Evaluation of efflux pump activity of multidrug-resistant Salmonella Typhimurium isolated from poultry wet markets in India

Ocimum basilicum and Lagenaria siceraria Loaded Lignin Nanoparticles as Versatile Antioxidant, Immune Modulatory, Anti-Efflux, and Antimicrobial Agents for Combating Multidrug-Resistant Bacteria and Fungi

Lignin nanoparticles emerged as a promising alternative for drug delivery systems owing to their biodegradability and bioactive properties. This study investigated the antimicrobial activity of the ethanolic extract of Ocimum basilicum-loaded lignin nanoparticles (OB-LNPs) and Lagenaria siceraria seed oil-loaded lignin nanoparticles (LS-LNPs) to find a solution for antimicrobial resistance. OB-LNPs and LS-LNPs were tested for their antimicrobial potential against Escherichia coli, Enterococcus faecalis, Klebsiella pneumoniae, Staphylococcus aureus, Salmonella enterica, Trichophyton mentagrophytes, Trichophyton rubrum, and Microsporum canis. OB-LNPs and LS-LNPs were further tested for their anti-efflux activity against ciprofloxacin-resistant Salmonella enterica strains and for treating Salmonella infection in a rat model. We also investigated the antifungal efficacy of OB-LNPs and LS-LNPs for treating T. rubrum infection in a guinea pig model. Both OB-LNPs and LS-LNPs showed strong antimicrobial potential against S. Typhimurium and T. rubrum infections. LS-LNPs showed antibacterial activity against Salmonella enterica species with a MIC range of 0.5-4 µg/mL and antifungal activity against T. rubrum with a MIC range of 0.125-1 µg/mL. OB-LNPs showed antibacterial activity against Salmonella enterica species with a MIC range of 0.5-2 µg/mL and antifungal activity against T. rubrum with a MIC range of 0.25-2 µg/mL. OB-LNPs and LS-LNPs downregulated the expression of ramA and acrB efflux pump genes (fold change values ranged from 0.2989 to 0.5434; 0.4601 to 0.4730 for ramA and 0.3842-0.6199; 0.5035-0.8351 for acrB). Oral administration of OB-LNPs and LS-LNPs in combination with ciprofloxacin had a significant effect on all blood parameters, as well as on liver and kidney function parameters. Oxidative stress mediators, total antioxidant capacity, and malondialdehyde were abolished by oral administration of OB-LNPs and LS-LNPs (0.5 mL/rat once daily for 5 days). Interferon-γ and tumor necrosis factor-α were also reduced in comparison with the positive control group and the ciprofloxacin-treated group. Histopathological examination of the liver and intestine of OB-LNPs and LS-LNPs-treated rats revealed an elevation in Salmonella clearance. Treatment of T. rubrum-infected guinea pigs with OB-LNPs and LS-LNPs topically in combination with itraconazole resulted in a reduction in lesion scores, microscopy, and culture results. In conclusion, OB-LNPs and LS-LNPs possess immunomodulatory and antioxidant potential and can be used as naturally derived nanoparticles for drug delivery and treatment of Salmonellosis and dermatophytosis infections.

Analysis of mcr family of colistin resistance genes in Gram-negative isolates from a tertiary care hospital in India

AIM

Colistin serves as the drug of last resort for combating numerous multidrug-resistant (MDR) Gram-negative infections. Its efficacy is hampered by the prevalent issue of colistin resistance, which severely limits treatment options for critically ill patients. Identifying resistance genes is crucial for controlling resistance spread, with horizontal gene transfer being the primary mechanism among bacteria. This study aimed to assess the prevalence of plasmid-mediated mcr genes associated with colistin resistance in Gram-negative bacteria, utilizing both genotypic and phenotypic tests.

METHODS AND RESULTS

The clinical isolates (n = 913) were obtained from a tertiary care center in Chennai, India. Colistin resistance was seen among Gram-negative isolates. These strains underwent screening for mcr-1, mcr-3, mcr-4, and mcr-5 genes via conventional PCR. Additionally, mcr-positive isolates were confirmed through Sanger sequencing and phenotypic testing. The bacterial isolates predominantly comprised Klebsiella pneumoniae (62.43%), Escherichia coli (19.71%), Pseudomonas aeruginosa (10.73%), and Acinetobacter baumannii (4.81%), along with other species. All isolates exhibited multidrug resistance to three or more antibiotic classes. Colistin resistance, determined via broth microdilution (BMD) using CLSI guidelines, was observed in 13.08% of the isolates studied. Notably, mcr-5 was detected in K. pneumoniae in PCR, despite its absence in Sanger sequencing and phenotypic tests (including the combined-disk test, colistin MIC in the presence of EDTA, and Zeta potential assays). This finding underscores the importance of employing multiple diagnostic approaches to accurately identify colistin resistance mechanisms.

Prevalence and antimicrobial susceptibility of Salmonella enteritidis and Salmonella typhimurium isolated from hen eggs and quail eggs in Karaj, Iran

BACKGROUND AND AIM

Different Salmonella serotypes are considered one of the most important food pathogens in the world. Poultry meat and eggs are the primary carriers of Salmonella in human populations. This study aimed to estimate the Salmonella enteritidis and Salmonella typhimurium contamination rates of retail hen and quail eggs in Karaj, Iran. Moreover, the antimicrobial resistance patterns of the strains were evaluated, and the efficiency of the standard culture method and multiplex polymerase chain reaction (m-PCR) were compared.

MATERIALS AND METHODS

In this descriptive cross-sectional study over 1 year (Jan-Dec 2022), 150 commercial and 150 backyard hen eggs and 300 commercial quail eggs, without cracks and fractures, were collected randomly from best selling groceries in Karaj city. All samples were examined for Salmonella contamination independently by standard culture and m-PCR approaches. A standard disc diffusion method was employed to assess the antimicrobial susceptibility of the strains against 18 antimicrobial agents.

RESULTS

Out of 300 examined eggs, 2 S. enteritidis strains were isolated from the shell of backyard hen eggs. The same serotype was also detected in the contents of one of these two eggs. One S. typhimurium was isolated from the shell of a commercial hen egg. Overall, the Salmonella contamination of the shell and contents was 1% and 0.3%, respectively. Salmonella was not isolated from the eggshells or the contents of the quail eggs. There was complete agreement between the results of m-PCR and the standard culture methods. Among the 18 tested antibiotics, the highest resistance was recorded for colistin (100%), followed by nalidixic acid (75%).

CONCLUSION

As most Salmonella spp. are associated with human food poisoning, continuous surveillance is required to effectively reduce the risk posed by contaminated poultry eggs. Furthermore, mandatory monitoring of antimicrobial use on Iranian poultry farms is recommended.

Prevalence of Antimicrobial Resistance Among the Hydrogen Sulfide Producing Bacteria Isolated on XLD Agar from the Poultry Fecal Samples

Poultry products remain as one of the most popular and extensively consumed foods in the world and the introduction of hydrogen sulfide (H2S) producing antibiotic resistant bacterial species into it is an emerging challenge. The current study has been designed to analyze the distribution of antibiotic resistance among the H2S producing bacteria isolated from the fecal samples of chickens from different poultry farms. Here, twenty bacterial isolates were selected based on their ability to produce H2S on XLD agar, and the16S rDNA sequencing was carried out for their molecular identification. The results showed the isolates as belong to Salmonella spp. and Citrobacter spp. and in the antibiotic susceptibility test (AST), three of the Salmonella strains were found to be resistant to antibiotics such as tetracycline, doxycycline, nalidixic acid, and amikacin. Also, fourteen Citrobacter strains showed resistance towards azithromycin, and furthermore, eleven of them were also resistant to streptomycin. Resistance towards tetracycline was observed among five of the Citrobacter strains, and seven were resistant to doxycycline. Further molecular screening by the PCR has showed three of the Salmonella strains along with eight Citrobacter isolates to have tetA gene along with four of the Citrobacter strains to have co-harbored blaTEM gene. The results on biofilm formation have also demonstrated three Salmonella strains along with nine Citrobacter strains to have the ability to form moderate biofilm. The study thus describes the occurrence of H2S producing multidrug-resistant bacteria in poultry feces, which might contribute towards the dissemination of antibiotic resistance genes to other microorganisms including human pathogens with likely risk to treat disease conditions.

Outer Membrane Proteins and Efflux Pumps Mediated Multi-Drug Resistance in Salmonella: Rising Threat to Antimicrobial Therapy

Despite colossal achievements in antibiotic therapy in recent decades, drug-resistant pathogens have remained a leading cause of death and economic loss globally. One such WHO-critical group pathogen is Salmonella. The extensive and inappropriate treatments for Salmonella infections have led from multi-drug resistance (MDR) to extensive drug resistance (XDR). The synergy between efflux-mediated systems and outer membrane proteins (OMPs) may favor MDR in Salmonella. Differential expression of the efflux system and OMPs (influx) and positional mutations are the factors that can be correlated to the development of drug resistance. Insights into the mechanism of influx and efflux of antibiotics can aid in developing a structurally stable molecule that can be proficient at escaping from the resistance loops in Salmonella. Understanding the strategic responsibilities and developing policies to address the surge of drug resistance at the national, regional, and global levels are the needs of the hour. In this Review, we attempt to aggregate all the available research findings and delineate the resistance mechanisms by dissecting the involvement of OMPs and efflux systems. Integrating major OMPs and the efflux system's differential expression and positional mutation in Salmonella may provide insight into developing strategic therapies for one health application.

Assesment of polyphenolic compounds against biofilms produced by clinical Acinetobacter baumannii strains using in silico and in vitro models

Several types of microbial infections are caused by Acinetobacter baumanii that has developed resistance to antimicrobial agents. We therefore investigated the role of plant polyphenols against A. baumannii using in silico and in vitro models. The clinical strains of A. baumannii were investigated for determination of resistance pattern and resistance mechanisms including efflux pump, extended spectrum beta lactamase, phenotype detection of AmpC production, and Metallo-β-lactamase. The polyphenolic compounds were docked against transcription regulator BfmR (PDB ID 6BR7) and antimicrobial, antibiofilm, and anti-quorum sensing activities were performed. The antibiogram studies showed that all isolated strains were resistant. Strain A77 was positive in Metallo-β-lactamase production. Similarly, none of strains were producers of AmpC, however, A77, A76, A75 had active efflux pumps. Molecular docking studies confirmed a strong binding affinity of Rutin and Catechin towards transcription regulator 6BR7. A significant antimicrobial activity was recorded in case of quercetin and syringic acid (MIC 3.1 µg/mL) followed by vanillic acid and caffeic acid (MIC 12.5 µg/mL). All tested compounds presented a strong antibiofilm activity against A. baumanii strain A77 (65 to 90%). It was concluded that all tested polyphenols samples posess antimicrobial and antibiofilm activities, and hence they may be utilized to treat multidrug resistance A. baumannii infections.

Prevalence and characterization of quinolone-resistant Escherichia coli isolated from retail raw beef and poultry meat in Egypt

Objective

The goal of this study was to look at quinolone-resistant (QR) Escherichia coli (E. coli) from retail beef and poultry meat in Egypt by looking at the QR mechanisms in the resistant strains.

Materials and Methods

In total, 120 samples of raw poultry meat (n = 60) and beef meat (n = 60) were purchased from Mansoura retail stores between January and March 2021, and evaluated microbiologically for E. coli. Then, an antimicrobial sensitivity test was applied to all isolates. The prevalence of QR E. coli with concern for the QR determinants, including quinolone resistance-determining regions (QRDRs) mutations, the plasmid-mediated quinolone resistance gene (PMQR), and the efflux pump activity were determined.

Results

The total prevalence of E. coli was 34.2% (41/120). Noticeably, the prevalence of E. coli in poultry meat (40%, 24/60) was higher than that of beef (28%, 17/60). All strains were assessed for their antimicrobial susceptibility using the disc diffusion technique; the highest rate of resistance (100%) was displayed to clindamycin and cefuroxime, followed by ampicillin (97.6%), doxycycline (92.7%), amoxicillin-clavulanate (92.7%), nalidixic acid (NA) (80.5%), sulfamethoxazole/trimethoprim (70.7%), chloramphenicol (63.4%), gentamicin, and azithromycin (58.5% each). Multiple antimicrobial resistance (strains resistant to three or more antimicrobial classes) was displayed by 97.6% of E. coli isolates. Regarding QR, 37 isolates could resist at least one of the examined quinolones. Regarding PMQR genes, qnrS was determined in 70% (7/10) of QR E. coli, while qnrA, qnrB, and qnrD were not identified. While the mutations determined regions of QR in the resistant E. coli isolates, S83L was the most prevalent in gyrase subunit A either alone or combined with D87N and D87Y, and three isolates of QR E. coli isolates revealed a topoisomerase IV subunit mutation harboring S80I. 20% of the isolates displayed efflux activity, as NA showed a considerable difference between its zones of inhibition.

Conclusion

The high prevalence of antimicrobial-resistant E. coli, with concern for QR strains harboring different resistance mechanisms in poultry meat and beef, threatens the public's health. Thus, standard manufacturing procedures and adequate hygiene conditions must be followed in all phases of meat preparation, production, and consumption, and public knowledge should be improved.

Role of bacterial efflux pump proteins in antibiotic resistance across microbial species

Efflux proteins are transporter molecules that actively pump out a variety of substrates, including antibiotics, from cells to the environment. They are found in both Gram-positive and Gram-negative bacteria and eukaryotic cells. Based on their protein sequence homology, energy source, and overall structure, efflux proteins can be divided into seven groups. Multidrug efflux pumps are transmembrane proteins produced by microbes to enhance their survival in harsh environments and contribute to antibiotic resistance. These pumps are present in all bacterial genomes studied, indicating their ancestral origins. Many bacterial genes encoding efflux pumps are involved in transport, a significant contributor to antibiotic resistance in microbes. Efflux pumps are widely implicated in the extrusion of clinically relevant antibiotics from cells to the extracellular environment and, as such, represent a significant challenge to antimicrobial therapy. This review aims to provide an overview of the structures and mechanisms of action, substrate profiles, regulation, and possible inhibition of clinically relevant efflux pumps. Additionally, recent advances in research and the pharmacological exploitation of efflux pump inhibitors as a promising intervention for combating drug resistance will be discussed.

Assessment of multidrug-resistant profile, multi-locus sequence typing and efflux pump activity in Salmonella Typhimurium isolated from hospital sewage

Salmonella enterica serovar Typhimurium is becoming a leading cause of gastroenteritis and mortality. The use of antibiotics has increased natural resistance of S. Typhimurium to antibiotics. This study aims to isolate and characterize multi-drug-resistant (MDR) Salmonella strains from hospital sewage samples in Bhopal City, central India. The MDR isolates were characterized by molecular identification, antimicrobial resistance patterns, multi-locus sequence typing, and efflux pump activity. Specific genes (hilA, stn, invA, typh, and iroB) were used to confirm S. Typhimurium isolates. The Kirbey-Bauer method was employed to profile antimicrobial resistance using 20 antibiotics. Multi-locus sequence typing confirmed S. Typhimurium using seven housekeeping genes (aroC, dnaN, hemD, hisD, purE, sucA, and thr). Out of five strains, only four were confirmed as S. Typhimurium during MLST analysis. Efflux pump activity was determined using the ethidium bromide (EtBr) cartwheel test. Of the 160 isolates, 38 were presumptively confirmed as S. Typhimurium based on biochemical characterization, and only five MDR Salmonella strains were selected for their resistance against most antibiotics. Efflux pump activity revealed that five out of the four MDR isolates did not retain EtBr inside the cells, indicating pronounced efflux activity. Additionally, the isolated strains showed a specific correlation between the antimicrobial phenotypes and genotypes. The results of this study provide a better understanding of the characterization of S. Typhimurium serotype in Bhopal City. Future studies should focus on understanding changing antimicrobial resistance patterns, pathogenicity, and the genetic background of Salmonella serotypes. Further surveillance activities for antimicrobial-resistant Salmonella in different environmental sources should be prioritized.

Biochemical and molecular mechanisms of antibiotic resistance in Salmonella spp

Salmonella is a diverse Gram-negative bacterium that represents the major disease burden worldwide. According to WHO, Salmonella is one of the fourth global causes of diarrhoeal disease. Antibiotic resistance is a worldwide health concern, and Salmonella spp. is one of the microorganisms that can evade the toxicity of antimicrobials via antibiotic resistance. This review aims to deliver in-depth knowledge of the molecular mechanisms and the underlying biochemical alterations perceived in antibiotic resistance in Salmonella. This information will help understand and mitigate the impact of antibiotic-resistant bacteria on humans and contribute to the state-of-the-art research developing newer and more potent antibiotics.

Antidiarrheal and Antibacterial Activities of Monterey Cypress Phytochemicals: In Vivo and In Vitro Approach

Monterey cypress (Cupressus macrocarpa) is a decorative plant; however, it possesses various pharmacological activities. Therefore, we explored the phytochemical profile of C. macrocarpa root methanol extract (CRME) for the first time. Moreover, we investigated its antidiarrheal (in vivo), antibacterial, and antibiofilm (in vitro) activities against Salmonella enterica clinical isolates. The LC-ESI-MS/MS analysis of CRME detected the presence of 39 compounds, besides isolation of 2,3,2″,3″-tetrahydro-4'-O-methyl amentoflavone, amentoflavone, and dihydrokaempferol-3-O-α-l-rhamnoside for the first time. Dihydrokaempferol-3-O-α-l-rhamnoside presented the highest antimicrobial activity and the range of values of MICs against S. enterica isolates was from 64 to 256 µg/mL. The antidiarrheal activity of CRME was investigated by induction of diarrhea using castor oil, and exhibited a significant reduction in diarrhea and defecation frequency at all doses, enteropooling (at 400 mg/kg), and gastrointestinal motility (at 200, 400 mg/kg) in mice. The antidiarrheal index of CRME increased in a dose-dependent manner. The effect of CRME on various membrane characters of S. enterica was studied after typing the isolates by ERIC-PCR. Its impact on efflux and its antibiofilm activity were inspected. The biofilm morphology was observed using light and scanning electron microscopes. The effect on efflux activity and biofilm formation was further elucidated using qRT-PCR. A significant increase in inner and outer membrane permeability and a significant decrease in integrity and depolarization (using flow cytometry) were detected with variable percentages. Furthermore, a significant reduction in efflux and biofilm formation was observed. Therefore, CRME could be a promising source for treatment of gastrointestinal tract diseases.

Extensive Drug-Resistant Salmonella enterica Isolated From Poultry and Humans: Prevalence and Molecular Determinants Behind the Co-resistance to Ciprofloxacin and Tigecycline

The emergence of extensive drug-resistant (XDR) Salmonella in livestock animals especially in poultry represents a serious public health and therapeutic challenge. Despite the wealth of information available on Salmonella resistance to various antimicrobials, there have been limited data on the genetic determinants of XDR Salmonella exhibiting co-resistance to ciprofloxacin (CIP) and tigecycline (TIG). This study aimed to determine the prevalence and serotype diversity of XDR Salmonella in poultry flocks and contact workers and to elucidate the genetic determinants involved in the co-resistance to CIP and TIG. Herein, 115 Salmonella enterica isolates of 35 serotypes were identified from sampled poultry (100/1210, 8.26%) and humans (15/375, 4.00%), with the most frequent serotype being Salmonella Typhimurium (26.96%). Twenty-nine (25.22%) Salmonella enterica isolates exhibited XDR patterns; 25 out of them (86.21%) showed CIP/TIG co-resistance. Exposure of CIP- and TIG-resistant isolates to the carbonyl cyanide 3-chlorophenylhydrazone (CCCP) efflux pump inhibitor resulted in an obvious reduction in their minimum inhibitory concentrations (MICs) values and restored the susceptibility to CIP and TIG in 17.24% (5/29) and 92% (23/25) of the isolates, respectively. Molecular analysis revealed that 89.66% of the isolates contained two to six plasmid-mediated quinolone resistance genes with the predominance of qepA gene (89.66%). Mutations in the gyrA gene were detected at codon S83 (34.62%) or D87 (30.77%) or both (34.62%) in 89.66% of XDR Salmonella. The tet(A) and tet(X4) genes were detected in 100% and 3.45% of the XDR isolates, respectively. Twelve TIG-resistant XDR Salmonella had point mutations at codons 120, 121, and 181 in the tet(A) interdomain loop region. All CIP and TIG co-resistant XDR Salmonella overexpressed ramA gene; 17 (68%) out of them harbored 4-bp deletion in the ramR binding region (T-288/A-285). However, four CIP/TIG co-resistant isolates overexpressed the oqxB gene. In conclusion, the emergence of XDR S. enterica exhibiting CIP/TIG co-resistance in poultry and humans with no previous exposure to TIG warrants an urgent need to reduce the unnecessary antimicrobial use in poultry farms in Egypt.

Ethidium Binding to Salmonella enterica ser. Typhimurium Cells and Salmon Sperm DNA

Bacterial resistance to antibiotics due to increased efficiency of the efflux is a serious problem in clinics of infectious diseases. Knowledge of the factors affecting the activity of efflux pumps would help to find the solution. For this, fast and trustful methods for efflux analysis are needed. Here, we analyzed how the assay conditions affect the accumulation of efflux indicators ethidium (Et⁺) and tetraphenylphosphonium in Salmonella enterica ser. Typhimurium cells. An inhibitor phenylalanyl-arginyl-β-naphtylamide was applied to evaluate the input of RND family pumps into the total efflux. In parallel to spectrofluorimetric analysis, we used an electrochemical assessment of Et⁺ concentration. The results of our experiments indicated that Et⁺ fluorescence increases immediately after the penetration of this indicator into the cells. However, when cells bind a high amount of Et⁺, the intensity of the fluorescence reaches the saturation level and stops reacting to the accumulated amount of this indicator. For this reason, electrochemical measurements provide more trustful information about the efficiency of efflux when cells accumulate high amounts of Et⁺. Measurements of Et⁺ interaction with the purified DNA demonstrated that the affinity of this lipophilic cation to DNA depends on the medium composition. The capacity of DNA to bind Et⁺ considerably decreases in the presence of Mg²⁺, Polymyxin B or when DNA is incubated in high ionic strength media.

Tannic Acid-Stabilized Silver Nanoparticles Used in Biomedical Application as an Effective Antimelioidosis and Prolonged Efflux Pump Inhibitor against Melioidosis Causative Pathogen

Burkholderia pseudomallei is the causative pathogen of melioidosis and this bacterium is resistant to several antibiotics. Silver nanoparticles (AgNPs) are an interesting agent to develop to solve this bacterial resistance. Here, we characterize and assess the antimelioidosis activity of AgNPs against these pathogenic bacteria. AgNPs were characterized and displayed a maximum absorption band at 420 nm with a spherical shape, being well-monodispersed and having high stability in solution. The average size of AgNPs is 7.99 ± 1.46 nm. The antibacterial efficacy of AgNPs was evaluated by broth microdilution. The bactericidal effect of AgNPs was further assessed by time-kill kinetics assay. Moreover, the effect of AgNPs on the inhibition of the established biofilm was investigated by the crystal violet method. In parallel, a study of the resistance induction development of B. pseudomallei towards AgNPs with efflux pump inhibiting effect was performed. We first found that AgNPs had strong antibacterial activity against both susceptible and ceftazidime-resistant (CAZ-resistant) strains, as well as being efficiently active against B. pseudomallei CAZ-resistant strains with a fast-killing mode via a bactericidal effect within 30 min. These AgNPs did not only kill planktonic bacteria in broth conditions, but also in established biofilm. Our findings first documented that the resistance development was not induced in B. pseudomallei toward AgNPs in the 30th passage. We found that AgNPs still showed an effective efflux pump inhibiting effect against these bacteria after prolonged exposure to AgNPs at sublethal concentrations. Thus, AgNPs have valuable properties for being a potent antimicrobial agent to solve the antibiotic resistance problem in pathogens.

Evaluation of efflux pump activity and biofilm formation in multidrug resistant clinical isolates of Pseudomonas aeruginosa isolated from a Federal Medical Center in Nigeria

Background

Pseudomonas aeruginosa an opportunistic pathogen, is widely associated with nosocomial infections and exhibits resistance to multiple classes of antibiotics. The aim of this study was to determine the antibiotic resistance profile, biofilm formation and efflux pump activity of Pseudomonas strains isolated from clinical samples in Abeokuta Ogun state Nigeria.

Methods

Fifty suspected Pseudomonas isolates were characterized by standard biochemical tests and PCR using Pseudomonas species -specific primers. Antibiotic susceptibility testing was done by the disc diffusion method. Efflux pump activity screening was done by the ethidium bromide method and biofilm formation assay by the tissue plate method. Genes encoding biofilm formation (pslA & plsD) and efflux pump activity (mexA, mexB and oprM) were assayed by PCR.

Results

Thirty-nine Pseudomonas spp. were identified of which 35 were Pseudomonas aeruginosa and 4 Pseudomonas spp. All 39 (100%) Pseudomonas isolates were resistant to ceftazidime, cefuroxime and amoxicillin-clavulanate. Thirty-six (92%), 10(25.6%), 20 (51.2%), 11(28%) and 9(23%) of the isolates were resistant to nitrofurantoin, imipenem, gentamicin, cefepime and aztreonam respectively. All the isolates had the ability to form biofilm and 11 (28%) of them were strong biofilm formers. They all (100%) harboured the pslA and pslD biofilm encoding genes. Varied relationships between biofilm formation and resistance to ciprofloxacin, ofloxacin, cefixime, gentamicin, imipenem, and aztreonam were observed. Only 23(59%) of the Pseudomonas isolates phenotypically exhibited efflux pump activity but mexA gene was detected in all 39 (100%) isolates while mexB and oprM genes were detected in 91%, 92%, and 88% of strong, moderate and weak biofilm formers respectively.

Conclusion

Multidrug resistance, biofilm and efflux pump capabilities in Pseudomonas aeruginosa have serious public health implications in the management of infections caused by this organism.

Country Income Is Only One of the Tiles: The Global Journey of Antimicrobial Resistance among Humans, Animals, and Environment

Antimicrobial resistance (AMR) is one of the most complex global health challenges today: decades of overuse and misuse in human medicine, animal health, agriculture, and dispersion into the environment have produced the dire consequence of infections to become progressively untreatable. Infection control and prevention (IPC) procedures, the reduction of overuse, and the misuse of antimicrobials in human and veterinary medicine are the cornerstones required to prevent the spreading of resistant bacteria. Purified drinking water and strongly improved sanitation even in remote areas would prevent the pollution from inadequate treatment of industrial, residential, and farm waste, as all these situations are expanding the resistome in the environment. The One Health concept addresses the interconnected relationships between human, animal, and environmental health as a whole: several countries and international agencies have now included a One Health Approach within their action plans to address AMR. Improved antimicrobial usage, coupled with regulation and policy, as well as integrated surveillance, infection control and prevention, along with antimicrobial stewardship, sanitation, and animal husbandry should all be integrated parts of any new action plan targeted to tackle AMR on the Earth. Since AMR is found in bacteria from humans, animals, and in the environment, we briefly summarize herein the current concepts of One Health as a global challenge to enable the continued use of antibiotics.