Multidrug-resistant Pathogens Research Articles

Urosepsis 30-day mortality, morbidity, and their risk factors: SERPENS study, a prospective, observational multi-center study

PurposeTo provide a descriptive report of mortality and morbidity in the first 30 days of diagnosis of urosepsis. Secondary aim is to identify risk factors of unfavourable outcomes.MethodsProspective observational multicentre cohort study conducted from September 2014 to November 2018 in European hospitals. Adult patients (≥ 18 years) diagnosed with acute urosepsis according to Sepsis-2 criteria with confirmed microbiological infection were included. Outcomes were classified in one of four health states: death, multiple organ failure, single organ failure, and recovery at day 30 from onset of urosepsis. Descriptive statistics and ordinal logistic regression analysis was performed.ResultsThree hundred and fifty four patients were recruited, and 30-day mortality rate was 2.8%, rising to 4.6% for severe sepsis. All patients who died had a SOFA score of ≥ 2 at diagnosis. Upon initial diagnosis, 79% (n = 281) of patients presented with OF. Within 30 days, an additional 5% developed OF, resulting in a total of 84% affected. Charlson score (OR 1.14 CI 1.01–1.28), patients with respiratory failure at baseline (OR 2.35, CI 1.32–4.21), ICU admission within the past 12 months (OR 2.05, CI 1.00–4.19), obstruction causative of urosepsis (OR 1.76, CI 1.02–3.05), urosepsis with multi-drug-resistant(MDR) pathogens (OR 2.01, CI 1.15–3.53), and SOFA baseline score ≥ 2 (OR 2.74, CI 1.49–5.07) are significantly associated with day 30 outcomes (OF and death).ConclusionsImpact of comorbidities and MDR pathogens on outcomes highlights the existence of a distinct group of patients who are prone to mortality and morbidity. These findings underscore the need for the development of pragmatic classifications to better assess the severity of UTIs and guide management strategies.Study registration: Clinicaltrials.gov registration number NCT02380170.

Identification of Potential Therapeutics of Mentha Essential Oil Content as Antibacterial MDR Agents against AcrAB-TolC Multidrug Efflux Pump from Escherichia coli: An In Silico Exploration

Multidrug-resistant bacterial pathogens, such as E. coli, represent a major human health threat. Due to the critical need to overcome this dilemma, since the drug efflux pump has a vital function in the evolution of antimicrobial resistance in bacteria, we have investigated the potential of Mentha essential oil major constituents (1–19) as antimicrobial agents via their ability to inhibit pathogenic DNA gyrase and, in addition, their potential inhibition of the E. coli AcrB-TolC efflux pump, a potential target to inhibit MDR pathogens. The ligand docking approach was conducted to analyze the binding interactions of Mentha EO constituents with the target receptors. The obtained results proved their antimicrobial activity through the inhibition of DNA gyrase (1kzn) with binding affinity ΔG values between −4.94 and −6.49 kcal/mol. Moreover, Mentha EO constituents demonstrated their activity against MDR E. coli by their ability to inhibit AcrB-TolC (4dx7) with ΔG values ranging between −4.69 and −6.39 kcal/mol. The antimicrobial and MDR activity of Mentha EOs was supported via hydrogen bonding and hydrophobic interactions with the key amino acid residues at the binding site of the active pocket of the targeted receptors.

The Prevalence of Antibiotic Resistance Phenotypes and Genotypes in Multidrug-Resistant Bacterial Isolates from the Academic Hospital of Jaén, Spain

The heterogenicity of antimicrobial resistance genes described in clinically significant bacterial isolates and their potential role in reducing the efficacy of classically effective antibiotics pose a major challenge for global healthcare, especially in infections caused by Gram-negative bacteria. We analyzed 112 multidrug-resistant (MDR) isolates from clinical samples in order to detect high resistance profiles, both phenotypically and genotypically, among four Gram-negative genera (Acinetobacter, Escherichia, Klebsiella, and Pseudomonas). We found that 9.8% of the total selected isolates were classified as extensively drug-resistant (XDR) (six isolates identified as A. baumannii and five among P. pneumoniae isolates). All other isolates were classified as MDR. Almost 100% of the isolates showed positive results for blaOXA-23 and blaNDM-1 genes among the A. baumannii samples, one resistance gene (blaCTX-M) among E. coli, and two genetic determinants (blaCTX-M and aac(6′)-Ib) among Klebsiella. In contrast, P. aeruginosa showed just one high-frequency antibiotic resistance gene (dfrA), which was present in 68.42% of the isolates studied. We also describe positive associations between ampicillin and cefotaxime resistance in A. baumannii and the presence of blaVEB and blaGES genes, as well as between the aztreonam resistance phenotype and the presence of blaGES gene in E. coli. These data may be useful in achieving a better control of infection strategies and antibiotic management in clinical scenarios where these multidrug-resistant Gram-negative pathogens cause higher morbidity and mortality.

Bacteriologically Derived Copper Nanoparticles as Novel Arsenal Against Multidrug-Resistant Pathogens

Bacteriologically Derived Copper Nanoparticles as Novel Arsenal Against Multidrug-Resistant Pathogens

Bacterial metallothionein, PmtA, a novel stress protein found on the bacterial surface of Pseudomonas aeruginosa and involved in management of oxidative stress and phagocytosis.

The pathogen Pseudomonas aeruginosa is a highly problematic multidrug-resistant (MDR) pathogen with complex virulence networks. MDR P. aeruginosa infections have been associated with increased clinical visits, very poor healthcare outcomes, and these infections are ranked as critical on priority lists of both the Centers for Disease Control and Prevention and the World Health Organization. Known P. aeruginosa virulence factors have been extensively studied and are implicated in counteracting host defenses, causing direct damage to the host tissues, and increased microbial competitiveness. Targeting virulence factors has emerged as a new line of defense in the battle against MDR P. aeruginosa strains. Bacterial metallothionein is a newly recognized virulence factor that enables evasion of the host immune response. The studies described here identify mechanisms in which bacterial metallothionein (PmtA) plays a part in P. aeruginosa pathogenicity and identifies PmtA as a potential therapeutic target.

Novel Providencia xianensis sp. nov.: A multidrug-resistant species identified in clinical infections.

Providenciagenus is known to harbor certain opportunistic pathogens capable of causinghuman infections. Here, we report two strains of multidrug-resistant bacteria initially identified asProvidencia rettgeriby mass spectrometry, but genome analysis revealed their ANI (79.84-84.20%) and dDDH (21.1-25.6%) values to fall below the accepted species threshold forknown Providencia species. We therefore propose that these isolates be recognized as a novelspecies,Providencia xianensissp. nov. Alarmingly, both strains, isolated from locations far apart, exhibited resistance to last-resort antibiotics, indicating their possible wide distribution, underscoring the urgency for immediate attention and enhanced surveillance for this emerging multidrug-resistant pathogen.

Metagenomic nanopore sequencing for exploring the nature of antimicrobial metabolites of Bacillus haynesii

Multidrug-resistant (MDR) pathogens are a rising global health worry that imposes an urgent need for the discovery of novel antibiotics particularly those of natural origin. In this context, we aimed to use the metagenomic nanopore sequence analysis of soil microbiota coupled with the conventional phenotypic screening and genomic analysis for identifying the antimicrobial metabolites produced by promising soil isolate(s). In this study, whole metagenome analysis of the soil sample(s) was performed using MinION™ (Oxford Nanopore Technologies). Aligning and analysis of sequences for probable secondary metabolite gene clusters were extracted and analyzed using the antiSMASH version 2 and DeepBGC. Results of the metagenomic analysis showed the most abundant taxa were Bifidobacterium, Burkholderia, and Nocardiaceae (99.21%, followed by Sphingomonadaceae (82.03%) and B. haynesii (34%). Phenotypic screening of the respective soil samples has resulted in a promising Bacillus isolate that exhibited broad-spectrum antibacterial activities against various MDR pathogens. It was identified using microscopical, cultural, and molecular methods as Bacillus (B.) haynesii isolate MZ922052. The secondary metabolite gene analysis revealed the conservation of seven biosynthetic gene clusters of antibacterial metabolites namely, siderophore lichenicidin VK21-A1/A2 (95% identity), lichenysin (100%), fengycin (53%), terpenes (100%), bacteriocin (100%), Lasso peptide (95%) and bacillibactin (53%). In conclusion, metagenomic nanopore sequence analysis of soil samples coupled with conventional screening helped identify B. haynesii isolate MZ922052 harboring seven biosynthetic gene clusters of promising antimicrobial metabolites. This is the first report for identifying the bacteriocin, lichenysin, and fengycin biosynthetic gene clusters in B. haynesii MZ922052.

Back to the Future: Intravenous Fosfomycin is Safe and Effective for the Treatment of Complicated Infections in Children.

Despite its broad spectrum and excellent safety profile, fosfomycin is still rarely used in pediatrics, with very limited experience from clinicians. We retrospectively reviewed the medical records of all children admitted to Bambino Gesù Children's Hospital, IRCCS, Rome, Italy, and treated with fosfomycin for any serious infection. Children with immunodeficiency and oncologic diseases were excluded. Of each, we reported and analyzed demographic and clinical data. The clinical charts of 20 patients were reviewed and analyzed. The mean age was 10.2 years. Most children were males (85%). Most patients treated had an osteo-articular infection (65%). In our sample, 7 patients (35%) had an underlying comorbidity. The causative agent was isolated in 14 cases (70%). All patients were treated with a combination of 2-3 antibiotics, including fosfomycin. The average duration of antibiotic treatment was 18 days. After treatment, 8 patients (40%) experienced a mild adverse reaction, possibly correlated with the administration of fosfomycin. All patients were discharged in good clinical condition. The present study reports on a sample of pediatric patients with complicated infections where administration of fosfomycin led to eradication of the disease with little or no side effects. Role of the underlying condition and concomitant medication in causing the reaction could not be ruled out. These data suggest that fosfomycin is an effective and safe antibiotic in the pediatric population, particularly for deep-seated infections sustained by multi-drug resistant pathogens.

In-vitro antibacterial activity of Zingiber officinale (ginger) against bacteria isolated from reproductive tract of clinical endometritic Murrah buffaloes

Endometritis, an inflammation of the innermost uterine layer, is caused by a variety of bacteria, including Gram- positive and Gram-negative aerobes and anaerobes. This study aimed to identify the active compounds in Zingiber officinale (ginger) and assess its effectiveness against common bacterial pathogens found in Murrah buffaloes suffering from endometritis. The infrared spectrum of ginger powder displayed a range of wavelengths from 3361.89/cm to 664.26/cm, indicating the presence of eight functional groups. In the hydro-ethanolic ginger extract, the spectrum ranged from 3402.8/cm to 765.35/cm, revealing 12 functional groups. A total of 42 vaginal mucus samples were collected, with E. coli being the most prevalent in 23 samples, followed by S. aureus in 21 samples, Pseudomonas spp. in 12 samples, and Campylobacter spp. in 11 samples. To evaluate the in vitro antibacterial activity of ginger extracts, antimicrobial susceptibility tests were conducted at concentrations of 2.5, 5, 10, 20, 30, 40, and 50 mg/ml. Staphylococcus aureus exhibited the highest sensitivity to the ginger extract, while E. coli showed substantial resistance. In conclusion, ginger demonstrates potent antibacterial activity against multidrug-resistant uterine pathogens and could serve as an alternative therapy to mitigate the risk of drug resistance in treating uterine infections.

A Comprehensive Study on Peppermint Oil and Cinnamon Oil as Nanoemulsion: Preparation, Stability, Cytotoxicity, Antimicrobial, Antifungal, and Antioxidant Activity.

Recent studies have shown that nanoemulsions prepared with essential oils have significant antimicrobial potential against multidrug-resistant pathogens due to increased chemical stability. Nanoemulsion also promotes controlled and sustained release, which increases their bioavailability and efficacy against multidrug-resistant bacteria. This study aimed to investigate the antimicrobial, antifungal, antioxidant, and cytotoxicity properties of cinnamon essential oil and peppermint essential oil as nanoemulsions compared to pure forms. For this purpose, analyses of the selected stable nanoemulsions were carried out. The droplet sizes and zeta potentials of peppermint essential oil nanoemulsions and cinnamon essential oil nanoemulsions were found to be 154.6±1.42 nm and -17.1±0.68 mV and 200.3±4.71 nm and -20.0±0.81 mV, respectively. Although the amount of essential oil used in nanoemulsions was 25% w/w, antioxidant and antimicrobial activities were found to be more effective compared to pure essential oils. In cytotoxicity studies on the 3T3 cell line, both essential oil nanoemulsions showed higher cell viability than pure essential oils. At the same time, cinnamon essential oil nanoemulsions exhibited a higher antioxidant property than peppermint essential oil nanoemulsions and showed superiority in the antimicrobial susceptibility test conducted against four bacteria and two fungi. Cell viability tests determined that cinnamon essential oil nanoemulsions showed considerably higher cell viability compared to pure cinnamon essential oil. These findings indicated that the prepared nanoemulsions in the current study might positively influence the dosing regimen and clinical outcomes of antibiotic therapy.

Clinical characteristics and risk factors for bacterial co-infections in COVID-19 patients: A retrospective study

ObjectiveThis study aimed to analyze the bacterial composition, distribution, drug sensitivity, and clinical characteristics of COVID-19 patients who develop bacterial co-infections. MethodsWe conducted a retrospective study of 184 COVID-19 patients admitted between December 2022 and January 2023. Data on gender, age, length of hospital stay, pneumonia classification, underlying diseases, invasive surgery, hormone therapy, inflammation indicators, and other relevant information were collected. Samples of sputum, bronchoscopy sputum, alveolar lavage fluid, middle urine, puncture fluid, wound secretions, and blood were collected for pathogen isolation, identification, and drug sensitivity testing. ResultsThe majority of COVID-19 patients with bacterial co-infection were elderly and had underlying diseases. Invasive surgery and hormone therapy were identified as risk factors for co-infections. Laboratory analysis showed reduced lymphocyte count and elevated levels of CRP and PCT. The most common pathogens in co-infections were S. aureus, E. coli, K. pneumoniae, A. baumannii, and P. aeruginosa. The detection rate of drug-resistant strains, including MRSA, CRKP, CRAB, CRPA, and CRECO, increased with the severity of pneumonia. ConclusionRespiratory tract infections were the most common site of bacterial co-infection in COVID-19 patients. Severe cases were more susceptible to multidrug-resistant pathogens, leading to a higher mortality rate. Timely control and prevention of co-infection are crucial for improving the prognosis of COVID-19 patients.

Biogenic Synthesis of Selenium and Copper Oxide Nanoparticles and Inhibitory Effect against Multi-Drug Resistant Biofilm-Forming Bacterial Pathogens

Antimicrobial resistance (AMR), caused by microbial infections, has become a major contributor to morbid rates of mortality worldwide and a serious threat to public health. The exponential increase in resistant pathogen strains including Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) poses significant hurdles in the health sector due to their greater resistance to traditional treatments and medicines. Efforts to tackle infectious diseases caused by resistant microbes have prompted the development of novel antibacterial agents. Herein, we present selenium and copper oxide monometallic nanoparticles (Se-MMNPs and CuO-MMNPs), characterized using various techniques and evaluated for their antibacterial potential via disc diffusion, determination of minimum inhibitory concentration (MIC), antibiofilm, and killing kinetic action. Dynamic light scattering (DLS), scanning electron microscopy (SEM/EDX), and X-ray diffraction (XRD) techniques confirmed the size-distribution, spherical-shape, stability, elemental composition, and structural aspects of the synthesized nanoparticles. The MIC values of Se-MMNPs and CuO-MMNPs against S. aureus and E. coli were determined to be 125 μg/mL and 100 μg/mL, respectively. Time–kill kinetics studies revealed that CuO-MMNPs efficiently mitigate the growth of S. aureus and E. coli within 3 and 3.5 h while Se-MMNPs took 4 and 5 h, respectively. Moreover, CuO-MMNPs demonstrated better inhibition compared to Se-MMNPs. Overall, the proposed materials exhibited promising antibacterial activity against S. aureus and E. coli pathogens.

Staphylococcus aureus Isolated From Traditional Artisanal Raw Milk Cheese from Southern Brazil: Diversity, Virulence, and Antimicrobial Resistance Profile

Staphylococcus aureus is one of the primary pathogenic agents found in cheeses produced with raw milk. Some strains of S. aureus are enterotoxigenic, possessing the ability to produce toxins responsible for staphylococcal food poisoning when present in contaminated foods. This study aimed to genotypically characterize, assess the antimicrobial resistance profile, and examine the enterotoxigenic potential of strains of S. aureus isolated from artisanal colonial cheese. Additionally, a bacterial diversity assessment in the cheeses was conducted by sequencing the 16S rRNA gene. The metataxomic profile revealed the presence of 68 distinct species in the cheese samples. Fifty-seven isolates of S. aureus were identified, with highlighted resistance to penicillin in 33% of the isolates, followed by clindamycin (28%), erythromycin (26%), and tetracycline (23%). The evaluated strains also exhibited inducible resistance to clindamycin, with nine isolates considered multidrug-resistant (MDR). The agr type I was the most prevalent (62%) among the isolates, followed by agr type II (24%). Additionally, ten spa types were identified. Although no enterotoxins and their associated genes were detected in the samples and isolates, respectively, the Panton-Valentine leukocidin gene (lukS-lukF) was found in 39% of the isolates. The presence of MDR pathogens in the artisanal raw milk cheese production chain underscores the need for quality management to prevent the contamination and dissemination of S. aureus strains.

A small step towards an important goal: fragment screen of the c-di-AMP-synthesizing enzyme CdaA.

CdaA is the most widespread diadenylate cyclase in many bacterial species, including several multidrug-resistant human pathogens. The enzymatic product of CdaA, cyclic di-AMP, is a secondary messenger that is essential for the viability of many bacteria. Its absence in humans makes CdaA a very promising and attractive target for the development of new antibiotics. Here, the structural results are presented of a crystallographic fragment screen against CdaA from Listeria monocytogenes, a saprophytic Gram-positive bacterium and an opportunistic food-borne pathogen that can cause listeriosis in humans and animals. Two of the eight fragment molecules reported here were localized in the highly conserved ATP-binding site. These fragments could serve as potential starting points for the development of antibiotics against several CdaA-dependent bacterial species.

Pontederia crassipes Biosynthesised Silver Nanoparticles (AgNPs), Characterisation and Activity against Multidrug-Resistant Microbes

Introduction: Pontederia crassipes (water hyacinth) has been singled out as one of the major causes of enormous economic and ecological losses to tropical water systems and habitats. Almost impossible to eradicate, the ominous species is characterized by rapid multiplication, giving rapid and extensive spread that can choke entire rivers and water bodies. However, vast, diverse bioactive secondary metabolites are found in P crassipes which exhibit an expansive assortment of antibacterial properties used in traditional medicine. The rapid emergence of Multi Drug Resistant (MDR) pathogens to common drugs is a pandemic of global proportions. Global health institutions are calling for a coordinated, global action plan to develop new biomaterials to combat the rising threat by MDR strains and improve treatment outcomes and save lives. This study proposes consumption of the water hyacinth lily species through a novel, material biosynthesis approach not only to manage the aquatic infestation but to develop advanced multifunctional, anti-microbial Silver nanoparticles through bio-reduction and capping of Silver salts targeted at MDR microbes. Methodology: After screening for active phytoconstituents of P.crassipes. The Biosynthesis of Novel AgNPs mediated by phenolic, antibacterial lyophilized hydro-ethanolic extracts from P crassipes as both bioreduction and capping agents was investigated. The resultant AgNPs characteristics, toxicological profiles and the antibacterial effects on 10 common microbes including MDR bacterial strains were evaluated. Observations and Results: TEM revealed that cubic and spherical nanometric AgNPs structures were successfully synthesized with particle size range from 10-60nm. With an average zone of inhibition of 29mm and an MIC of 6.25 µg/ml .The nanoparticles were efficacious against selected MDR strains and common infectious bacterial strains tested. In-vivo acute oral toxicity evaluations confirmed the safety of P crassipes. Conclusion: Biogenic P.crassipes mediated AgNPs are feasible, safe and efficacious and have immense potential for optimization into efficient broad spectrum MDR antibacterial agents.b

Neonatal Sepsis Due to Multidrug-resistant Bacteria at a Tertiary Teaching Hospital in Ethiopia.

The burden of multidrug-resistant bacterial infections in low-income countries is alarming. This study aimed to identify the bacterial etiologies and antibiotic resistance patterns among neonates in Jimma, Ethiopia. An observational longitudinal study was conducted among 238 presumptive neonatal sepsis cases tested with blood and/or cerebrospinal fluid culture. The bacterial etiologies were confirmed using matrix-assisted laser desorption ionization-time of flight mass spectrometry. The antibiotic resistance patterns were determined using the automated disc diffusion method (Bio-Rad) and the results were interpreted based on the European Committee on Antimicrobial Susceptibility Testing 2021 breakpoints. Extended-spectrum β-lactamases were detected using a double disc synergy test and confirmed by Mast discs (Mast Diagnostica GmbH). A total of 152 pathogens were identified. Of these, Staphylococcus aureus (18.4%) was the predominant isolate followed by Klebsiella pneumoniae (15.1%) and Escherichia coli (10.5%). All the isolates exhibited a high rate of resistance to first- and second-line antibiotics ranging from 73.3% for gentamicin to 93.3% for ampicillin. Furthermore, 74.4% of the Gram-negative isolates were extended-spectrum β-lactamase producers and 57.1% of S. aureus strains were methicillin resistant. The case fatality rate was 10.1% and 66.7% of the deaths were attributable to infections by multidrug-resistant pathogens. The study revealed a high rate of infections with multidrug-resistant pathogens. This poses a significant challenge to the current global and national target to reduce neonatal mortality rates. To address these challenges, it is important to employ robust infection prevention practices and continuous antibiotic resistance testing to allow targeted therapy.

Antimicrobial activity of cell-free supernatant derived from Ligilactobacillus animalis SWLA-1 in a novel ex vivo canine corneal infection model.

Canine bacterial keratitis is a corneal infection that causes various symptoms, including visual impairment, and necessitates eye removal in severe cases. Staphylococcus pseudintermedius is a pathogen that causes significant bacterial keratitis in canine patients. Moreover, multi-drug resistant Staphylococcus pseudintermedius (MDRSP) has been reported in both humans and animals. Regarding treatment failure against multi-drug resistant (MDR) pathogens with classic antibiotics, antimicrobial compounds derived from probiotics have been suggested as an alternative approach. Ligilactobacillus animalis SWLA-1 strain and its cell-free supernatant (CFS) have previously demonstrated potent antimicrobial activity against various MDR pathogenic bacteria. Based on this finding, we evaluated the anti-staphylococcal activity of CFS derived from Ligilactobacillus animalis SWLA-1 against MDRSP in a newly established ex vivo canine corneal infection model using fresh canine corneoscleral rims. Additionally, an in vitro cytotoxicity test using human keratocytes was performed. CFS significantly inhibited the growth of MDRSP in the novel ex vivo model and did not exhibit any significant toxicity against keratocytes in vitro. Based on these results, the antimicrobial compounds in CFS show potential as a novel approach for MDR staphylococcal keratitis treatment.

Characterization of biofilm formation and multi-drug resistance among Pseudomonas aeruginosa isolated from hospital wastewater in Dhaka, Bangladesh

ABSTRACT Hospital wastewater has been identified as a hotspot for the emergence and transmission of multidrug-resistant (MDR) pathogens that present a serious threat to public health. Therefore, we investigated the current status of antibiotic resistance as well as the phenotypic and genotypic basis of biofilm formation in Pseudomonas aeruginosa from hospital wastewater in Dhaka, Bangladesh. The disc diffusion method and the crystal violet assay were performed to characterize antimicrobial resistance and biofilm formation, respectively. Biofilm and integron-associated genes were amplified by the polymerase chain reaction. Isolates exhibited varying degrees of resistance to different antibiotics, in which >80% of isolates showed sensitivity to meropenem, amikacin, and gentamicin. The results indicated that 93.82% of isolates were MDR and 71 out of 76 MDR isolates showed biofilm formation activities. We observed the high prevalence of biofilm-related genes, in which algD+pelF+pslD+ (82.7%) was found to be the prevalent biofilm genotypic pattern. Sixteen isolates (19.75%) possessed class 1 integron (int1) genes. However, statistical analysis revealed no significant association between biofilm formation and multidrug resistance (χ2 = 0.35, P = 0.55). Taken together, hospital wastewater in Dhaka city may act as a reservoir for MDR and biofilm-forming P. aeruginosa, and therefore, the adequate treatment of wastewater is recommended to reduce the occurrence of outbreaks.

Camel Milk Resistome in Kuwait: Genotypic and Phenotypic Characterization

Antimicrobial resistance (AMR) is one of the major global health and economic threats. There is growing concern about the emergence of AMR in food and the possibility of transmission of microorganisms possessing antibiotic resistance genes (ARGs) to the human gut microbiome. Shotgun sequencing and in vitro antimicrobial susceptibility testing were used in this study to provide a detailed characterization of the antibiotic resistance profile of bacteria and their ARGs in dromedary camel milk. Eight pooled camel milk samples, representative of multiple camels distributed in the Kuwait desert, were collected from retail stores and analyzed. The genotypic analysis showed the presence of ARGs that mediate resistance to 18 classes of antibiotics in camel milk, with the highest resistance to fluoroquinolones (12.48%) and disinfecting agents and antiseptics (9%). Furthermore, the results pointed out the possible transmission of the ARGs to other bacteria through mobile genetic elements. The in vitro antimicrobial susceptibility testing indicated that 80% of the isolates were resistant to different classes of antibiotics, with the highest resistance observed against three antibiotic classes: penicillin, tetracyclines, and carbapenems. Multidrug-resistant pathogens including Klebsiella pneumoniae, Escherichia coli, and Enterobacter hormaechei were also revealed. These findings emphasize the human health risks related to the handling and consumption of raw camel milk and highlight the necessity of improving the hygienic practices of farms and retail stores to control the prevalence of ARGs and their transmission.

Application of Mono and Trinuclear Cyclometalated Iridium (III) Complexes in Differential Bacterial Imaging and Antimicrobial Photodynamic therapy.

The application of transition metal complexes for antimicrobial photodynamic therapy (PDT) has emerged as an attractive alternative in mitigating a broad range of bacterial pathogens, including multidrug-resistant pathogens. In view of their photostability, long excited-state lifetimes, and tunable emission properties, transition metal complexes also contribute as bioimaging agents. In the present work, we designed mono and trinuclear cyclometalated iridium(III) complexes to explore their imaging application and antibacterial potential. For this, we used Methicillin-resistant S. aureus (MRSA), the most prevalent of community-associated (CA) multidrug-resistant (MDR) bacteria (CA MDR) and Lactococcus lactis (L. lactis) as Gram-positive while Campylobacter jejuni (C. jejuni) and E. coli as Gram-negative bacteria. In addition to differential bioimaging of these bacteria, we assessed the antibacterial effects of both mono and trinuclear Ir(III) complexes under exposure to 427 nm LED light. The data presented herein strongly suggest better efficacy of trinuclear Ir(III) complex over mononuclear complex in imparting photoinduced cell death of MRSA. Based on the safety profile of these complexes, we propose that trinuclear cyclometalated iridium(III) complex hold great promise for selective recognition and targeting MDR bacteria with minimal off-target effect.