna region (Italy) as indicators of environmental antimicrobial-resistant bacteria. This was performed by creating a statistical predictive model that establishes correlations between environmental characteristics and the likelihood of isolating specific bacterial genera and antimicrobial-resistant strains. A total of 608 strains were isolated and tested for susceptibility to 19 different antimicrobials. Aztreonam-resistant strains were significantly related to environments with sanitary structures, agricultural areas and wetlands, while urban areas present a higher probability of trimethoprim/sulfamethoxazole-resistant strains isolation. Concerning genera, environments with sanitary structures and wetlands are significantly related to the genera Proteus spp., while the Escherichia spp. strains can be probably isolated in industrial environments. The obtained models showed maximum values of Models Accuracy and robustness (R2) of 55 % and 24 %, respectively. The results indicate the efficacy of utilizing A. mellifera colonies as valuable bioindicators for estimating the prevalence of AMR in environmentally disseminated bacteria. This survey can be considered a good basis for the development of further studies focused on monitoring both sanitary and animal pathology, creating a specific network in the environments of interest.

Explaining the barriers faced by veterinarians against preventing antimicrobial resistance: an innovative interdisciplinary qualitative study

BackgroundConsidering the significance of increased antimicrobial resistance (AMR) and its adverse effects on individual and social health and the important and effective role that veterinarians play in controlling this growing issue worldwide, it is essential to have effective preventive control programs. To this aim, the first step is to identify the factors behind the prevalence of AMR in Iran and the barriers veterinarians face to controlling this problem. Thus, the present study was conducted to explain the barriers veterinarians faced in the prevention of AMR from an Iranian veterinarian’s perspective.MethodsThe present research was done in three cities in Iran in 2021. The data were collected through in-depth interviews with 18 veterinarians selected through purposive and snowball sampling and analyzed using conventional qualitative content analysis.ResultsThe data analysis results were classified into 4 main categories and 44 subcategories. The former included: educational factors, administrative/legal factors, client-related factors, and veterinarian-related factors.ConclusionsThe increased AMR can be approached from multiple aspects. Considering the different factors that affect the increased AMR, it is necessary to consider them all through effective planning and policy-making at multi-level and multidisciplinary dimensions. There is special attention needed to scientific and practical interventions at the individual, interpersonal, social, and even political levels. At the same time, measures should be taken to rehabilitate and maintain the health of society to strengthen supervision and attract the full participation of interested organizations.

ESBL-Producing Enterobacterales at the Human–Domestic Animal–Wildlife Interface: A One Health Approach to Antimicrobial Resistance in Piauí, Northeastern Brazil

The use, misuse, and overuse of antimicrobials is one of the main public health threats of the 21st century. We investigated the risk factor of the presence of extended-spectrum, cephalosporin-resistant Enterobacterales in feces of non-domestic and domestic birds and other domestic animals in Piauí State, northeast Brazil. We collected a total of 387 cloacal and rectal swab samples of free-living birds, domestic birds, and domestic mammals in five municipalities: Amarante, Água Branca, Lagoa Alegre, Parnaíba, and Teresina. A total of 59/387 (15.2%) of these samples harbored extended spectrum beta-lactamase (ESBL)-producing Enterobacterales. Using the MALDI-TOF technique, we identified fifty-seven samples as Escherichia coli and two samples as Klebsiella pneumoniae. Teresina and Parnaíba had the highest prevalence of animals with resistant bacteria (32.1% and 27.1%, respectively) and highest exposure risk factor (OR of 16.06 and 8.58, respectively, and p < 0.001 for all). Multidrug-resistant, ESBL-producing Enterobacterales were observed in 72.8% of the samples (43/59). For the free-living birds, the positive samples belonged to a great kiskadee (Pitangus sulphuratus) and a semipalmated sandpiper (Calidris pusilla) in migratory and resident species, respectively. For domestic animals, the swine samples showed the highest prevalence of antimicrobial resistance. The lack of access to veterinary care and information regarding antimicrobial therapy, along with the easy access to antimicrobials without medical prescription, favors the inadequate use of antimicrobials in Piauí.

Prevalence of Infections and Antimicrobial Resistance of ESKAPE Group Bacteria Isolated from Patients Admitted to the Intensive Care Unit of a County Emergency Hospital in Romania

The ESKAPE group (Enterococcus faecium, Staphylococcus aureus, Klebsiella Pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp.) is a group of bacteria very difficult to treat due to their high ability to acquire resistance to antibiotics and are the main cause of nosocomial infections worldwide, posing a threat to global public health. Nosocomial infections with MDR bacteria are found mainly in Intensive Care Units, due to the multitude of maneuvers and invasive medical devices used, the prolonged antibiotic treatments, the serious general condition of these critical patients, and the prolonged duration of hospitalization. Materials and Methods: During a period of one year, from January 2023 to December 2023, this cross-sectional study was conducted on patients diagnosed with sepsis admitted to the Intensive Care Unit of the Sibiu County Emergency Clinical Hospital. Samples taken were tracheal aspirate, catheter tip, pharyngeal exudate, wound secretion, urine culture, blood culture, and peritoneal fluid. Results: The most common bacteria isolated from patients admitted to our Intensive Care Unit was Klebsiella pneumoniae, followed by Acinetobacter baumanii and Pseudomonas aeruginosa. Gram-positive cocci (Enterococcus faecium and Staphilococcus aureus) were rarely isolated. Most of the bacteria isolated were MDR bacteria. Conclusions: The rise of antibiotic and antimicrobial resistance among strains in the nosocomial environment and especially in Intensive Care Units raises serious concerns about limited treatment options.

Long-Term Co-Circulation of Host-Specialist and Host-Generalist Lineages of Group B Streptococcus in Brazilian Dairy Cattle with Heterogeneous Antimicrobial Resistance Profiles

Group B Streptococcus (GBS) is a major cause of contagious bovine mastitis (CBM) in Brazil. The GBS population is composed of host-generalist and host-specialist lineages, which may differ in antimicrobial resistance (AMR) and zoonotic potential, and the surveillance of bovine GBS is crucial to developing effective CBM control and prevention measures. Here, we investigated bovine GBS isolates (n = 156) collected in Brazil between 1987 and 2021 using phenotypic testing and whole-genome sequencing to uncover the molecular epidemiology of bovine GBS. Clonal complex (CC) 61/67 was the predominant clade in the 20th century; however, it was replaced by CC91, with which it shares a most common recent ancestor, in the 21st century, despite the higher prevalence of AMR in CC61/67 than in CC91, and high selection pressure for AMR from indiscriminate antimicrobial use in the Brazilian dairy industry. CC103 also emerged as a dominant CC in the 21st century, and a considerable proportion of herds had two or more GBS strains, suggesting poor biosecurity and within-herd evolution due to the chronic nature of CBM problems. The majority of bovine GBS belonged to serotype Ia or III, which was strongly correlated with CCs. Ninety-three isolates were resistant to tetracycline (≥8 μg/mL; tetO = 57, tetM = 34 or both = 2) and forty-four were resistant to erythromycin (2.0 to >4 μg/mL; ermA = 1, ermB = 38, mechanism unidentified n = 5). Only three isolates were non-susceptible to penicillin (≥8.0 μg/mL), providing opportunities for improved antimicrobial stewardship through the use of narrow-spectrum antimicrobials for the treatment of dairy cattle. The common bovine GBS clades detected in this study have rarely been reported in humans, suggesting limited risk of interspecies transmission of GBS in Brazil. This study provides new data to support improvements to CBM and AMR control, bovine GBS vaccine design, and the management of public health risks posed by bovine GBS in Brazil.

Multimodal nanoimmunotherapy engages neutrophils to eliminate Staphylococcus aureus infections.

The increasing prevalence of antimicrobial resistance in Staphylococcus aureus necessitates alternative therapeutic approaches. Neutrophils play a crucial role in the fight against S. aureus but suffer from deficiencies in function leading to increased infection. Here we report a nanoparticle-mediated immunotherapy aimed at potentiating neutrophils to eliminate S. aureus. The nanoparticles consist of naftifine, haemoglobin (Hb) and a red blood cell membrane coating. Naftifine disrupts staphyloxanthin biosynthesis, Hb reduces bacterial hydrogen sulfide levels and the red blood cell membrane modifies bacterial lipid composition. Collectively, the nanoparticles can sensitize S. aureus to host oxidant killing. Furthermore, in the infectious microenvironment, Hb triggers lipid peroxidation in S. aureus, promoting neutrophil chemotaxis. Oxygen supplied by Hb can also significantly enhance the bactericidal capability of the recruited neutrophils by restoring neutrophil respiratory burst via hypoxia relief. This multimodal nanoimmunotherapy demonstrates excellent therapeutic efficacy in treating antimicrobial-resistant S. aureus persisters, biofilms and S. aureus-induced infection in mice.

Etiology of bacterial pneumonia and multi-drug resistance pattern among pneumonia suspected patients in Ethiopia: a systematic review and meta-analysis

BackgroundBacterial pneumonia can affect all age groups, but people with weakened immune systems, young children, and the elderly are at a higher risk. Streptococcus pneumoniae, Klebsiella pneumoniae, Haemophilus influenzae, and Pseudomonas aeruginosa are the most common causative agents of pneumonia, and they have developed high MDR in recent decades in Ethiopia. This systematic review and meta-analysis aimed to determine the pooled prevalence of bacterial pneumonia and multidrug resistance in Ethiopia.MethodsThe articles were searched extensively in the electronic databases and grey literature using entry terms or phrases. Studies meeting the eligibility criteria were extracted in MS Excel and exported for statistical analysis into STATA version 14 software. The pooled prevalence of bacterial pneumonia and multidrug resistance were calculated using a random-effects model. Heterogeneity was assessed by using the I2 value. Publication bias was assessed using a funnel plot and Egger’s test. A sensitivity analysis was done to assess the impact of a single study on the pooled effect size.ResultOf the 651 studies identified, 87 were eligible for qualitative analysis, of which 11 were included in the meta-analysis consisting of 1154 isolates. The individual studies reported prevalence of bacterial pneumonia ranging from 6.19 to 46.3%. In this systematic review and metanalysis, the pooled prevalence of bacterial pneumonia in Ethiopia was 37.17% (95% CI 25.72–46.62), with substantial heterogeneity (I2 = 98.4%, p < 0.001) across the studies. The pooled prevalence of multidrug resistance in bacteria isolated from patients with pneumonia in Ethiopia was 67.73% (95% CI: 57.05–78.40). The most commonly isolated bacteria was Klebsiella pneumoniae, with pooled prevalence of 21.97% (95% CI 16.11–27.83), followed by Streptococcus pneumoniae, with pooled prevalence of 17.02% (95% CI 9.19–24.86), respectively.ConclusionThe pooled prevalence of bacterial isolates from bacterial pneumonia and their multidrug resistance were high among Ethiopian population. The initial empirical treatment of these patients remains challenging because of the strikingly high prevalence of antimicrobial resistance.

Occurrence of antimicrobial resistance uropathogenic &lt;i&gt;Staphylococcus aureus&lt;/i&gt; isolates from pregnant women attending antenatal clinics within Ilorin

Background: Staphylococus aureus associated with urinary tract infection (UTI) has become a serious health problem especially with the emergence of methicillin resistant Staphylococus aureus (MRSA) due to the acquisition of mecA gene leading to increasing maternal and perinatal burden. This study aimed to evaluate the prevalence of antimicrobial resistance, β-lactamase production and methicillin resistance among uropathogenic S. aureus among pregnant women attending selected antenatal clinics in Ilorin.Methods: Forty-five (45) out of 79 presumptive uropathogenic S. aureus isolated over a period of 12 months from urine samples of pregnant women were identified using standard bacteriological methods. Antibiogram studies was performed using gentamicin (CN-10μg), ciprofloxacin (CIP-5μg), ofloxacin (OFX-5μg), tetracycline (TE-30μg), sulphamethaxozole-trimethoprim (SXT-25μg), ampicillin (AMP-10 μg), penicillin G (P-10 units), nitrofurantoin (F-30 μg) and cefoxitin (FOX-30 μg) for the detection of MRSA by disc diffusion method. Furthermore, detection of β - lactamase producing S. aureus (BL-PSA) was carried out using Iodometric paper strip method.Results: Of the 45 S. aureus isolates, 80% were BL-PSA, MRSA (87%), exhibiting high resistance to penicillin G (97.8%), ampicillin (95.5%), tetracycline (77.8%) and sulphamethaxozole trimethoprim (64.4%). In addition, 56% were multidrug-resistant (MDR) exhibiting 20 different phenotypes with CN-P-SXT-TE-AMP-FOX (15.6%) being the majority. Notwithstanding, S. aureus isolates showed high sensitivity to nitrofurantoin (93.3%) and ofloxacin (91.1%).Conclusion: This study established an increasing resistance of S. aureus to different classes of antibiotics which emphasize the need for constant surveillance to monitor antimicrobial resistance trends. Routine screening for BL-PSA and MRSA among uropathogenic S. aureus is also advocated in order to reduce the development and spread of MDR isolates.

Variation in Pen-Level Prevalence of BRD Bacterial Pathogens and Antimicrobial Resistance Following Feedlot Arrival in Beef Calves.

Antimicrobials are crucial for treating bovine respiratory disease (BRD) in beef feedlots. Evidence is needed to support antimicrobial use (AMU) decisions, particularly in the early part of the feeding period when BRD risk is highest. The study objective was to describe changes in prevalence and antimicrobial susceptibility of BRD bacterial pathogens at feedlot processing (1 day on feed (1DOF)), 12 days later (13DOF), and for a subset at 36DOF following metaphylactic antimicrobial treatment. Mixed-origin steer calves (n = 1599) from Western Canada were managed as 16 pens of 100 calves, receiving either tulathromycin (n = 1199) or oxytetracycline (n = 400) at arrival. Deep nasopharyngeal swabs collected at all time points underwent culture and antimicrobial susceptibility testing (AST). Variability in the pen-level prevalence of bacteria and antimicrobial susceptibility profiles were observed over time, between years, and metaphylaxis options. Susceptibility to most antimicrobials was high, but resistance increased from 1DOF to 13DOF, especially for tetracyclines and macrolides. Simulation results suggested that sampling 20 to 30 calves per pen of 200 reflected the relative pen-level prevalence of the culture and AST outcomes of interest. Pen-level assessment of antimicrobial resistance early in the feeding period can inform the evaluation of AMU protocols and surveillance efforts and support antimicrobial stewardship in animal agriculture.

Understanding antibiotic use in the community setting in Thailand: Does communication matter?

It is known that the misuse and overuse of antimicrobials leads to antimicrobial resistance (AMR). Effective communication between dispensers and users is thus crucial in reducing inappropriate antibiotic use. This study aims to gain a better understanding of communication around the use of antibiotics in the community and seeks potential implementation strategies to change dispenser and user practices in communication aspects. Qualitative methods were employed, including in-depth interviews with 18 drug suppliers and 16 community members, and eight focus group discussions with key informants. Data were collected in the Kanchanaburi Demographic Health Surveillance System in urban and semi-urban communities in the western region of Thailand. The thematic analysis included communication quality, communication and imbalanced power, and misconceptions and instruction. The OpenCode qualitative software program was employed. The study revealed that the quality of communication was significantly influenced by the interaction of antibiotic dispensing with language and information. This interaction creates communication constraints between those dispensing antibiotics and the recipients, resulting in a less-than-optimal exchange of information. Consequently, users received limited information concerning the proper use of antibiotics. Furthermore, power imbalances and communication dynamics were perpetuated, mainly stemming from varying levels of access to and knowledge about antibiotics. This imbalance in power dynamics became evident between those dispensing antibiotics and the users. Users, as well as dispensers lacking proper qualifications, found themselves in a precarious position due to their inadequate knowledge of antibiotics. Moreover, it is noteworthy that misconceptions often conflicted with antibiotic instructions, leading to challenges in adhering to antibiotic regimens. These challenges primarily arose from misconceptions about antibiotics and concerns about potential side effects, particularly when users started to feel better. The findings highlight the importance of enhancing communication between dispensers and users through future interventions. These interventions should aim to bolster user understanding of antibiotics and provide clear, trustworthy instructions for their proper usage. Investigating innovative communication methods, such as the use of QR codes, presents a promising avenue for consideration. By addressing these communication gaps, we can advocate for the appropriate utilization of antibiotics and mitigate the prevalence of AMR.

Antiviral Drug Candidate Repositioning for Streptococcus suis Infection in Non-Tumorigenic Cell Models.

The increasing prevalence of antimicrobial resistance against zoonotic bacteria, including Streptococcus (S.) suis, highlights the need for new therapeutical strategies, including the repositioning of drugs. In this study, susceptibilities of bacterial isolates were tested toward ten different 3-amidinophenyalanine (Phe(3-Am)) derivatives via determination of minimum inhibitory concentration (MIC) values. Some of these protease inhibitors, like compounds MI-432, MI-471, and MI-476, showed excellent antibacterial effects against S. suis. Their drug interaction potential was investigated using human liver microsomal cytochrome P450 (CYP450) measurements. In our work, non-tumorigenic IPEC-J2 cells and primary porcine hepatocytes were infected with S. suis, and the putative beneficial impact of these inhibitors was investigated on cell viability (Neutral red assay), on interleukin (IL)-6 levels (ELISA technique), and on redox balance (Amplex red method). The antibacterial inhibitors prevented S. suis-induced cell death (except MI-432) and decreased proinflammatory IL-6 levels. It was also found that MI-432 and MI-476 had antioxidant effects in an intestinal cell model upon S. suis infection. Concentration-dependent suppression of CYP3A4 function was found via application of all three inhibitors. In conclusion, our study suggests that the potential antiviral Phe(3-Am) derivatives with 2',4' dichloro-biphenyl moieties can be considered as effective drug candidates against S. suis infection due to their antibacterial effects.

Prevalence of antimicrobial resistance, biofilm formation, efflux pump activity, and virulence capabilities in multi-drug-resistant Klebsiella pneumoniae isolated from freshwater fish farms.

The present study aimed to determine the antibiotic resistance, underlying mechanisms, antibiotic residues, and virulence genes involved in 32 multi-drug-resistant Klebsiella pneumoniae isolates from freshwater fishes in Andhra Pradesh, India. Antibiogram studies revealed that all isolates were multi-drug-resistant, harbored tetA (96.8%), tetC (59.3%), tetD (71.9%), nfsA (59.3%), nfsB (53.1%), sul2 (68.7%), qnrC (43.7%), qnrD (50%), blaSHV (75%), blaTEM (68.7%), and blaCTX-M (93.7%) genes. Multiple antibiotic resistance index was calculated as 0.54. Sixteen isolates were confirmed to be hyper-virulent and harbored magA and rmpA genes. In total, 46.9, 31.2, and 21.9% of the isolates were categorized as strong, moderate, or weak biofilm formers, respectively. All isolates possessed an active efflux pump and harbored acrA, acrB, acrAB, and tolC genes in 94% of the isolates, followed by mdtK (56.2%). Porins such as ompK35 and ompK36 were detected in 59.3 and 62.5% of the isolates, respectively. Virulence genes fimH-1, mrkD, and entB were present in 84.3, 81.2, 87.5% of the isolates, respectively. These findings imply a potential threat that multi-drug-resistant bacterial pathogens could transmit to surrounding environments and humans through contaminated water and the aquaculture food chain.

Bacteriophages as a potential substitute for antibiotics: A comprehensive review.

Over the years, the administration of antibiotics for the purpose of addressing bacterial infections has become increasingly challenging due to the increased prevalence of antimicrobial resistance exhibited by various strains of bacteria. Multidrug-resistant(MDR) bacterial species are rising due to the unavailability of novel antibiotics, leading to higher mortality rates. With these conditions, there is a need for alternatives in which phage therapy has made promising results. Phage-derived endolysins, phage cocktails, and bioengineered phages are effective and have antimicrobial properties against MDRand extensively drug-resistant strains. Despite these, it has been observed that phages can give antimicrobial activity to more than one bacterial species. Thus, phage cocktail against resistant strains provides broad spectrum treatment and magnitude of effectivity, which is many folds higher than antibiotics. Many commercially available endolysins such as Staphefekt SA.100, Exebacase (CF-301), and N-Rephasin®SAL200 are used in biofilm penetration and treating plant diseases. The role of CMP1 phage endolysin in transgenic tomato plants in preventing Clavibacter michiganensis infection and the effectiveness of phage in protecting Atlantic salmon from vibriosis have been reported. Furthermore, phage-derived endolysin therapy, such as TSPphg phage exogenous treatment, can aid in disrupting cell walls, leading to bacterial cell lysis. As animals in aquaculture and slaughterhouses are highly susceptible to bacterial infections, effective phage therapy instead of antibiotics can help treat poultry animals, preserve them, and facilitate disease-free trade. Using bioengineered phages and phage cocktails enhances the effectiveness by providing a broad spectrum of phages and target specificity. Research is currently being conducted on clinical trials to confirm the efficacy of engineered phages and phage cocktails in humans. Although obtaining commercial approval may be time-consuming, it will be beneficial in the postantibiotic era. This review provides an overview of the significance of phage therapy as a potential alternative to antibiotics in combating resistant bacterial strains and its application to various fields and emphasizes the importance of safeguarding and ensuring treatment efficacy.

Antimicrobial Properties of Pliek U as Traditional Acehnese Fermented Spices

The high prevalence of antimicrobial resistance globally has increased the burden of disease. The phenomenon demands urgency to explore new antimicrobial drugs, one of which is sourced from natural ingredient, spices. Pliek U, as one of the spices traditionally processed by Acehnese, has attracted researchers to explore its potential source for antimicrobial substances. The objective of this literature review is to explore the characteristic, production, chemical composition, and antimicrobial mechanism of Pliek U. A literature search was carried out on PubMed, Science Direct, Springer Link, and Google Scholar using the keywords "Pliek U”, “Coconut Flesh”, and “Antimicrobial”. The articles obtained were then screened based on predetermined criteria. The results of the analysis were displayed in tabular and narrative form. The final result was 8 main articles and 10 additional articles after screening 65 articles obtained from the database. Pliek U powder is traditionally produced and has unique characteristics that make it easy to recognize. Pliek U mechanism of action based on the chemical composition and the role of lactic acid bacteria in the fermentation process. Analysis shows that Pliek U is a promising antimicrobial source, so it needs to be researched and developed further in the pre-clinical to clinical phases.

Changing dynamics of antibiotic resistant Escherichia in Caspian gulls shows the importance of longitudinal environmental studies

This study is focused on Escherichia spp. isolates resistant to critically important antibiotics (cefotaxime, ciprofloxacin and colistin) among Caspian gull’s (Larus cachinnans) chicks nesting in the Nove Mlyny Water Reservoir, Czech Republic. The prevalence of antimicrobial resistance (AMR) in bacteria within wild birds is commonly evaluated using a single sampling event, capturing only a brief and momentary snapshot at a particular location. Therefore, the Caspian gulls in our study were sampled in May 2018 (n = 72) and May 2019 (n = 45), and a water sample was taken from the reservoir (2019). We obtained 197 isolates identified as E. coli by MALDI-TOF MS. A total of 158 representative isolates were whole-genome sequenced, 17 isolates were then reclassified to Escherichia albertii. We observed a higher (86 %; 62/72) occurrence of ESBL/AmpC-producing Escherichia spp. among gulls in 2018 compared to 38 % (17/45) in 2019 (p < 0.00001). The decrease in prevalence was linked to clonal lineage of E. coli ST11893 predominating in 2018 which carried blaCMY-2 and which was not recovered from the gulls in 2019. Oppositely, several Escherichia STs were found in gulls from both years as well as in the water sample including STs commonly recognized as internationally high-risk lineages such as ST10, ST58, ST88, ST117, ST648 or ST744. Phylogenetic analysis of E. coli from EnteroBase from countries where these particular gulls wander revealed that some STs are commonly found in various sources including humans and a portion of them is even closely related (up to 100 SNPs) to our isolates. We demonstrated that the occurrence of AMR in Escherichia can vary greatly in time in synanthropic birds and we detected both, a temporary prevalent lineage and several persistent STs. The close relatedness of isolates from gulls and isolates from EnteroBase highlights the need to further evaluate the risk connected to wandering birds.

Review of quorum-quenching probiotics: A promising non-antibiotic-based strategy for sustainable aquaculture.

The emergence of antibiotic-resistant bacteria (ARBs) and genes (ARGs) in aquaculture underscores the urgent need for alternative veterinary strategies to combat antimicrobial resistance (AMR). These measures are vital to reduce the likelihood of entering a post-antibiotic era. Identifying environmentally friendly biotechnological solutions to prevent and treat bacterial diseases is crucial for the sustainability of aquaculture and for minimizing the use of antimicrobials, especially antibiotics. The development of probiotics with quorum-quenching (QQ) capabilities presents a promising non-antibiotic strategy for sustainable aquaculture. Recent research has demonstrated the effectiveness of QQ probiotics (QQPs) against a range of significant fish pathogens in aquaculture. QQ disrupts microbial communication (quorum sensing, QS) by inhibiting the production, replication, and detection of signalling molecules, thereby reducing bacterial virulence factors. With their targeted anti-virulence approach, QQPs have substantial promise as a potential alternative to antibiotics. The application of QQPs in aquaculture, however, is still in its early stages and requires additional research. Key challenges include determining the optimal dosage and treatment regimens, understanding the long-term effects, and integrating QQPs with other disease control methods in diverse aquaculture systems. This review scrutinizes the current literature on antibiotic usage, AMR prevalence in aquaculture, QQ mechanisms and the application of QQPs as a sustainable alternative to antibiotics.

Antimicrobial Susceptibility Profiles of Bacteria Isolated from Traditionally Fermented Bovine Milk from Selected Farms of Kajiado- Central Sub-County, Kenya

Introduction: Fermented bovine milk provides a conducive environment for the growth of bacteria some of which could be of zoonotic importance. These bacteria can develop antimicrobial resistance (AMR) due to the regular use of antibiotics in animals. Materials and methods: This cross-sectional study was undertaken to determine the antibiotic sensitivity of bacteria isolated from traditionally fermented milk obtained and processed from 114 indigenous cows kept by Maasai pastoralists in Kajiado County, Kenya. The Kirby-Bauer Disk diffusion method was used to determine the antimicrobial susceptibility profiles of the isolated Staphylococcus spp., Escherichia coli, Klebsiella spp., and Salmonella typhi. Results: The susceptibility of the isolated bacteria was determined using nine antibiotics namely chloramphenicol (10μg), kanamycin (30μg), penicillin G (10μg), streptomycin (10μg), oxytetracycline (30μ) tetracycline (30μg), vancomycin (30μg), gentamycin (10μg) and Ampicillin (10μg). The Staphylococcus (S.) aureus isolates exhibited diverse resistance patterns to the antibiotics with the greatest resistance observed against oxytetracycline (69.2%), streptomycin (69.2%), and kanamycin (61.5%). However, a significant proportion of the S. aureus strains demonstrated a 100% susceptibility rate to gentamycin and vancomycin. Escherichia coli isolates exhibited resistance to vancomycin (100%), tetracycline (80%), oxytetracycline (80 %), and ampicillin (60 %) and were highly (100%) sensitive to the other antibiotics. Salmonella typhi isolates were resistant to vancomycin (88.8%) and highly (100%) sensitive to chloramphenicol, penicillin G, gentamycin, and streptomycin. Klebsiella spp. were highly resistant to vancomycin (100%) and were sensitive to gentamycin (100%) and streptomycin (100%). Conclusion: The study showed a high prevalence of AMR in bacteria isolated from traditional milk consumed by the pastoralists and thus there is a high risk of zoonotic spread of the pathogenic bacteria. There is a need to educate the local households on strategies to minimize the occurrence of AMR in animals and also improve hygiene practices in the preparation of traditionally fermented milk.       

Antimicrobial resistance landscape in a metropolitan city context using open drain wastewater-based metagenomic analysis

One Health concept recognizes the inextricable interactions of diverse ecosystems and their subsequent effect on human, animal and plant health. Antimicrobial resistance (AMR) is a major One Health concern and is predicted to cause catastrophes if appropriate measures are not implemented. To understand the AMR landscape in a south Indian metropolitan city, metagenomic analysis of open drains was performed. The data suggests that in January 2022, macrolide class of antibiotics contributed the highest resistance of 40.1% in the city, followed by aminoglycoside- 24.4%, tetracycline- 11.3% and lincosamide- 6.7%. The ‘mutations in the 23S rRNA gene conferring resistance to macrolide antibiotics’ were the major contributor of resistance with a prevalence of 39.7%, followed by ‘16s rRNA with mutation conferring resistance to aminoglycoside antibiotics’- 22.2%, ‘16S rRNA with mutation conferring resistance to tetracycline derivatives’- 9.2%, and ‘23S rRNA with mutation conferring resistance to lincosamide antibiotics’- 6.7%. The most prevalent antimicrobial resistance gene (ARG) ‘mutations in the 23S rRNA gene conferring resistance to macrolide antibiotics’ was present in multiple pathogens including Escherichia coli, Campylobacter jejuni, Acinetobacter baumannii, Streptococcus pneumoniae, Pseudomonas aeruginosa, Neisseria gonorrhoeae, Klebsiella pneumoniae and Helicobacter pylori. Most of the geographical locations in the city showed a similar landscape for AMR. Considering human mobility and anthropogenic activities, such an AMR landscape could be common across other regions too. The data indicates that pathogens are evolving and acquiring antibiotic resistance genes to evade antibiotics of multiple major drug classes in diverse hosts. The outcomes of the study are relevant not only in understanding the resistance landscape at a broader level but are also important for identifying the resistant drug classes, the mechanisms of gaining resistance and for developing new drugs that target specific pathways. This kind of surveillance protocol can be extended to regions in other developing countries to assess and combat the problem of antimicrobial resistance.

Assessment of freshwater fish farms for the identification of the geographical areas harbouring antimicrobial resistance

Assessment of antimicrobial resistance (AMR) in freshwater fish farms has been rarely investigated. Aeromonas are considered as an indicator organism for monitoring AMR in aquatic environment. Identification of the geographical areas harbouring AMR have implications for developing AMR mitigation strategies. The present study investigated the prevalence of AMR in freshwater fish farms (n = 124) in four districts (A-D) of Uttar Pradesh, India. The study revealed significantly higher AMR in fish farms of district D for ceftazidime, cefotaxime and trimethoprim-sulfamethoxazole. Similarly, AMR to ciprofloxacin and tetracycline was significantly higher in district A, and cefoxitin (FOX) in district B. District D also showed the highest number of MDR strains, AmpC and ESBL producers. Overall, maximum AMR was seen to β-lactams (35.5%) and aminoglycosides (14.5%). Twenty-five AMR phenotypes and eighteen AMR genotypes were detected in the study. The farms of district D showed significantly higher number of resistant phenotypes (≥3 antimicrobials). Furthermore, the study identified the species of Aeromonas contributing to AMR. Two clusters were observed: cluster I- resistant to FOX only, and cluster II (comprising of A. caviae and A. veronii bv veronii)- resistant to multiple antimicrobials and included majority of AmpC producers. A. caviae had significantly higher MAR than other Aeromonas species. The ARGs shared among the cluster II species and its close relative A. veronii bv sobria were blaTEM,sul1, tet(E) and blaCIT. Overall, our study identified the geographical districts harbouring higher AMR in the freshwater fish farms. These findings suggest the need for spatial assessment of AMR in aquaculture.