Multi-drug resistant, biofilm-producing high-risk clonal lineage of Klebsiella in companion and household animals

Green synthesized silver nanoparticles from Ocimum sanctum: A potent inhibitor of biofilm forming ability and efflux pumps in bacteria causing bovine mastitis

Therapeutic management of mastitis faces significant challenges due to multidrug resistance. In the present study, multi-drug-resistant (MDR) Staphylococcus spp, Klebsiella pneumoniae, and Escherichia coli were isolated from bovine clinical mastitis cases and the phenotypic and genotypic multidrug resistance profiling was carried out. Silver nanoparticles (AgNPs) were biosynthesized using Ocimum sanctum leaf extracts and characterized via UV Vis absorption, Fourier Transform Infrared Spectroscopy, X-ray diffraction studies, Energy dispersive spectroscopy and Electron Microscopy. The determined minimum inhibitory concentration and minimum bactericidal concentration of the AgNPs against the recovered MDR isolates were 62.5 μg/ml and 125 μg/ml respectively. At a concentration of 50 μg/ml, the AgNPs demonstrated biofilm inhibitory activities of 80.35 % for MDR E. coli, 71.29 % for S. aureus and 60.18 % for MDR K. pneumoniae. Post-treatment observations revealed notable differences in biofilm formation across bacterial isolates. Furthermore, AgNP treatment led to significant downregulation of expression of the efflux pump genes acrB, acrE, acrF, and emrB in Gram-negative isolates and norB in Staphylococci isolates. This research underscores the potential for the development of an eco-friendly antimicrobial alternative in the form of green synthesized silver nanoparticles to combat drug resistance offering potential antibiofilm and efflux pump inhibitory activities.

Emerging Approaches for Mitigating Biofilm-Formation-Associated Infections in Farm, Wild, and Companion Animals

The importance of addressing the problem of biofilms in farm, wild, and companion animals lies in their pervasive impact on animal health and welfare. Biofilms, as resilient communities of microorganisms, pose a persistent challenge in causing infections and complicating treatment strategies. Recognizing and understanding the importance of mitigating biofilm formation is critical to ensuring the welfare of animals in a variety of settings, from farms to the wild and companion animals. Effectively addressing this issue not only improves the overall health of individual animals, but also contributes to the broader goals of sustainable agriculture, wildlife conservation, and responsible pet ownership. This review examines the current understanding of biofilm formation in animal diseases and elucidates the complex processes involved. Recognizing the limitations of traditional antibiotic treatments, mechanisms of resistance associated with biofilms are explored. The focus is on alternative therapeutic strategies to control biofilm, with illuminating case studies providing valuable context and practical insights. In conclusion, the review highlights the importance of exploring emerging approaches to mitigate biofilm formation in animals. It consolidates existing knowledge, highlights gaps in understanding, and encourages further research to address this critical facet of animal health. The comprehensive perspective provided by this review serves as a foundation for future investigations and interventions to improve the management of biofilm-associated infections in diverse animal populations.

Antibacterial and Anti-Biofilm Activities of Cinnamon Oil against Multidrug-Resistant Klebsiella pneumoniae Isolated from Pneumonic Sheep and Goats

The primary objectives were to isolate and identify Klebsiella pneumoniae (K. pneumoniae), and determine the antimicrobial resistance patterns and biofilm formation abilities of the isolates. Additionally, the study aimed to investigate the antimicrobial and anti-biofilm effects of cinnamon oil against K. pneumoniae isolates. A cross-sectional study was conducted from March 2022 to April 2023 to collect 200 samples (including 156 nasal swabs and 44 lung specimens) from pneumonic sheep and goats admitted to the Veterinary Teaching Hospital of Zagazig University, Egypt. K. pneumoniae was isolated from a total of 72 (36%) samples, with 53 (73.6%) isolates recovered from nasal swabs and 19 (26.4%) from lung samples. Among the samples, 52 (36.9%) were from sheep and 20 (33.9%) were from goats. Antimicrobial susceptibility testing of the 72 K. pneumoniae isolates to 18 antimicrobials revealed that all isolates were resistant to ampicillin, amoxicillin/clavulanic acid, cefotaxime, ceftriaxone, tetracycline, colistin, fosfomycin, and trimethoprim/sulphamethoxazole. None of the isolates were resistant to amikacin, imipenem, and norfloxacin. Multidrug resistance (MDR) was observed in all K. pneumoniae isolates recovered from sheep and goats. The average MAR index was 0.71, ranging from 0.50 to 0.83. Regarding biofilm formation, among the K. pneumoniae isolates with a high MAR index (n = 30), 10% exhibited strong formation, 40% showed moderate formation, 43.3% displayed weak formation, and 6.7% did not form biofilms. Additionally, the biofilm-forming genes treC and fimA were present in all 28 biofilm-forming K. pneumoniae isolates, while the mrkA gene was detected in 15 (53.6%) of the 28 isolates. MDR K. pneumoniae isolates with strong biofilm formation abilities were treated with cinnamon oil at varying concentrations (100%, 75%, 50%, and 25%). This treatment resulted in inhibition zone diameters ranging from 35 to 45 mm. Cinnamon oil exhibited lower minimum inhibitory concentration and minimum bactericidal concentration values compared to norfloxacin for all isolates. Additionally, cinnamon oil significantly reduced the expression of biofilm-associated genes (treC, fimA, and mrkA) when compared to isolates treated with norfloxacin or untreated. In conclusion, this study identified a high level of MDR K. pneumoniae with strong and moderate biofilm formation abilities in pneumonic sheep and goats in Sharika Governorate, Egypt. Although cinnamon oil demonstrated potential antibacterial and anti-biofilm properties against K. pneumoniae, further research is required to investigate its effectiveness in treating K. pneumoniae infections in pneumonic sheep and goats.

Exploring the prevalence and antibiotic resistance profile of Klebsiella pneumoniae and Klebsiella oxytoca isolated from clinically ill companion animals from North of Portugal

Klebsiella spp. is an important pathogen in humans and animals and due to the indiscriminate use of antibiotics, its prevalence and antibiotic resistance has increased in companion animals. The main goal of this study was to investigate the prevalence and antibiotic resistance of Klebsiella spp. isolated from clinically ill cats and dogs admitted in veterinary clinics in the North of Portugal. A total of 255 clinical specimens were collected and, after isolation, the identification of Klebsiella strains was performed using the BBL Crystal™ identification system and confirmed by PCR-based sequencing with specific primers. Antibiotic resistance profile was determined through the disc diffusion method. Beta-lactam resistance genes were screened through a multiplex PCR assay. Fifty Klebsiella strains were isolated and, 39 were identified as Klebsiella pneumoniae and 11 as Klebsiella oxytoca. Thirty-one were recovered from dogs and 19 from cats. The Klebsiella isolates were recovered mainly from skin wounds, respiratory tract, and from urine. Fifty percent of K. oxytoca and K. pneumoniae isolates revealed to be Multidrug Resistant (MDR) strains, with most of them positive for the presence of blaTEM-like and blaSHV genes. This data shows that MDR Klebsiella are highly disseminated in companion animals and that extended-spectrum beta-lactamases can be easily found among these isolates. This highlights the potential role of dogs and cats as a reservoir of resistant Klebsiella spp. that have the potential to be transmitted to humans.

One Health approaches adapted in low resource settings to address antimicrobial resistance

Inter-disciplinary collaborations are now considered as key factors for integrated health system strengthening. Its application in the domain of One Health needs more milestones to achieve. Other than the human health sector, the antimicrobials are used in food animals and aquaculture for therapy, prophylaxis and growth promotion which significantly contributes to the development of antimicrobial resistance. It is the high time to develop a sustainable collaboration between the concerned sectors of One Health for a resilient health system. The domain of One Health not only mitigates the emergence of antimicrobial resistance but also helps in realizing the surveillance and epidemiology of zoonotic diseases, and the control of public health emergencies such as COVID-19. The review identified the key One Health strategies adapted by India, the exemplary low resource settings, to address antimicrobial resistance and zoonosis.

Attitude, Opinions, and Working Preferences Survey among Pet Practitioners Relating to Antimicrobials in India

The indiscriminate usage and overuse of antimicrobials in pets or companion animals are underlying causes of antimicrobial resistance (AMR). Despite the multi-faceted global challenge presented by antimicrobial resistance, very few studies have appraised pet practitioners’ factors, such as written policy on antimicrobials, dose rate prescribed, use of critically important antimicrobials, and antimicrobial prescription in clean surgical procedures, which can contribute to AMR. In the present study, an online cross-sectional survey among randomly selected pet practitioners (n = 104) of various Indian provinces and union territories was conducted using a questionnaire comprising 33 closed-ended questions on different parameters, viz., the dosage regimen and level of compliance towards guidelines of the World Health Organization (WHO), other relevant veterinary associations, and their opinion while prescribing antimicrobials. Almost every practitioner of the 104 respondents had revealed the difficulties with owner compliance; i.e., incomplete course of the antibiotics, inappropriate follow-ups, and improper care of the sick animals. The majority of practitioners (95%) reported self-prescription of antimicrobials by the owner before presenting the pet(s) to the veterinary clinic, whereas more than half of the respondents (64%) revealed unavailability of antibiogram facilities. Furthermore, a large number (76%) of practitioners stated empirical treatment based on their experience as the main criteria for antimicrobial choice in the absence of timely results from the laboratory. Although non-necessitated use of antimicrobials in clean surgical procedures has been claimed, surprisingly, the majority of pet practitioners (97%) reported their use to reduce the post-operative complications. The use of the highest priority, critically important antimicrobials (HPCIA) listed by the WHO for humans, particularly quinolones and third-generation cephalosporin, also has been reported for different infections. The treatment durations were nearly as per the recommended guidelines issued by the Danish Small Animal Veterinary Association (DSAVA) for different ailments. Analysis using chi-square tests exhibited a significant correlation between less experienced veterinarians (less than 5 years) and prescription of antimicrobials restricted for critically important infections in human medicine. However, there seems to be no association between the experience of the practitioner and the further studied parameters, namely, antimicrobial regimen prescription, weighing the animals before prescription, dose rate calculation, and antimicrobial selection and use after clean surgical operations. The findings suggest periodic awareness campaigns among practitioners regarding the implementation of the official guidelines, the need for systematic surveillance of AMR, awareness among pet owners about antimicrobial resistance, and the importance of rational use of antimicrobials on their pets.

How Good are Bacteriophages as an Alternative Therapy to Mitigate Biofilms of Nosocomial Infections

Bacteria survive on any surface through the generation of biofilms that provide a protective environment to grow as well as making them drug resistant. Extracellular polymeric matrix is a crucial component in biofilm formation. The presence of biofilms consisting of common opportunistic and nosocomial, drug-resistant pathogens has been reported on medical devices like catheters and prosthetics, leading to many complications. Several approaches are under investigation to combat drug-resistant bacteria. Deployment of bacteriophages is one of the promising approaches to invade biofilm that may expose bacteria to the conditions adverse for their growth. Penetration into these biofilms and their destruction by bacteriophages is brought about due to their small size and ability of their progeny to diffuse through the bacterial cell wall. The other mechanisms employed by phages to infect biofilms may include their relocation through water channels to embedded host cells, replication at local sites followed by infection to the neighboring cells and production of depolymerizing enzymes to decompose viscous biofilm matrix, etc. Various research groups are investigating intricacies involved in phage therapy to mitigate the bacterial infection and biofilm formation. Thus, bacteriophages represent a good control over different biofilms and further understanding of phage-biofilm interaction at molecular level may overcome the clinical challenges in phage therapy. The present review summarizes the comprehensive details on dynamic interaction of phages with bacterial biofilms and the role of phage-derived enzymes - endolysin and depolymerases in extenuating biofilms of clinical and medical concern. The methodology employed was an extensive literature search, using several keywords in important scientific databases, such as Scopus, Web of Science, PubMed, ScienceDirect, etc. The keywords were also used with Boolean operator "And". More than 250 relevant and recent articles were selected and reviewed to discuss the evidence-based data on the application of phage therapy with recent updates, and related potential challenges.

Elucidating the resistance repertoire, biofilm production, and phylogenetic characteristics of multidrug-resistant Escherichia coli isolated from community ponds: A study from West Bengal, India

This study details about the phenotypic and molecular characteristics of multidrug-resistant (MDR) Escherichia coli in the fresh community pond water (n = 257) collected from three districts of West Bengal, India. In total, 57 isolates were MDR of which 38 emerged as extended spectrum and 7 as AmpC-type β-lactamase producers in phenotypic assay. Among β-lactamase genes, blaCTXM-1was predominant (87.71%) followed by blaAmpC (77.2%) and blaTEM-1 (22.8%). Six MDR strains carried metallo-β-lactamase (MBL, blaNDM-1) gene. Tissue culture plate assay confirmed strong biofilm (SP) production in four MDR and one non-MDR isolates. In PCR-based replicon typing (PBRT), multiple plasmids of diverse replicon types (Frep, FIB, I1, FIA, K/B, HI1, and Y) were identified. The enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR)-based phylogenetic analysis revealed a high degree of genetic divergence among the MDR isolates. Multiplex PCR-based phylogrouping categorized 11 isolates as virulent (B2/D/F), which carried blaCTXM-1 gene and three had blaNDM-1 gene. Relative transcriptional activity of AcrAB efflux pump was significantly elevated among the SP and MBL producers. The presence of MDR E. coli isolates, particularly those resistant to carbapenem, in pond water used for daily domestic and household work, is a cause of concern as these pathogens may sneak into human food chain causing life-threatening infections. PRACTITIONER POINTS: Multidrug-resistant biofilm producing E. coli isolated from community pond water. A few of them were carbapenem-resistant and belonged to virulent (B2/D) types. Expression of AcrAB efflux pumps was found significantly elevated among biofilm producers and carbapenem-resistant population.

Bacteriophage-Derived Depolymerases against Bacterial Biofilm

In addition to specific antibiotic resistance, the formation of bacterial biofilm causes another level of complications in attempts to eradicate pathogenic or harmful bacteria, including difficult penetration of drugs through biofilm structures to bacterial cells, impairment of immunological response of the host, and accumulation of various bioactive compounds (enzymes and others) affecting host physiology and changing local pH values, which further influence various biological functions. In this review article, we provide an overview on the formation of bacterial biofilm and its properties, and then we focus on the possible use of phage-derived depolymerases to combat bacterial cells included in this complex structure. On the basis of the literature review, we conclude that, although these bacteriophage-encoded enzymes may be effective in destroying specific compounds involved in the formation of biofilm, they are rarely sufficient to eradicate all bacterial cells. Nevertheless, a combined therapy, employing depolymerases together with antibiotics and/or other antibacterial agents or factors, may provide an effective approach to treat infections caused by bacteria able to form biofilms.

Insects, Rodents, and Pets as Reservoirs, Vectors, and Sentinels of Antimicrobial Resistance

This paper reviews the occurrence of antimicrobial resistance (AMR) in insects, rodents, and pets. Insects (e.g., houseflies, cockroaches), rodents (rats, mice), and pets (dogs, cats) act as reservoirs of AMR for first-line and last-resort antimicrobial agents. AMR proliferates in insects, rodents, and pets, and their skin and gut systems. Subsequently, insects, rodents, and pets act as vectors that disseminate AMR to humans via direct contact, human food contamination, and horizontal gene transfer. Thus, insects, rodents, and pets might act as sentinels or bioindicators of AMR. Human health risks are discussed, including those unique to low-income countries. Current evidence on human health risks is largely inferential and based on qualitative data, but comprehensive statistics based on quantitative microbial risk assessment (QMRA) are still lacking. Hence, tracing human health risks of AMR to insects, rodents, and pets, remains a challenge. To safeguard human health, mitigation measures are proposed, based on the one-health approach. Future research should include human health risk analysis using QMRA, and the application of in-silico techniques, genomics, network analysis, and ’big data’ analytical tools to understand the role of household insects, rodents, and pets in the persistence, circulation, and health risks of AMR.