Gram-negative Species Research Articles

Bacterial profile and antimicrobial susceptibility patterns of common neonatal sepsis pathogens in Gulf Cooperation Council countries: A systematic review and meta-analysis

Introduction: Neonatal sepsis (NS) is a major healthcare burden in Gulf Cooperation Council (GCC) countries, with a prevalence higher than the global average. Microbial drug resistance has major implications for mortality and morbidity from NS. Objective: To synthesize data regarding the patterns of causative bacteria of NS in the GCC and their antimicrobial susceptibility profiles. Methods: Following the exploration of four electronic databases, i.e., EBSCOhost, ProQuest, PubMed/MEDLINE, and ScienceDirect, eligible studies were identified (i.e., published between 2013 and 2023 and reported bacterial profile and/or antimicrobial susceptibility patterns). The outcomes included the pooled prevalence of bacteria and their susceptibility patterns. Proportion meta-analysis was performed for each outcome of interest. Results: Fifteen studies were eligible (total positive cases = 2,473). Coagulase-negative Staphylococci (CoNS) (28.1%) were the most common gram-positive causative pathogen, followed by group B Streptococcus (GBS) (16.2%) and Staphylococcus aureus (9.9%); for gram-negative, Escherichia coli (12.7%) and Klebsiella species (11.4%) were most common. The susceptibility rates of these bacteria to first-line antibiotics were high; gram-positive bacteria had the highest susceptibility to ampicillin (72.8–98%), and gram-negative bacteria was most susceptible to amikacin (94.6–98%). Additionally, both gram-positive (67–77%) and negative (87–93%) bacteria exhibited high susceptibility to gentamicin. Conclusion: The most common pathogens among NS patients were gram-positive. The pathogens, irrespective of stain test, were susceptible to the current antibiotic therapy. We recommend the judicious use of empirical antibiotic therapy to prevent the growing risk of antimicrobial resistance.

Chemical Composition, Biological Activity, and Application of Rosa damascena Essential Oil as an Antimicrobial Agent in Minimally Processed Eggplant Inoculated with Salmonella enterica

Rosa damascena is mostly grown for its usage in the food, medical, and perfume industries, while it is also used as an attractive plant in parks, gardens, and homes. The use of R. damascena essential oil may yield new results in relation to the antimicrobial activity of essential oils and their use mainly in extending the shelf life of foods. This study investigates the chemical composition and antimicrobial properties of Rosa damascena essential oil (RDEO) using gas chromatography–mass spectrometry (GC-MS) and various bioassays to explore its potential applications in food preservation and microorganism growth control. The GC-MS analysis revealed that RDEO is predominantly composed of phenylethyl alcohol (70%), which is known for its antimicrobial and aromatic properties. Additionally, other significant constituents were identified, including nerol, citronellol, and geraniol, which may contribute to the EOs overall bioactivity. The antimicrobial activity was assessed through the minimal inhibition concentration against five Candida yeast strains, four Gram-positive, and four Gram-negative bacteria, including biofilm-forming Salmonella enterica. Determination of minimum inhibitory concentrations (MIC) revealed the strongest effects of RDEO’s on Gram-negative species, with MIC50 values as low as 0.250 mg/mL for S. enterica. Moreover, an in situ assessment utilizing fruit and vegetable models demonstrated that the vapor phase of RDEO significantly suppressed microbial growth, with the most substantial reductions observed on kiwi and banana models. As a result of our study, the antimicrobial effect of RDEO on the microbiota of sous vide processed eggplant was detected, as well as an inhibitory effect on S. enterica during storage. The insecticidal activity against Megabruchidius dorsalis Fahreus, 1839, was also studied in this work and the best insecticidal activity was found at the highest concentrations. These results suggest that RDEO has the potential to serve as a natural antimicrobial agent in food preservation and safety applications, providing an alternative to synthetic preservatives.

Antimicrobial, Antifungal, and Insecticidal Activities of Scolymus Grandiflorus Essential Oil Rich in Davanoid Compounds

Background: This study explores the antimicrobial, antifungal, and insecticidal properties of Scolymus grandiflorus essential oil, examining its potential uses in the fields of pharmacology and agriculture. Materials and Methods: The essential oil obtained by hydrodistillation was studied by GC and GC/MS. The antibacterial capacity of the essential oil was determined against two Gram-positive and three Gram-negative bacterial species. The antifungal activity of the essential oil was investigated against two fungi responsible for many fruit and vegetable diseases. The insecticidal activity of essential oil was evaluated against larvae, pupae, and adult flies of Ceratitis capitata. Results: The GC and GC-MS analysis of the essential oil of the roots of S. grandiflorus revealed the predominant presence of davanoids, representing more than 80% of its chemical composition. The results of the disc diffusion test showed significant antimicrobial activity. The essential oil inhibited the growth of Salmonella typhi (25 mm), Staphylocoque aureus (18 mm), and Escherichia coli (17 mm), with inhibition diameters comparable to those of gentamicin. The essential oil significantly inhibited mycelial growth, with up to 98% inhibition for Fusarium solani and 73% for Alternaria alternata at 8 μL/mL. Insecticidal activity was most pronounced on adult flies, followed by pupae and finally larvae. Conclusion: Tests on the essential oils of S. grandiflorus revealed promising characteristics as insecticidal, antifungal, and antimicrobial agents. These results could be used in the development of new solutions to control pathogens responsible for plant diseases and mycotoxin-producing organisms.

Thanatin and vinyl sulfide analogues as narrow spectrum antimicrobial peptides that synergise with polymyxin B

Thanatin is a β-hairpin antimicrobial peptide cyclised by a single disulfide bond that has shown potent broad-spectrum activity towards bacterial and fungal pathogens. Towards Gram-negative species, thanatin acts both by forming trans-membranal pores and inhibiting outer membrane biogenesis by binding to LptA and blocking lipopolysaccharide (LPS) transport. Inspired by previous modifications of thanatin, an analogue was prepared which demonstrated potent but selective activity towards E. coli. Furthermore, this compound was shown to act in synergy with the highly potent FDA-approved lipopeptide antibiotic polymyxin B, which engages LPS at the cytoplasmic membrane. Four analogues of thanatin in which the disulfide was substituted for vinyl sulfide bridge mimetics were prepared, all of which retained similar secondary structures. Two of these retained substantial potency and selectivity towards E. coli. Importantly, synergy with polymyxin B was also maintained for the lead analogue. The vinyl sulfide potentially offers a facile replacement strategy for labile disulfide bonds and the selective activity and drug synergy of the reported thanatin analogues is promising for the development of narrow spectrum antimicrobials with reduced likelihood of resistance emerging in clinical settings.

Bacterial Co-Infections and Antibiotic Resistance in Urinary Tract Infection of Covid-19 Patients in Erbil City

The COVID-19 pandemic has raised concerns over secondary infections because it has limited treatment options and empiric antimicrobial treatment poses serious risks of aggravating antimicrobial resistance. Many studies have shown that COVID-19 patients are predisposed to developing secondary infections. The prevalence of urinary tract infections (UTI) was evaluated in 248 patients admitted to different hospitals in Erbil city, Iraq. Results showed 138 (55.65%) patients were positive for bacterial growth, of which 72 isolates of Gram-negative and 66 isolates of Gram-positive bacteria were isolated and identified from the urine of COVID-19 patients depending on the 16S rRNA gene using PCR. The predominant obtained bacteria were Staphylococci species, of which isolates belong to 6 species, and the predominant Gram-negative species was Pseudomonas spp. which belongs to 4 species. Also, their susceptibility to 15 antibiotics was tested and it was found that most of the Gram-negative isolates were highly resistant to ampicillin 66(91.66%), amoxicillin 60(83.33%), cephalexin 52(72.22%) and cefixime 50(69.44%). While the most effective antibiotic was imipenem, and with percentage of 26(36.11%), it also showed variable sensitivity to other antibiotics. For Gram-positive bacteria, the highest resistance was against cefixime 40(60.60%), ampicillin 28(42.42%), and 18(27.27%) for both amoxicillin and ciprofloxacin, while the most effective antibiotic was gentamicin, which showed effectiveness against all the Gram-positive isolates. Another part of the study concerned with detection of the existence of ESBLs genes responsible for antibiotic resistance. The results revealed that all the isolates possessed the 16S rRNA gene, whereas blaTEM and blaCTX-M were found to be the most possessed genes in all the isolates, with a percentage of (88.33%).

A recent update on the antibacterial effects ofdistinct bioactive molecules derived from theCannabis plant.

The number of human infections with multidrug-resistant (MDR) bacteria is increasing worldwide and constitutes a serious threat to human health. Given the lack of novel antibiotic compounds worsening this dilemma, alternative antibiotic-independent treatment and prevention strategies of infectious diseases applying natural compounds appear highly appreciable. Given the long-known health-beneficial and disease-alleviating properties of Cannabis, we performed a literature search summarizing current knowledge regarding the antibacterial effects of extracts from different parts of the Cannabis sativa plant and of defined Cannabis-derived molecules and their potential mode of action. Theincluded studies revealed that various extracts and essential oils of C. sativa as well as major cannabinoids exerted potent activities against a broad spectrum of Gram-positive bacteria and against some Gram-negative bacterial species including MDR strains. Particularly the disruption of the bacterial cytoplasmic membrane by some cannabinoids resulted in potent antibacterial effects against Gram-positivebacteria including methicillin-resistant Staphylococcus aureus. Furthermore, defined cannabinoids inhibited the formation of and eradicated existing bacterial biofilms. In conclusion, given their antibacterial properties distinct Cannabis-derived molecules expand the repertoire of antibiotics-independent treatment options in the combat of bacterial infectious diseases which should be further addressed in future studies including clinical trials.

Antimicrobial activity and synergistic effect of carvacrol and thymol against foodborne pathogens

The present study aimed to evaluate the antimicrobial activity and the synergistic effect of the natural compounds carvacrol (CAR) and thymol (THY) against pathogens that cause foodborne illnesses. The antimicrobial activity was assessed through the Antimicrobial Sensitivity Test (AST) using the broth microdilution technique in 96-well plates. The concentration ranges evaluated were from 5000 to 10 µg.mL-1. The tested bacteria included both gram-negative and gram-positive species. The observed minimum inhibitory concentration (MIC) ranges for the components were: CAR (39 - 312 µg.mL-1), THY (39 - 1250 µg.mL-1), and the synergistic effect CAR/THY (20 - 625 µg.mL-1). The minimum bactericidal concentration (MBC) ranges were: CAR (78 - 625 µg.mL-1), THY (78 - 2500 µg.mL-1), and the synergistic effect CAR/THY (39 - 625 µg.mL-1). Enterococcus faecalis (ATCC19433) did not show sensitivity to the isolated or combined antimicrobials (>5000 µg.mL-1). Different strains of Escherichia coli and Listeria monocytogenes displayed distinct levels of sensitivity. The results demonstrated that foodborne pathogens subjected to the test containing the mixture of the two components exhibited greater sensitivity.

Green synthesis of anethole-loaded zinc oxide nanoparticles enhances antibacterial strategies against pathogenic bacteria.

The threat of antibiotic resistance is escalating, diminishing the effectiveness of numerous antibiotics due to the rapid development of resistant bacteria. In response, the use of green-synthesized nanoparticle, alone or combined with antimicrobial agents, appears promising. This study explores the effectiveness of zinc oxide nanoparticles (ZnONPs) synthesized using Loranthus cordifolius leaf extracts and subsequently coated with anethole. The fabrication of these nanoparticles was confirmed via UV-Vis, FTIR and TEM analyses, ensuring the nanoparticles were produced as intended. Utilizing a nanoprecipitation process that excludes evaporation and drying, a high drug loading capacity of 16.59% was accomplished. The encapsulation efficiency for anethole was recorded at 88.23 ± 4.98%. Antibacterial efficacy was assessed by com paring the green-synthesized ZnONPs (average size: 14.47nm), anethole-loaded ZnONPs (average size: 14,75nm), and commercially sourced ZnONPs. The ZnONPs with anethole demonstrated superior inhibition against all tested bacterial strains, including Gram-negative species like Pseudomonas aeruginosa and Escherichia coli, and Gram-positive species like Bacillus subtilis and Staphylococcus aureus, outperforming the commercially available ZnONPs. Additionally, anethole-coated ZnONPs showed the greatest inhibition of Gyr-B activity (IC50 = 0.78 ± 0.2M), better than both green-synthesized and commercially available ZnONPs. These findings emphasize the enhanced antimicrobial properties of ZnONPs, particularly when combined with green synthesis and anethole loading, highlighting their potential in various biomedical applications.

Antimicrobial Activity of Commercial Essential Oils Available in the Market of Kathmandu

Given the increasing global apprehension surrounding antibiotic resistance, there has been growing interest in exploring natural compounds, specifically essential oils, as potential substitutes for combating microbial pathogens. This research work aimed to evaluate the antimicrobial activity exhibited by commercial essential oils and by diluting them with the carrier oils at equal concentration. The screening of antimicrobial activity was conducted using the agar well diffusion method with eight essential oils. Using the broth dilution method, the antibacterial activity of eight commonly used essential oils: lavender, tea tree, eucalyptus, peppermint, thyme, citrus, rosemary, and cinnamon were assessed. Both Gram-positive and Gram-negative species were selected for antimicrobial activity. The minimum inhibitory concentration (MIC) was determined by the broth dilution method. Following MIC determination, a sub-culture was performed on nutrient agar plates to ascertain the minimum bactericidal concentration (MBC). All the antibiotics used in the study demonstrated sensitivity when subjected to the antibiotic susceptibility test. Thyme, cinnamon and peppermint strongly inhibited the growth of S. epidermidis 46 mm, 30mm, and 34 mm respectively. Findings revealed distinct variations in the MIC values among the different essential oils and bacteria tested. Thyme and tea tree oils exhibited the broadest antibacterial spectrum, inhibiting both Gram-positive and Gram-negative bacteria at relatively low concentrations. Thyme (15.625 μl/ml) and tea tree (31.25 μl/ml) oil demonstrated promising activity against Gram-positive pathogen, while tea tree oil (15.625 μl/ml) displayed better efficacy against Gram-negative bacteria. A significant outcome was observed when the essential oils were diluted with carrier oils, indicating promising results in terms of antibacterial activity. These findings highlight the potential of essential oils, particularly thyme and tea tree oils, as effective natural antimicrobial agents.

Characterization of infectious bacterial keratitis in Östergötland County, Sweden: a 10-year retrospective study.

The aim of this study was to characterize bacterial species, aetiology and antibiotic susceptibility connected to bacterial keratitis infections in Östergötland, Sweden. Retrospective cross-sectional study based on electronic health records for the period 2010-2019. Records of patients diagnosed with infectious keratitis were screened for microbiology confirmed infectious bacterial keratitis. Bacterial species and their susceptibility to antibiotics were determined from microbiology test results. One-hundred and ninety patients with lab culture-confirmed infectious bacterial keratitis were included in the analysis. The most frequently found bacterial species were coagulase-negative staphylococci (39%), Staphylococcus aureus (17%) and Cutibacterium acnes (10%). Pseudomonas spp. was the most frequently found Gram-negative bacterial species (7%). Contact lens wear and severely ill/blind eye were the top two aetiologies associated with bacterial keratitis, 22% of the patients with bacterial keratitis were also diagnosed with glaucoma. Most isolates, 157 out of 173, were susceptible to fluoroquinolones, and 145 out of 155 isolates were susceptible to chloramphenicol. Our results revealed a positive rate of bacterial keratitis of 59% for the samples sent to the laboratory. There was a high susceptibility of the bacterial species to the recommended antibiotics. Our results indicate that it is likely that patients are receiving the correct treatment. Future studies are necessary to monitor changes in antibiotic susceptibility.

Tolfenpyrad Derivatives Exhibit Potent Francisella-Specific Antibacterial Activity without Toxicity to Mammalian Cells In Vitro.

Tularemia is a deadly disease caused by Francisella tularensis, an emerging intracellular bacterial pathogen that can be disseminated rapidly through aerosols and vector-borne transmission. Recent surveillance data demonstrate an increasing incidence in several countries. Although clinical isolates of Francisella strains are sensitive to currently used antibiotics, engineered or horizontal acquisition of antibiotic resistance is a constant threat to public health. Therefore, the identification of antibiotics that target previously undrugged pathways is required to safeguard human health. An environmental pesticide that is registered for use in multiple countries, tolfenpyrad, shows promising activity to block Francisella growth; however, it is not a suitable antimicrobial candidate for use in vivo due to potential toxicity in humans and other animals. In this study, we applied a structure-activity relationship approach to tolfenpyrad to generate compounds with improved antibacterial activity and reduced toxicity. Through screening of a library of derivatives, we identified analogs with improved therapeutic windows compared with tolfenpyrad. Although structural diversity exists among these analogs, they inhibit the growth of Francisella species but not other Gram-negative or Gram-positive species. These compounds block intramacrophage growth of F. novicida and pathogenesis in an in vivo arthropod model of infection. Although the biochemical activity of these drugs is unknown, they appear to target the same pathway as the parent molecule because F. novicida mutants that are resistant to tolfenpyrad are also resistant to its analogs. Taken together, these findings suggest that these tolfenpyrad-derived compounds comprise a new class of Francisella-targeted antimicrobials and merit further evaluation and development.

The antimicrobial resistance profile in poultry of Central and Southern India is evolving with distinct features

Antimicrobial resistance (AMR) is fast emerging and is depleting antibiotics repertoire. Poultry is a major source for AMR because focus to enhance its production by modern practices widely uses antibiotics. India and China are major producers of meat and have hotspots of AMR. The Central and Southern India were predicted as emerging hotspots for AMR in poultry but no data available to substantiate it. To this end, we collected chicken feces from poultry farms in these regions and isolated genomic DNA. Further, shotgun whole genome sequencing was performed for metagenomics analysis. For the first time, we report the AMR gene profiles in poultry from Kerala and Telangana. The samples exhibited a higher prevalence of gram-negative and anaerobic species. The high priority pathogens in India were detected, like E.coli, Clostridium perfringens, Klebsiella pneumonia Staphylococcus aureus, Enterococcous faecalis, Pseudomonas aeruginosa, Bacteriodes fragiles. Conspicuously, the Southern India had the highest abundance of AMR genes than the Central India. E.coli was significantly more prevalent in the southernmost zone of India than in other sites. Our data had many common AMR profile features of the European Union (EU) poultry farms but lacked mcr-1, which was a lately emerged AMR gene in E.coli. Our data revealed the extent of AMR gene evolved in the Central and Southern India. It is comparable to the EU data but severity is lesser than in the EU.

The bacterial serine protease inhibitor ecotin inhibits neutrophil elastase enzymatic activity in cystic fibrosis sputa

Cystic Fibrosis (CF) airway disease is characterized by impaired mucociliary clearance, chronic, polymicrobial infections and robust, neutrophil-dominated inflammation. Pulmonary disease is the leading cause of morbidity and mortality in people with CF and is due to progressive airflow obstruction and ultimately respiratory failure. One of the earliest abnormalities in CF airway disease is the recruitment of neutrophils to the lungs. Neutrophil activation leads to the release of their intracellular content, including neutrophil elastase (NE), that damages lung tissues in CF. Our goal is to characterize a known bacterial NE inhibitor, ecotin, in the CF airway environment. Our results indicate that ecotins cloned from four Gram-negative bacterial species (Campylobacter rectus, Campylobacter showae, Escherichia coli and Pseudomonas aeruginosa) inhibit NE activity in CF sputum samples in a dose-dependent manner. Although we observed differences in the NE-inhibitory activity of the tested ecotins with the Campylobacter homologs being the most effective in NE inhibition in CF sputa, none of the ecotins impaired the ability of human neutrophils to kill major CF respiratory pathogens, P. aeruginosa or S. aureus, in vitro. Overall, we demonstrate that bacterial ecotins inhibit NE activity in CF sputa without compromising bacterial killing by neutrophils.

Molecular characterization of blaTEM and blaCTX-M ESBLs genes producing Escherichia coli isolates from urinary tract infections (UTIs) in Al-Basrah province, Iraq

Urinary tract infections (UTIs) are primarily caused by Gram-negative Enterobacteriaceae bacteria, accounting for 80–90% of uropathogenic Escherichia coli infections. Multidrug-resistant (MDR) bacteria, such as extended-spectrum β-lactamases (ESBLS), pose a significant threat to global healthcare systems. The current study relied on 200 urine samples collected from patients suffering urinary tract infections (UTIs) in Al Sadr Teaching Hospital in Al-Basrah Province,Iraq from the 5th January to 22nd February. A result of cultivated 200 samples collected from urinary tract infection patients showed 71 (35.5%) positive samples on MacConkey agar, eosin methylene blue (EMB), and HiChromeTM E.coli agar, and bacterial growth was distributed to 47 (66.2%) Escherichia coli and 24 (33.8%) of Gram-negative species. The diagnostic gene 16S rDNA by PCR method showed that all 47 E. coli isolates had a molecular weight of around 585 bp at 100%. Furthermore, positive results were shown in 44 (93.6%) of the E.coli isolates in the current study that produced ESBLs by using the double-disc approximation method (DAM). While 3 (6.4%) isolates revealed negative results for ESBLs, whereas the13(27.7%) of the E.coli isolates gave positive results for ESBL. While 34(72.3%) E.coli isolates showed negative results for produced ESBLs by using the double-disc synergy test (DDST), there were significant differences (P<0.01) between positive and negative isolates in both methods used to detect ESBL-producing isolates. Extended-spectrum β-lactamses (ESBLs) genes were detected by using PCR to amplify the blaTEM and blaCTX-M genes in E.coli isolates. The amplified genes' bands were characterised approximately at (800 bp) for blaTEM and (754 bp) for blaCTX-M , the products were compared to the standard molecular DNA ladder at (2000 bp). According to the results, 47(100%) E.coli isolates gave positive results for the blaTEM gene. While blaCTX-M gene was shown, only 23(48.9%) E.coli isolates had positive results for the blaCTX-M gene.

Computer-aided drug design to generate a unique antibiotic family.

The World Health Organization has identified antibiotic resistance as one of the three greatest threats to human health. The need for antibiotics is a pressing matter that requires immediate attention. Here, computer-aided drug design is used to develop a structurally unique antibiotic family targeting holo-acyl carrier protein synthase (AcpS). AcpS is a highly conserved enzyme essential for bacterial survival that catalyzes the first step in lipid synthesis. To the best of our knowledge, there are no current antibiotics targeting AcpS making this drug development program of high interest. We synthesize a library of > 700 novel compounds targeting AcpS, from which 33 inhibit bacterial growth in vitro at ≤ 2 μg/mL. We demonstrate that compounds from this class have stand-alone activity against a broad spectrum of Gram-positive organisms and synergize with colistin to enable coverage of Gram-negative species. We demonstrate efficacy against clinically relevant multi-drug resistant strains in vitro and in animal models of infection in vivo including a difficult-to-treat ischemic infection exemplified by diabetic foot ulcer infections in humans. This antibiotic family could form the basis for several multi-drug-resistant antimicrobial programs.

Antibacterial synergistic effect of sea cucumber extract and kelulut honey combination

Natural products remain one of the major sources of new drug molecules today. The combination of sea cucumber extract with stingless bee honey holds great potential for health supplement. However, the specific results of the combination have yet to be determined. In this study, the antibacterial activity of kelulut honey and Phyllophorus spiculata sea cucumber extract samples individually and in combination were assessed with disk-diffusion assays and broth dilution method. Most of the samples exhibit small or absence of inhibitory activity using disk-diffusion assay method. Only kelulut honey sample with 100% concentration has a positive antagonism effect against Escherichia coli and Staphylococcus epidermidis. For the broth dilution method, Gram-positive bacteria were found to be more susceptible as compared to Gram-negative bacteria species, with lower minimum inhibitory concentration (MIC) value of kelulut honey, sea cucumber or combination sample. The growth of gram-positive S. epidermidis is inhibited by sea cucumber extract at MIC value of 0.031 mg/mL, kelulut honey at MIC value of 0.063 mg/ mL and combination sample at MIC value of 0.063 mg/mL, all of which are of lower MIC value as compared to E. coli inhibition. The absorbance at optical density (OD) 600nm wavelength was also measured to monitor the growth of bacteria in solution. From the results, broth dilution proves to be a more effective method to assess the antibacterial activity in the combination samples. Two combinations showed the best antibacterial synergy (OD600 value of 0.000) against both Gram-positive and Gram-negative bacteria, which were (1) ½ sea cucumber: ½ kelulut honey combination and (2) ¾ sea cucumber: ¼ kelulut honey combination. This preliminary evidence on their antibacterial synergistic activities is promising and shows possible commercialization potential.

Detection and Measurement of Bacterial Contaminants in Stored River Water Consumed in Ekpoma

This study was conducted in Ekpoma, a town dependent on rainwater and river water from nearby areas because of a lack of groundwater sources, and the physicochemical and bacteriological (heterotrophic plate count [HPC], total coliform count [TCC], and fecal coliform count [FCC]) properties of 123 stored river water samples grouped into five collection districts (EK1 to EK5). The results were compared with regulatory standards and previous regional studies to identify water quality trends. While most physicochemical properties met drinking water standards, 74% of samples had pH values > 8.5. Twenty-seven samples were fit for drinking, with EK4 having the highest number of bacterio-logically unsuitable samples. Ten bacterial species were identified, with Gram-negative short-rod species such as Escherichia coli, Klebsiella pneumoniae, and Salmonella typhimurium being predominant. HPC values varied from 367 × 10⁴ to 1320 × 10⁴ CFU/mL, with EK2 (2505 × 10⁴ CFU/mL) and EK5 (1320 × 10⁴ CFU/mL) showing particularly high counts. The TCC values ranged from 1049 × 10⁴ to 4400 × 10⁴ CFU/mL, and the FCC values from 130 × 10⁴ to 800 × 10⁴ CFU/mL, all exceeding WHO limits (1.0 × 102 CFU/mL). Historical data show no improvement in water quality, emphasizing the need for individuals to treat water properly before consumption. The findings provide baseline data for local water authorities and serve as a wake-up call for adequate water treatment, storage interventions, and community education on water security. Additionally, this study offers a practical process for improving the quality of water stored in similar regions.

Novel Drug-like HsrA Inhibitors Exhibit Potent Narrow-Spectrum Antimicrobial Activities against Helicobacter pylori.

Helicobacter pylori infection constitutes a silent pandemic of global concern. In the last decades, the alarming increase in multidrug resistance evolved by this pathogen has led to a marked drop in the eradication rates of traditional therapies worldwide. By using a high-throughput screening strategy, in combination with in vitro DNA binding assays and antibacterial activity testing, we identified a battery of novel drug-like HsrA inhibitors with MIC values ranging from 0.031 to 4 mg/L against several antibiotic-resistant strains of H. pylori, and minor effects against both Gram-negative and Gram-positive species of human microbiota. The most potent anti-H. pylori candidate demonstrated a high therapeutic index, an additive effect in combination with metronidazole and clarithromycin as well as a strong antimicrobial action against Campylobacter jejuni, another clinically relevant pathogen of phylum Campylobacterota. Transcriptomic analysis suggests that the in vivo inhibition of HsrA triggers lethal global disturbances in H. pylori physiology including the arrest of protein biosynthesis, malfunction of respiratory chain, detriment in ATP generation, and oxidative stress. The novel drug-like HsrA inhibitors described here constitute valuable candidates to a new family of narrow-spectrum antibiotics that allow overcoming the current resistome, protecting from dysbiosis, and increasing therapeutic options for novel personalized treatments against H. pylori.

Multidrug-Resistant Proteus mirabilis and Other Gram-Negative Species Isolated from Native Egyptian Chicken Carcasses.

Poultry carcasses may be reservoirs for the zoonotic transmission of antimicrobial-resistant bacteria to humans and pose a major public health hazard. During the isolation of Salmonella from poultry and other foods, many of the presumptive typical Salmonella colonies on xylose lysine deoxycholate (XLD) agar were found to lack the invA gene, which is the specific target gene for Salmonella spp. Therefore, the current study aimed to estimate the prevalence and antimicrobial resistance profiles of extensively drug-resistant invA-negative non-Salmonella isolates recovered from native Egyptian chicken carcasses as presumptive Salmonella colonies on XLD agar. The non-Salmonella isolates were detected in 84% (126/150) of the examined native Egyptian chicken carcasses and classified into five genera, with prevalence rates of 64% (96/150), 14% (21/150), 6.7% (10/150), 3.3% (5/150), and 1.3% (2/150) for Proteus, Citrobacter, Shigella, Pseudomonas, and Edwardsiella, respectively. One hundred and ninety-five invA-negative, non-verified presumptive Salmonella isolates were recovered and classified at the species level into Proteus mirabilis (132/195; 67.7%), Proteus vulgaris (11/195; 5.6%), Citrobacter freundii (26/195; 13.3%), Shigella flexneri (8/195; 4.1%), Shigella sonnei (6/195; 3.1%), Shigella dysenteriae (3/195; 1.5%), Pseudomonas fluorescens (6/195; 3.1%), and Edwardsiella tarda (3/195; 1.5%). All (195/195; 100%) of these isolates showed resistance against cefaclor and fosfomycin. Additionally, these isolates showed high resistance rates of 98%, 92.8%, 89.7%, 89.2%, 89.2%, 86.7%, 80%, 78.5%, 74.4%, and 73.9% against cephalothin, azithromycin, vancomycin, nalidixic acid, tetracycline, sulfamethoxazole/trimethoprim, cefepime, gentamicin, cefotaxime, and ciprofloxacin, respectively. Interestingly, all (195/195; 100%) of the identified isolates were resistant to at least five antibiotics and exhibited an average MAR (multiple antibiotic resistance) index of 0.783. Furthermore, 73.9% of the examined isolates were classified as extensively drug-resistant, with an MAR index equal to 0.830. The high prevalence of extensively drug-resistant foodborne Proteus, Citrobacter, Shigella, Pseudomonas, and Edwardsiella isolated from native chicken carcasses poses a great hazard to public health and necessitates more monitoring and concern about the overuse and misuse of antibiotics in humans and animals. This study also recommends the strict implementation of GHP (good hygienic practices) and GMP (good manufacturing practices) in the chicken meat supply chain to protect consumer health.

Trends of Antimicrobial Sensitivity Among Common Isolates in a Tertiary Care Hospital, Rawalpindi

Objective: To evaluate the resistance patterns of frequently found pathogens to different antimicrobial agents, aiding physicians in choosing appropriate treatment strategies for patients within our locality. Materials and Method: This retrospective observational study took place at Pakistan Railway hospital (PRH) Rawalpindi; from January 2021 to December 2021. Data was obtained from the institute's database, the Hospital Information Management System (HIMS). Pathogens were identified in the laboratory through Gram staining and biochemical tests, and their antibiotic sensitivity profiles using disk diffusion method assessed following protocols established by the Clinical & Laboratory Standards Institute. Statistical analysis was conducted using SPSS version 24, and data entry was carried out accordingly. Results: Overall, 1128 positive cultures were reported in study period including urine, pus, HVS, sputum cultures, stool, blood, catheter tip, and others (tissue fluid, wound, and cannula tip etc.). They comprised 32.8 %, 30.9 %, 16.6%, 5.05 %, 3.81%, 3.72 %, 1.15%, 0.70 % and 0.08% of the other specimens respectively. Among the isolates, Escherichia coli revealed 31.4% resistance against one of the third-generation cephalosporin and 8% to imipenem while Klebsiella pneumoniae exhibited 58.7% resistance. Moreover 82% Staphylococcus aureus were resistant to oxacillin, and 6% to vancomycin. Conclusion: Moderate to reduced susceptibility to frequently utilized antimicrobials has been noted across diverse gram-positive and gram-negative species, apart from Penicillin. To address the escalating resistance to carbapenems and cephalosporins, it is essential to establish and enforce rigorous infection control measures.