Spread Of Antibiotic Resistance Research Articles

Occurrence of Antibiotic Resistance in Lotic Ecosystems

Antibiotic resistance is a matter of global public health concern. Antibiotic resistance isdisseminated by antibiotic resistance genes (ARGs) which are carried by antibiotic resistancebacteria (ARBs). Lotic ecosystems like rivers which has flowing water can spread ARGs fromone location to another. Such dispersion of ARGs can also move through food chains and foodwebs making the spread of antibiotic resistance more complex and widespread. Detection ofthese ARGs is important for understanding the origin and pathways of antibiotic resistancein our waterways. Both culturing and non-culturing methods can be used for detection ofthese ARGs. Overall, understanding the sources, assessing the presence, and determining thedissemination of antibiotic resistance is important for us to understand the level of antibioticpollution in our waterbodies.

An optimized antimicrobial peptide analog acts as an antibiotic adjuvant to reverse methicillin-resistant Staphylococcus aureus

The misuse of antibiotics in animal protein production has driven the emergence of a range of drug-resistant pathogens, which threaten existing public health security. Consequently, there is an urgent need to develop novel antimicrobials and new infection treatment options to address the challenges posed by the dramatic spread of antibiotic resistance. Piscidins, a class of fish-specific antimicrobial peptides (AMPs), are regarded as promising therapies for biomedical applications. Progress towards potential analogs from the piscidin family has been hampered by unenforceable structural optimization strategies. Here, we leverage a strategy of bioinformatics analysis combined with molecular dynamics (MD) simulation to identify specific functional hotspots in piscidins and rationally design related analogues. As expected, this approach yields a potent and non-toxic PIS-A-1 that can be used as an antibiotic adjuvant to reverse methicillin-resistant Staphylococcus aureus (MRSA) pathogens. Remarkably, the structural optimization scheme and application strategy proposed here will contribute richer therapeutic options for the safe production of animal protein.

Awareness regarding antimicrobial resistance and confidence to prescribe antibiotics in dentistry: a cross-continental student survey

BackgroundThe antimicrobial resistance (AMR) crisis is a major global threat and one of its biggest drivers is the overuse of antibiotics in humans. Dentists are responsible for 5–10% antibiotic prescriptions worldwide and recent data suggest that knowledge and prescribing practices need improvement.MethodsA cross-sectional web-survey was sent to dental students from six universities in Norway, Canada, and Brazil. Topics addressed covered awareness, confidence to prescribe antibiotics, and education needs. Data were presented descriptively and statistical testing was employed to compare group means when applicable.ResultsIn total, 562 responses were collected across the three countries with a response rate of 28.6%. ‘Antibiotic resistance’ was among the highest priorities (scale 1–10) with an average of 8.86 (SEM ± 0.05), together with ‘Gender inequality’ (8.68 ± 0.07) and ‘Climate change’ (8.68 ± 0.07). Only 28.8% thought that Dentistry was engaged in national/international campaigns promoting awareness on the topic and 8.9% stated to have heard about the ‘One Health’ concept. Final year dental students showed an average confidence to prescribe antibiotics of 7.59 (± 0.14). Most students demonstrated interest in receiving additional education on all topics listed, with the three most pressing being ‘antibiotic prescription for treatment of infections’ (82.9%), ‘drug interactions’ (80.9%), and ‘spread of antibiotic resistance’ (79.6%). A trend was observed between higher awareness regarding the topic and higher confidence to prescribe.ConclusionsThere is a need to revisit dental education on antibiotic resistance with a global perspective and to create more stewardship initiatives that promote awareness on the topic.

Antimicrobial and Antibiofilm Effect of 4,4'-Dihydroxy-azobenzene against Clinically Resistant Staphylococci.

The spread of antibiotic resistance among human and animal pathogens is one of the more significant public health concerns. Moreover, the restrictions on the use of particular antibiotics can limit the options for the treatment of infections in veterinary clinical practice. In this context, searching for alternative antimicrobial substances is crucial nowadays. In this study, 4,4'-dihydroxy-azobenzene (DHAB) was tested for its potential in vitro as an antimicrobial agent against two relevant human and animal pathogens, namely Staphylococcus aureus and Staphylococcus pseudintermedius. The values of minimal inhibitory concentration (MIC) were 64 and 32 mg/L respectively, and they comparable to other azo compounds of probed antimicrobial activity. In addition, the minimal bactericidal concentrations (MCB) were 256 and 64 mg/L. The mechanism by which DHAB produces toxicity in staphylococci has been investigated. DHAB caused membrane damage as revealed by the increase in thiobarbituric acid reactive substances (TBARS) such as malondialdehyde. Furthermore, differential induction of the enzymes peroxidases and superoxide dismutase in S. aureus and S. pseudintermedius suggested their prevalent role in ROS-scavenging due to the oxidative burst induced by this compound in either species. In addition, this substance was able to inhibit the formation of biofilms by both bacteria as observed by colorimetric tests and scanning electron microscopy. In order to assess the relevance of DHAB against clinical strains of MRSA, 10 clinical isolates resistant to either methicillin or daptomycin were assayed; 80% of them gave values of CMI and CMB similar to those of the control S. aureus strain. Finally, cutaneous plasters containing a composite formed by an agar base supplemented with DHAB were designed. These plasters were able to inhibit in vitro the growth of S. aureus and S. pseudintermedius, particularly the later, and this suggests that this substance could be a promising candidate as an alternative to antibiotics in the treatment of animal skin infections, as it has been proven that the toxicity of this substance is very low particularly at a dermal level.

Piper nigrum Fruit Extract as an Antibiotic Resistance Reversal Agent in MDR Bacteria

Antibiotic resistance development and spread in clinical pathogens is an immense threat that has already outpaced the discovery and development of novel and more effective antibiotic drugs. Recently the focus has been shifted to medicinal plants as novel therapeutic options for reversing antibiotic resistance by targeting different resistance mechanisms. Piper nigrum is a plant that has the potential to reverse antibiotic resistance and increase the efficacy of the current drugs. In the present study, seven different antibiotics, clindamycin, gentamicin, levofloxacin, amikacin, tigecycline, imipenem, and tetracycline, were used against antibiotic-resistant Staphylococcus aureus and Salmonella typhi. Antibiotic resistance reversal analysis was tested by the AST disc method. Increased zones of inhibition of S. aureus by four antibiotics, clindamycin (9 mm), gentamicin (7 mm), levofloxacin (9 mm), and amikacin (9 mm) were recorded after using P. nigrum extract. In addition, the use of P. nigrum extract also increased the zone of inhibition of S. typhi with amikacin (11 mm), gentamicin (10 mm), tigecycline (9 mm), levofloxacin (11 mm), and imipenem (10 mm). This study suggests that P. nigrum extracts can be used as natural antibiotic resistance reversal agents that increase the effectiveness of current antibiotics and can reverse antibiotic resistance.

Prevalence of macrolide-lincosamide-streptogramin resistant lactic acid bacteria isolated from food samples.

Lactic acid bacteria (LAB) being a reservoir of antibiotic resistance genes, tend to disseminate antibiotic resistance that possibly pose a threat to human and animal health. Therefore, the study focuses on the prevalence of macrolide-lincosamide-streptogramin- (MLS) resistance among LAB isolated from various food samples. Diverse phenotypic and genotypic MLS resistance were determined among the LAB species (n = 146) isolated from fermented food products (n = 6) and intestine of food-producing animals (n = 4). Double disc, triple disc diffusion and standard minimum inhibitory concentration (MIC) tests were evaluated for phenotypic MLS resistance. Specific primers for MLS resistance genes were used for the evaluation of genotypic MLS resistance and gene expressions using total RNA of each isolate at different antibiotic concentrations. The isolates identified are Levilactobacillus brevis (n = 1), Enterococcus hirae (n = 1), Limosilactobacillus fermentum (n = 2), Pediococcus acidilactici (n = 3), Enterococcus faecalis (n = 1). The MIC tests along with induction studies displayed cMLSb, L phenotype, M phenotype, KH phenotype, I phenotype resistance among MLS antibiotics. Genotypic evaluation tests revealed the presence of ermB, mefA/E, msrA/B and msrC genes. Also, gene expression studies displayed increased level of gene expression to the twofold increased antibiotic concentrations. In the view of global health concern, this study identified that food samples and food-producing animals represent source of antibiotic resistant LAB that can disseminate resistance through food chain. This suggests the implementation of awareness in the use of antibiotics as growth promoters and judicious use of antibiotics in veterinary sectors in order to prevent the spread of antibiotic resistance.

Potential Applications of Cannabis Plant Extracts and Phytochemicals as Natural Antimicrobials

Cannabis has been used to treat human diseases for millennia. However, scientific research on its properties has been relatively recent. The spread of antibiotic resistance among human and animal pathogens has stimulated a renewed search for alternative antimicrobial therapies from this and other plant sources. It is further possible that Cannabis extracts or purified cannabinoids could find their way into novel medical applications. Industrial hemp extracts could also be potentially used in food manufacturing (for example, to control biofilms or food packaging), for veterinary purposes, or for microbial control in cleaners and sanitizers. This review highlights the latest findings of Cannabis plant extracts and phytochemicals as new classes of potent antimicrobial agents and their mode of action against different microorganisms, including Gram-positive and Gram-negative bacteria. More importantly, the challenges of using cannabinoids as effective and affordable natural antimicrobial agents are reviewed. While antimicrobial and other applications of Cannabis extracts and phytochemicals (in general) look promising, there are also limitations, particularly around their possible toxic side effects. Accordingly, future research directions are proposed in this report. More research is needed to address the safety of these compounds, determine their activity in vivo, and define structural changes that influence their pharmacokinetic properties. Importantly, standardized tests will be essential to enable valid inter-laboratory comparisons. Future directions in research for developing novel broad-spectrum antibiotics based on Cannabis are discussed in this review article.

Bacterial Dehydrogenases Facilitate Oxidative Inactivation and Bioremediation of Chloramphenicol.

Antimicrobial resistance represents a major threat to human health and knowledge of the underlying mechanisms is therefore vital. Here, we report the discovery and characterization of oxidoreductases that inactivate the broad-spectrum antibiotic chloramphenicol via dual oxidation of the C3-hydroxyl group. Accordingly, chloramphenicol oxidation either depends on standalone glucose-methanol-choline (GMC)-type flavoenzymes, or on additional aldehyde dehydrogenases that boost overall turnover. These enzymes also enable the inactivation of the chloramphenicol analogues thiamphenicol and azidamfenicol, but not of the C3-fluorinated florfenicol. Notably, distinct isofunctional enzymes can be found in Gram-positive (e. g., Streptomyces sp.) and Gram-negative (e. g., Sphingobium sp.) bacteria, which presumably evolved their selectivity for chloramphenicol independently based on phylogenetic analyses. Mechanistic and structural studies provide further insights into the catalytic mechanisms of these biotechnologically interesting enzymes, which, in sum, are both a curse and a blessing by contributing to the spread of antibiotic resistance as well as to the bioremediation of chloramphenicol.

Metagenomic-based surveillance systems for antibiotic resistance in non-clinical settings.

The success of antibiotics as a therapeutic agent has led to their ineffectiveness. The continuous use and misuse in clinical and non-clinical areas have led to the emergence and spread of antibiotic-resistant bacteria and its genetic determinants. This is a multi-dimensional problem that has now become a global health crisis. Antibiotic resistance research has primarily focused on the clinical healthcare sectors while overlooking the non-clinical sectors. The increasing antibiotic usage in the environment - including animals, plants, soil, and water - are drivers of antibiotic resistance and function as a transmission route for antibiotic resistant pathogens and is a source for resistance genes. These natural compartments are interconnected with each other and humans, allowing the spread of antibiotic resistance via horizontal gene transfer between commensal and pathogenic bacteria. Identifying and understanding genetic exchange within and between natural compartments can provide insight into the transmission, dissemination, and emergence mechanisms. The development of high-throughput DNA sequencing technologies has made antibiotic resistance research more accessible and feasible. In particular, the combination of metagenomics and powerful bioinformatic tools and platforms have facilitated the identification of microbial communities and has allowed access to genomic data by bypassing the need for isolating and culturing microorganisms. This review aimed to reflect on the different sequencing techniques, metagenomic approaches, and bioinformatics tools and pipelines with their respective advantages and limitations for antibiotic resistance research. These approaches can provide insight into resistance mechanisms, the microbial population, emerging pathogens, resistance genes, and their dissemination. This information can influence policies, develop preventative measures and alleviate the burden caused by antibiotic resistance.

Protists, Unexpected Players in Waterborne Antibiotic Resistance?

The emergence and spread of antibiotic resistance in aquatic environment such as rivers, lakes, and sewage have accelerated microbial threats to human health by promoting the growth of specific waterborne pathogens and transferring them from the ecosystems to humans. Identifying the unexpected drivers of and bottlenecks for human risk assessment of waterborne antibiotic resistance are crucial in understanding and managing the global ARGs transfer. We showed our current understanding of the factors, residual pollutants, bacteriophages, bacterial communities, and the unexpected players’ protists in driving emergence and transfer of waterborne antibiotic resistance. Heterotrophic protists mainly induce waterborne antibiotic resistance because they can accelerate the transfer of ARGs between bacteria and provide optimal environments for antibiotic-resistant pathogens. Current research, however, still cannot provide a comprehensive understanding of the molecular mechanisms of the impacts of protists on waterborne antibiotic resistance. We have, therefore, summarized the key information that is currently missing and discussed the assessment of resistance risk on human health and finally provided some management strategies.Graphical Abstract

Antibiotics: Precious Goods in Changing Times.

Antibiotics represent a first line of defense of diverse microorganisms, which produce and use antibiotics to counteract natural enemies or competitors for nutritional resources in their nearby environment. For antimicrobial activity, nature has invented a great variety of antibiotic modes of action that involve the perturbation of essential bacterial structures or biosynthesis pathways of macromolecules such as the bacterial cell wall, DNA, RNA, or proteins, thereby threatening the specific microbial lifestyle and eventually even survival. However, along with highly inventive modes of antibiotic action, nature also developed a comparable set of resistance mechanisms that help the bacteria to circumvent antibiotic action. Microorganisms have evolved specific adaptive responses that allow to appropriately react to the presence of antimicrobial agents, thereby ensuring survival during antimicrobial stress. In times of rapid development and spread of antibiotic(multi-)resistance, new resistance-breaking strategies to counteract bacterial infections are desperately needed. This chapter is an update to Chapter 1 of the first edition of this book and intends to give an overview of common antibiotics and their target pathways. It will also present examples for new antibiotics with novel modes of action, illustrating that nature's repertoire of innovative new antimicrobial agents has not been fully exploited yet, and we still might find new drugs that help to evade established antimicrobial resistance strategies.

Fungal hyphae regulate bacterial diversity and plasmid-mediated functional novelty during range expansion

The amount of bacterial diversity present on many surfaces is enormous; however, how these levels of diversity persist in the face of the purifying processes that occur as bacterial communities expand across space (referred to here as range expansion) remains enigmatic. We shed light on this apparent paradox by providing mechanistic evidence for a strong role of fungal hyphae-mediated dispersal on regulating bacterial diversity during range expansion. Using pairs of fluorescently labeled bacterial strains and a hyphae-forming fungal strain that expand together across a nutrient-amended surface, we show that a hyphal network increases the spatial intermixing and extent of range expansion of the bacterial strains. This is true regardless of the type of interaction (competition or resource cross-feeding) imposed between the bacterial strains. We further show that the underlying cause is that flagellar motility drives bacterial dispersal along the hyphal network, which counteracts the purifying effects of ecological drift at the expansion frontier. We finally demonstrate that hyphae-mediated spatial intermixing increases the conjugation-mediated spread of plasmid-encoded antibiotic resistance. In conclusion, fungal hyphae are important regulators of bacterial diversity and promote plasmid-mediated functional novelty during range expansion in an interaction-independent manner.

Antibiotic Resistance: An upcoming Pandemic

Antibiotics are medications that are used to both prevent and treat bacterial infections. Antibiotic resistance arises when bacteria adapt to the usage of antibiotics. Antibiotic resistance develops in bacteria rather than in humans or other animals. These germs can infect both humans and animals, and their infections are more difficult to treat than those caused by non-resistant bacteria. Antibiotic resistance causes greater mortality, longer hospital stays, and higher medical expenses. Our capacity to cure widespread infectious illnesses is being threatened by the emergence and worldwide dissemination of new resistance mechanisms. As antibiotics lose their potency, an increasing range of ailments, such as gonorrhoea, blood poisoning, pneumonia, and tuberculosis (TB), become difficult to treat and, in some cases, incurable. In every region of the globe, antibiotic resistance is increasing to dangerously high levels. It poses a serious danger to public health on a global scale, killing at least 1.27 million people and contributing to approximately 5 million deaths in 2019 [1]. More than 4.6 billion dollars a year is the projected cost to treat infections brought on by six multidrug-resistant pathogens that are often seen in healthcare settings. Escherichia coli is the pathogen that is most commonly reported in Pakistan (68.8% in 2018) [2, 3].
 Antibiotic resistance jeopardizes advances in contemporary medicine. The main issues and concerns in Pakistan are a large number of surplus registered drugs (approximately 50,000), self-medication by more than 50% of the population, and a substantial number of quacks in the country. On average, each patient is given more than three drugs, and antibiotics are given to 70% of patients which is the highest number of prescriptions as compared to rest of the world. General practitioners (GPs) and public hospitals, which favor expensive broad-spectrum antibiotics, are more prone to prescribe these medications impulsively and without consideration [3]. Antibiotic abuse and misuse, as well as inefficient infection prevention and control, all contribute to the rapid spread of antibiotic resistance. Actions can be taken at all societal levels to mitigate the consequences and prevent resistance. Antibiotics should only be used as advised by a licensed healthcare provider. Doctors should only prescribe and give antibiotics when absolutely required, according to current recommendations. To address antibiotic resistance, the government must implement a comprehensive national action plan.

Self-medication with antibiotics and awareness of antibiotic resistance among population in Arar city, Saudi Arabia.

Self-medication with pharmaceutical products can be defined as the use of these products without a medical prescription, and the production, distribution, and sale of these products are the client's responsibility, while they think it is within rational usage. Among these products, antibiotics remain the most serious problem leading to the spread of antibiotic resistance, with consequences of increased morbidity, mortality, and extended hospital stays. This is a cross-sectional study aimed to estimate the prevalence of self-medication with antibiotics among Arar city population and assessing their awareness of antibiotic resistance. Data had been collected through a self-administered validated online questionnaire. Data entry and analysis were performed using a statistical package for the social science program (SPSS) version 20. The overall number of respondents to our survey was 462, with 56.7% female and 43.3% male participants. The prevalence of self-medication with antibiotics was (77.5%). The main reasons for self-medication with antibiotics were ease of use (54.6%) and cost-saving (24.8%). When asked about what they think about self-medication with antibiotics for self-care, 20.1% of our participants thought that it is a good practice and 41.6% thought that it is an acceptable practice. 81.4 % of respondents thought that antibiotic resistance occurs when your body becomes resistant to antibiotics and no longer works well. In the Northern region, despite the open and rapid access to medical care services, it appears that a high proportion of young adult population prefers custom antibiotics without a medical prescription.

SENSITIVITY OF GRAM-NEGATIVE CAUSATIVE AGENTS OF INFECTIOUS INFLAMMATORY DISEASES OF SOFT TISSUES OF THE FACIAL REGION TO ANTIBIOTICS

Today timely monitoring of the sensitivity of gram-negative non-fermenting bacteria taken from various sites of the human body to antibiotics is extremely important in the way of stopping and overcoming significant spread of antibiotic resistance. The aim of this study is to determine the sensitivity of gram-negative causative agents of infectious inflammatory diseases of soft tissues of the face region to antibiotics. Materials and methods. The study included 25 clinical isolates of the genus Acinetobacter and 22 clinical isolates of the genus Pseudomonas. Determination of the sensitivity of microorganisms was carried out using the disc diffusion method and the method of double serial dilutions in a liquid nutrient medium in accordance with the recommendations by EUCAST. Results. The level of sensitivity of representatives of genus Acinetobacter to imipenem and meropenem did not exceed 29.6%. The lowest sensitivity was found to fluoroquinolones and the highest sensitivity was revealed to aminoglycosides. Pseudomonas spp. showed low sensitivity to penicillins and cephalosporins. The similarity of the sensitivity results of Pseudomonas spp. to carbapenems imipenem and meropenem was detected. Along with this, testing the sensitivity of pseudomonads to protected carbapenems showed a better result. Moreover, clinical isolates of Pseudomonas spp. showed high resistance to fluoroquinolones and aminoglycosides. Conclusion. Acinetobacter spp. and Pseudomonas spp., isolated from patients with infectious and inflammatory diseases of the soft facial tissues have a rather low sensitivity to antibacterial drugs of various groups. Acinetobacter spp showed the highest sensitivity to gentamicin and amikacin. Pseudomonas possesses the highest sensitivity to cefiderocol, imipenem relabactam and meropenem verabactam.

Residual enrofloxacin in cattle manure increased persistence and dissemination risk of antibiotic resistance genes during anaerobic digestion

Anaerobic digestion is a common approach to dispose and recycle livestock manures, and the agricultural application of anaerobic digestives represents an important pathway of spreading antibiotic resistance genes (ARGs) from livestock manures to soils. Enrofloxacin is a clinically important fluoroquinolone antibiotic with high residual concentrations in livestock manure, and propagation of fluoroquinolone resistance genes poses a huge risk to public health. Compared with other antibiotics, enrofloxacin is relatively durable in anaerobic digestion system. However, its effect on the persistence of ARGs during anaerobic digestion and its mechanism are not clear. In this study, we investigated effects of 0, 4, and 8 mg/L enrofloxacin on the abundance, persistence, and transferring risk of five plasmid-mediated fluroquinolone ARGs and five typic clinically important non-fluoroquinolone ARGs during cattle manure digestion. The responses of integrons and microbial communities to enrofloxacin were assessed to uncover the underlying mechanisms. All the ten detected ARGs were highly persistent in anaerobic digestion, among them seven ARGs increased over 8.2 times after digestion. Network analysis revealed that the potential hosts of ARGs were critical functional taxa during anaerobic digestion, which can explain the high persistence of ARGs. Residual enrofloxacin significantly increased the abundance of aac(6′)-ib-cr, sul1, intI1, and intI2 throughout the digestion, but had no impact on the other ARGs, demonstrating its role in facilitating horizontal gene transfer of the plasmid-mediated aac(6′)-ib-cr. The influence of enrofloxacin on microbial communities disappeared at the end of digestion, but the ARG profiles remained distinctive between the enrofloxacin treatments and the control, suggesting the high persistence of enrofloxacin induced ARGs. Our results suggested the high persistence of ARGs in anaerobic digestion system, and highlighted the role of residual enrofloxacin in livestock manure in increasing dissemination risk of fluroquinolone resistance genes.

Prediction of functional proteins associated with the gut microbiome of an adult population in Lagos State, Nigeria

BackgroundThe human gut microbiome is implicated in health and disease. Yet, its functions in healthy adults from a divergent population like those seen in Africa are quite unclear. We set to reveal the roles of the gut microbiome of a healthy rural and urban Yoruba population of Lagos State. MethodologySociodemographic and clinical data, and fecal samples were obtained from rural (n = 10) and urban (n = 10) participants. fecal DNA extraction was done using ZR Fecal DNA MiniPrep™ D6010 and metagenomic next generation sequencing performed on Illumina Miseq platform. Functional roles prediction and antibiotics resistance genes (ARGs) were done using the Clusters of Orthologous Groups (COG) and Comprehensive Antibiotic Resistance Database (CARD) tools, respectively. The potential link between phenotypes and COG abundance were inferred using principal component analysis (PCA). ResultsWe found 12 (urban) and 11 (rural) COG classes of proteins from the gut microbes. Class E protein which denotes amino acid transport and metabolism was unique to urban respondents and was dominated by 5-enolpyruvylshikimate-3-phosphate synthase (45%) and asparagine synthase (30%), implying a high protein-based diet. Class S was found in both groups. COG families of proteins revealed the presence of exo-beta-1,3-glucanase (31%), pyruvate-decarboxylase, and thiamine pyrophosphate-requiring enzymes (22%) among the rural respondents’ indicative of carbohydrate-rich diets. In addition, uncharacterized protein linked to hypothetical functions was found in both. The COG proteins clustered with female sex, BMI (body mass index) and BP (blood pressure) for urban while for the rural populace, it clustered with height, BMI, and BP. CARD analysis showed ARGs in both groups (urban 90%; rural 10%) and all were Escherichia coli 16S rRNA (rrsB) mutation conferring resistance to streptomycin with gene variant model A523C n/a to aminoglycoside antibiotics. ConclusionThe study defined the classes of proteins from gut microbes of urban and rural respondents and highlighted the presence of uncharacterized proteins linked to hypothetical and unknown functions. Differences seen among the predicted roles appear to be driven by diet, clinical and sociodemographic factors. The higher abundance of ARGs observed in the urban population poses a serious public health concern with regards to the spread of antibiotic resistance.

Estuarine Aquacultures at the Crossroads of Animal Production and Antibacterial Resistance: A Metagenomic Approach to the Resistome.

It is recognized that the spread of antibiotic resistance (AR) genes among aquatic environments, including aquaculture and the human environment, can have detrimental effects on human and animal health and the ecosystem. Thus, when transmitted to the human microbiome or pathogens, resistance genes risk human health by compromising the eventual treatment of infections with antibiotic therapy. This study aimed to define the resistance profile of aquaculture farms and their potential risk for spreading. Twenty-four sediments from oyster and gilthead sea bream aquaculture farms located in three Portuguese river estuaries (17 sediments from Sado, 4 from Aveiro, and 3 from Lima) were studied by comparative metagenomic analysis. The computation of the diversity of genes conferring resistance per antibiotic class revealed a significant increase in aminoglycosides, beta-lactams, disinfectants, quinolones, and tetracyclines counts. In all geographic locations under study, the most diverse AR genes confer resistance to the macrolides, tetracyclines and oxazolidinones classes, all of which are medically important for human and animal therapies, as well as resistance to disinfectants. The diversity of mobile genetic elements correlated with the number of AR genes such as tetracyclines, suggesting that AR could be easily mobilized among bacterial genomes and microbiomes.

A STUDY OF BACTERIOLOGICAL AETIOLOGICAL AGENTS IN POST OPERATIVE ABDOMINAL WOUND INFECTIONS IN A TERTIARY CARE HOSPITAL

Background and Objectives: Surgical Site Infection (SSI) continues to be a major healthcareassociated infection. Primary objective: To isolate, identify and study the aerobic bacteriological spectrum of Abdominal Surgical Site Infection. Secondary objective: 1) To study the antibiotic sensitivity pattern. 2) To detect multidrug resistant strains in abdominal Surgical Site Infection. Materials and Methods: A total of 139 patients with post operative wound infections were included in this study during the course of one year from 1/10/16 to 30/09/2017. The study group included patients who underwent surgical procedure in a tertiary care hospital and developed Surgical Site Infection while in Hospital or after discharge within 30 days post surgery. These patients were followed up closely from the period of developing SSI to the time of discharge and during follow up in the hospital. Specimens such as double swabs for open surgical wounds and aspirates for localized infections were collected. Double swabs were inoculated into the following media: 5% Sheep Blood agar (SBA), MacConkey agar (MA), Salt agar (SA) and Glucose broth. Needle aspirates were also inoculated into Chocolate Agar (CA) in addition to the above media. The organisms were identied by conventional biochemical reactions and antibiotic sensitivity was done according to the CLSI guidelines 2017. Results: Out of the 139 cases in the study, the incidence of SSI's following abdominal surgeries were 41.7 %. The commonest age group for developing SSI was spread equally in the age groups between 51 – 60 and 61 – 70 years (20.14% each). Of the risk factors, Diabetes mellitus (40.28%) were associated with SSI's in 56 patients. Maximum number of cases were after Staging Laparotomies / Tumor excision for GIT Carcinoma- 48 (35.25%). 13.66 % cases were after Appendicectomy; LSCS - 12.23 %, Laparotomy- Peritonitis 10.79 %, Laparotomy- Intestinal obstruction 3.59 %, Hernioraphy 9.35 %, Tubectomy 3.59 %, TAH 7.19 %, Laparotomy -Abdominal injury 0.71 % and others 4.31 %. There were 58 (41.7%) of cases with microbial isolates and 81 (58.3%) cases were sterile. S.aureus was the predominant organism in Abdominal Surgical Site Infection 20 (34.48%), followed by E.coli and Klebsiella pneumoniae 15 (25.85%) each. Out of 15 Klebsiella pneumoniae 53.33 % were ESBL producers and 33.33 % were MBL producers. Where as in 15 E.coli isolates, 80 % were ESBL producers and 6.67 % MBL producers. Discussion: Surgical Site Infection (SSI) are the most common Health care associated infection in low and middle income countries. Surgical Site Infection was found to be higher in patients above 50 years of age which can be due to multiple factors like a low healing rate, malnutrition, mal-absorption, increased catabolic processes and low immunity. Diabetes mellitus is a major risk factor associated with Surgical Site Infections. Patients requiring prolonged hospitalization were more prone to Surgical Site Infections. Enterococcus which is a member of the normal ora of the Gastrointestinal and Genitourinary tract in humans is an emerging pathogen in abdominal Surgical Site Infections. Interpretation and Conclusion: The prevalence of multidrug resistant organisms is to be considered as a warning sign for the emerging spread of antibiotic resistance and the need for urgent implementation of strict antibiotic policy and infection control measures. Identication of SSI's involves interpretation of clinical and laboratory ndings, and it is crucial that a surveillance programme uses denitions that are consistent and standardized; otherwise inaccurate or uninterpretable SSI rates will be computed and reported.

Yeast Probiotic and Yeast Products in Enhancing Livestock Feeds Utilization and Performance: An Overview

The intensive use of antibiotics as growth-promoting agents in animal production has resulted in the spread of animal antibiotic resistance and possibly human antibiotic resistance. Based on this premise, it is significant to explore an alternative approach to preventing infectious diseases and promoting animal growth and health. Yeast as the main natural growth promoter in livestock nutrition has been extensively studied for decades. Numerous yeasts and yeast-containing products are produced, marketed, and used in animal feed as providers of nutrient sources, probiotics, and nutrients or serve distinct nutritional functions. A large amount of scientific research suggests that yeasts and their derivatives may be good for animal growth performance and health, especially when animals are housed in poor sanitation or are suffering from disease. However, when yeasts are used as a surrogate for livestock antibiotics, the results vary according to several factors, including yeast species, yeast product components, feed ingredients, animal category, type of symptoms, and differences in the rearing environment. In this review, the effects of different yeasts on different animals will be reviewed. The types of widely used yeast products, their functional characteristics, and application effects will be discussed in order to provide a reference for the development and application of yeast feed products.