Dual Drug-Loaded Coaxial Nanofiber Dressings for the Treatment of Diabetic Foot Ulcer.

Introduction: Diabetes mellitus is frequently associated with foot ulcers, which pose significant health risks and complications. Impaired wound healing in diabetic patients is attributed to multiple factors, including hyperglycemia, neuropathy, chronic inflammation, oxidative damage, and decreased vascularization. Rationale: To address these challenges, this project aims to develop bioactive, fast-dissolving nanofiber dressings composed of polyvinylpyrrolidone loaded with a combination of an antibiotic (moxifloxacin or fusidic acid) and anti-inflammatory drug (pirfenidone) using electrospinning technique to prevent the bacterial growth, reduce inflammation, and expedite wound healing in diabetic wounds. Results: The fabricated drug-loaded fibers exhibited diameters of 443 ± 67 nm for moxifloxacin/pirfenidone nanofibers and 488 ± 92 nm for fusidic acid/pirfenidone nanofibers. The encapsulation efficiency, drug loading and drug release studies for the moxifloxacin/pirfenidone nanofibers were found to be 70 ± 3% and 20 ± 1 µg/mg, respectively, for moxifloxacin, and 96 ± 6% and 28 ± 2 µg/mg, respectively, for pirfenidone, with a complete release of both drugs within 24 hours, whereas the fusidic acid/pirfenidone nanofibers were found to be 95 ± 6% and 28 ± 2 µg/mg, respectively, for fusidic acid and 102 ± 5% and 30 ± 2 µg/mg, respectively, for pirfenidone, with a release rate of 66% for fusidic acid and 80%, for pirfenidone after 24 hours. The efficacy of the prepared nanofiber formulations in accelerating wound healing was evaluated using an induced diabetic rat model. All tested formulations showed an earlier complete closure of the wound compared to the controls, which was also supported by the histopathological assessment. Notably, the combination of fusidic acid and pirfenidone nanofibers demonstrated wound healing acceleration on day 8, earlier than all tested groups. Conclusion: These findings highlight the potential of the drug-loaded nanofibrous system as a promising medicated wound dressing for diabetic foot applications.

Evaluation of Xpert MTB/RIF Ultra for the Diagnosis of Extrapulmonary Tuberculosis: A Retrospective Analysis in Saudi Arabia.

The incidence of extrapulmonary tuberculosis (EPTB) in low- and middle-income countries, as well as, high-income countries has increased over the last two decades. The acid-fast bacillus (AFB) smear test is easy to perform and cost-effective with a quick turnaround time but the test has low sensitivity. Culture remains the gold standard for detecting TB; however, it has low sensitivity and slow bacterial growth patterns, as it may take up to 6 to 8 weeks to grow. Therefore, a rapid detection tool is crucial for the early initiation of treatment and ensuring an improved therapeutic outcome. Here, the Xpert Ultra system was developed as a nucleic acid amplification technique to accelerate the detection of MTB in paucibacillary clinical samples and endorsed by the World Health Organization. From March 2020 to August 2021, Xpert Ultra was evaluated for its sensitivity and specificity against EPTB and compared with those of the routinely used Xpert, culture, and AFB tests in 845 clinical samples in Saudi Arabia. The results indicate the overall sensitivity and specificity of Xpert Ultra to be 91% and 95%, respectively, compared with the Xpert (82% and 99%, respectively) and AFB smear (18% and 100%, respectively) tests. The results also indicated that despite the low microbial loads that were categorized as trace, very low, or low on Xpert Ultra, yet, complete detection was achieved with some sample types (i.e., 100% detection). Consequently, Xpert Ultra has great potential to replace conventional diagnostic approaches as a standard detection method for EPTB.

Identification and Characterization of Plasmids and Genes from Carbapenemase-Producing Klebsiella pneumoniae in Makkah Province, Saudi Arabia.

Klebsiella pneumoniae (K. pneumoniae) is involved in several hospital and community-acquired infections. The prevalence of K. pneumoniae-producing-carbapenemase (KPC) resistance genes rapidly increases and threatens public health worldwide. This study aimed to assess the antibiotic resistance level of K. pneumoniae isolates from Makkah Province, Saudi Arabia, during the Islamic 'Umrah' ritual and to identify the plasmid types, presence of genes associated with carbapenem hydrolyzing enzymes, and virulence factors. The phenotypic and genotypic analyses based on the minimum inhibitory concentration (MIC), biofilm formation, PCR, and characterization of KPC-encoding plasmids based on the replicon typing technique (PBRT) were explored. The results showed that most isolates were resistant to carbapenem antibiotics and other antibiotics classes. This study identified sixteen different replicons of plasmids in the isolates and multiple genes encoding carbapenem factors, with blaVIM and blaOXA-48 being the most prevalent genes identified in the isolates. However, none of the isolates exhibited positivity for the KPC production activity. In addition, this study also identified six virulence-related genes, including kfu, wabG, uge, rmpA, fimH, and a capsular polysaccharide (CPS). Together, the data reported in this study indicate that the isolated K. pneumoniae during the pilgrimage in Makkah were all resistant to carbapenem antibiotics. Although the isolates lacked KPC production activity, they carried multiple carbapenem-resistant genes and virulence factors, which could drive their resistant phenotype. The need for specialized methods for KPC detection, monitoring the possibility of nosocomial transmission, and diverse therapeutic alternatives are necessary for controlling the spreading of KPC. This study can serve as a reference for clinicians and researchers on types of K. pneumoniae commonly found during religious gathering seasons in Saudi Arabia.

Development and Validation of Reverse Transcriptase Loop-Mediated Isothermal Amplification (RT-LAMP) as a Simple and Rapid Diagnostic Tool for SARS-CoV-2 Detection.

Since the COVID-19 pandemic outbreak in the world, many countries have searched for quick diagnostic tools to detect the virus. There are many ways to design diagnostic assays; however, each may have its limitations. A quick, sensitive, specific, and simple approach is essential for highly rapidly transmitted infections, such as SARS-CoV-2. This study aimed to develop a rapid and cost-effective diagnostic tool using a one-step Reverse Transcriptase Loop-Mediated Isothermal Amplification (RT-LAMP) approach. The results were observed using the naked eye within 30-60 min using turbidity or colorimetric analysis. The sensitivity, specificity, and lowest limit of detection (LoD) for SARS-CoV-2 RNA against the RT-LAMP assay were assessed. This assay was also verified and validated against commercial quantitative RT-PCR used by health authorities in Saudi Arabia. Furthermore, a quick and direct sampling from the saliva, or buccal cavity, was applied after simple modification, using proteinase K and heating at 98 °C for 5 min to avoid routine RNA extraction. This rapid single-tube diagnostic tool detected COVID-19 with an accuracy rate of 95% for both genes (ORF1a and N) and an LoD for the ORF1a and N genes as 39 and 25 copies/reaction, respectively. It can be potentially used as a high-throughput national screening for different respiratory-based infections within the Middle East region, such as the MERS virus or major zoonotic pathogens such as Mycobacterium paratuberculosis and Brucella spp., particularly in remote and rural areas where lab equipment is limited.

Liposome-Encapsulated Tobramycin and IDR-1018 Peptide Mediated Biofilm Disruption and Enhanced Antimicrobial Activity against Pseudomonas aeruginosa.

The inadequate eradication of pulmonary infections and chronic inflammation are significant complications in cystic fibrosis (CF) patients, who usually suffer from persistent and frequent lung infections caused by several pathogens, particularly Pseudomonas aeruginosa (P. aeruginosa). The ability of pathogenic microbes to protect themselves from biofilms leads to the development of an innate immune response and antibiotic resistance. In the present work, a reference bacterial strain of P. aeruginosa (PA01) and a multidrug-resistant isolate (MDR 7067) were used to explore the microbial susceptibility to three antibiotics (ceftazidime, imipenem, and tobramycin) and an anti-biofilm peptide (IDR-1018 peptide) using the minimum inhibition concentration (MIC). The most effective antibiotic was then encapsulated into liposomal nanoparticles and the IDR-1018 peptide with antibacterial activity, and the ability to disrupt the produced biofilm against PA01 and MDR 7067 was assessed. The MIC evaluation of the tobramycin antibacterial activity showed an insignificant effect on the liposomes loaded with tobramycin and liposomes encapsulating tobramycin and IDR-1018 against both P. aeruginosa strains to free tobramycin. Nevertheless, the biofilm formation was significantly reduced (p < 0.05) at concentrations of ≥4 µg/mL and ≤32 µg/mL for PA01 and ≤32 µg/mL for MDR 7067 when loading tobramycin into liposomes, with or without the anti-biofilm peptide compared to the free antibiotic, empty liposomes, and IDR-1018-loaded liposomes. A tobramycin concentration of ≤256 µg/mL was safe when exposed to a lung carcinoma cell line upon its encapsulation into the liposomal formulation. Tobramycin-loaded liposomes could be a potential candidate for treating lung-infected animal models owing to the high therapeutic efficacy and safety profile of this system compared to the free administration of the antibiotic.

Melittin from Bee Venom Encapsulating Electrospun Fibers as a Potential Antimicrobial Wound Dressing Patches for Skin Infections.

Skin infection compromises the body's natural defenses. Several antibiotics are no longer effective owing to the evolution of antimicrobial-resistant (AMR) bacteria, hence, the constant development of novel antibacterial agents. Naturally occurring antibacterial agents may be potential candidates for AMR bacterial infection treatments; however, caution should be taken when administering such agents due to the high incidence of toxicity. A fibrous material system from a biocompatible polymer that could be used as a skin patch for skin infections treatment caused by AMR bacteria is proposed in this study. Bee venom's active ingredient, melittin, was fabricated using electrospinning technology. Scanning electron microscopy showed that melittin-loaded fibers had smooth surfaces with no signs of beads or pores. The average diameter of this fibrous system was measured to be 1030 ± 160 nm, indicating its successful preparation. The melittin fibers' drug loading and entrapment efficiency (EE%) were 49 ± 3 µg/mg and 84 ± 5%, respectively. This high EE% can be another successful preparatory criterion. An in vitro release study demonstrated that 40% of melittin was released after 5 min and achieved complete release after 120 min owing to the hydrophilic nature of the PVP polymer. A concentration of ≤10 µg/mL was shown to be safe for use on human dermal fibroblasts HFF-1 after 24-h exposure, while an antibacterial MIC study found that 5 µg/mL was the effective antimicrobial concentration for S. aureus, A. baumannii, E. coli and Candida albicans yeast. A melittin-loaded fibrous system demonstrated an antibacterial zone of inhibition equivalent to the control (melittin discs), suggesting its potential use as a wound dressing patch for skin infections.

Assessment of the Antibacterial Efficacy of Halicin against Pathogenic Bacteria.

Artificial intelligence (AI) is a new technology that has been employed to screen and discover new drugs. Using AI, an anti-diabetic treatment (Halicin) was nominated and proven to have a unique antibacterial activity against several harmful bacterial strains, including multidrug-resistant bacteria. This study aims to explore the antibacterial effect of halicin and microbial susceptibility using the zone of inhibition and the minimum inhibition concentration (MIC) values while assessing the stability of stored halicin over a period of time with cost-effective and straightforward methods. Linear regression graphs were constructed, and the correlation coefficient was calculated. The new antibacterial agent was able to inhibit all tested gram-positive and gram-negative bacterial strains, but in different concentrations-including the A. baumannii multidrug-resistant (MDR) isolate. The MIC of halicin was found to be 16 µg/mL for S. aureus (ATCC BAA-977), 32 µg/mL for E. coli (ATCC 25922), 128 µg/mL for A. baumannii (ATCC BAA-747), and 256 µg/mL for MDR A. baumannii. Upon storage, the MICs were increased, suggesting instability of the drug after approximately a week of storage at 4 °C. MICs and zones of inhibition were found to be high (R = 0.90 to 0.98), suggesting that halicin has a promising antimicrobial activity and may be used as a wide-spectrum antibacterial drug. However, the drug's pharmacokinetics have not been investigated, and further elucidation is needed.

Preparation and evaluation of benzalkonium chloride hand sanitizer as a potential alternative for alcohol-based hand gels.

Hand hygiene is one of the effective measures for reducing the transmission of infections. Alcohol-based hand sanitizers containing ethanol or isopropanol are considered efficient alternatives to handwashing with water and soap. Despite being effective against a broad-spectrum of microbes, fining an effective alternative to the alcohol-based hand sanitizers became a necessity owning to the limitations associated with their use, such as skin dryness, irritant contact dermatitis, and intoxication upon their accidental ingestion. Furthermore, in certain circumstances when the demand for alcohol exceeds the supply, like in the current COVID19 pandemic, formulating an effective non-alcoholic hand sanitizer would be a potential solution. Therefore, in this study, a non-alcoholic hand sanitizer containing benzalkonium chloride (BKC) as an active ingredient was prepared and evaluated as a less irritant and more persistent hand sanitizer gel. The hand gel was characterized by pH, viscosity, and spreadability. Results showed that this product has low viscosity, high spreadability and pH of 6.3, which is less likely to cause skin irritation. The antibacterial assessment (zone of inhibition) of the BKC-based hand sanitizer demonstrated antibacterial activities against nine out of eleven gram-positive and gram-negative bacterial strains, while the acceptability study on ten participants showed no signs of skin irritation nor redness upon its application. Consequently, this non-alcoholic based hand sanitizer is suggested as a potential alternative to alcohol-based hand gels.

Formulation and Evaluation of Alcohol-Free Hand Sanitizer Gels to Prevent the Spread of Infections during Pandemics.

Hand hygiene is an essential factor to prevent or minimize the spread of infections. The ability to prepare an alcohol-free hand sanitizer (AFHS) with antimicrobial properties is crucial, especially during pandemics, when there are high demands and a low supply chain for ethanol and isopropanol. The objective of this study was to prepare AFHS gels based on natural materials that contain essential oils (EOs) that would be effective against a broad spectrum of pathogens. The results showed that the organoleptic characteristics of all prepared hand sanitizer gels were considered acceptable. The pH of the formulations was slightly acidic (circa 3.9) owing to the presence of aloe vera in large proportions (90% v/v), which is known for its acidity. The spreadability for all tested formulations was in the acceptable range. The antimicrobial effectiveness test demonstrated that the prepared hand sanitizer gels had antimicrobial activities against different gram-positive and gram-negative bacteria and Candida albicans yeast. The highest antibacterial effect was observed with tea tree oil hand sanitizers, which lack activity against the yeast, while clove oil hand sanitizers showed effectiveness against all microorganisms, including Candida albicans. The lavender hand sanitizer exhibited the least antimicrobial efficiency. The acceptability study on 20 human volunteers showed that the hand sanitizer gel containing 1.25% (v/v) clove oil did not produce any signs of skin irritation. This study suggested that the prepared natural hand sanitizer gel with 1.25% (v/v) clove oil can be a potential alternative to commonly used alcohol-based hand sanitizers (ABHS).

Short-term improvement of clinical parameters and microbial diversity in periodontitis patients following Indocyanine green-based antimicrobial photodynamic therapy: A randomized single-blind split-mouth cohort.

BACKGROUND: Indocyanine green-mediated photodynamic therapy is effective against chronic periodontitis. Here, we evaluated the efficiency of indocyanine green-based adjunctive antimicrobial photodynamic therapy in non-surgical treatment of chronic periodontitis patients. METHODS: Fifty-six periodontally involved teeth of 20 patients were treated with "scaling and root planing" (control group) or "scaling and root planing with indocyanine green-based (perio-green, 0.1 mg/ml) antimicrobial photodynamic therapy" (test group) using a split-mouth design. We performed clinical assessment of probing depth, gingival recession, clinical attachment loss, and other indices, while plaque samples were collected for microbiome analysis. RESULTS: At baseline, periodontal depth and clinical attachment loss were significantly higher in the test group (p < 0.05), and at 1-month post-treatment, we observed a significant favorable reduction of both periodontal depth and clinical attachment loss in test and control sites, with lower means maintained at 3 months (p = 0.01 and p = 0.000, respectively). Additionally, analysis of variance showed significant improvements in periodontal depth and clinical attachment loss in the indocyanine green-antimicrobial photodynamic therapy group (p = 0.001), although not for clinical attachment loss in controls (p = 0.102). Moreover, a significant reduction was observed in test sites for bleeding on probing and residual pocket post-therapy (p = 0.04 and p = 0.0001 respectively). Furthermore, microbiome analysis identified Porphyromonons gingivalis, Treponema, and Tannerella in all samples with favorable changes in test sites (p = 0.07). CONCLUSION: We observed a significant reduction in periodontal clinical parameters (periodontal depth and clinical attachment loss) in chronic periodontitis patients treated with antimicrobial photodynamic therapy as an adjunctive procedure to conventional scaling and root planing. This improvement was associated with periodontal pathogen reduction and increase in the healthy subgingival microbiome.

The Delivery of the Novel Drug 'Halicin' Using Electrospun Fibers for the Treatment of Pressure Ulcer against Pathogenic Bacteria.

Pressure ulcer or bedsore is a form of skin infection that commonly occurs with patients admitted to the hospital for an extended period of time, which might lead to severe complications in the absence of medical attention, resulting in infection either by drug-sensitive or drug-resistant bacteria. Halicin, a newly discovered drug effective against several bacterial strains, including multidrug-resistant bacteria, was investigated to reduce bacterial infection burden. This study aims to formulate halicin into electrospun fibers to be applied in bedsores as antibacterial dressing to assess its efficacy against gram-positive (Staphylococcus aureus) and gram-negative bacteria (Escherichia coli and Acinetobacter baumannii) by studying the minimum inhibitory concentration (MIC) and bacterial zone of inhibition assays. The diameters of inhibition growth zones were measured, and the results have shown that the drug-loaded fibers were able to inhibit the growth of bacteria compared to the halicin discs. The release profile of the drug-loaded fibers exhibited a complete release of the drug after 2 h. The results demonstrated that the drug-loaded fibers could successfully release the drug while retaining their biological activity and they may be used as a potential antimicrobial dressing for patients with pressure ulcers caused by multidrug resistant bacteria.

Microbial dysbiosis in irritable bowel syndrome: A single-center metagenomic study in Saudi Arabia.

BACKGROUND: The focus of this study was to explore potential differences in colonic mucosal microbiota in irritable bowel syndrome (IBS) patients compared to a control group utilizing a metagenomic study. METHODS: Mucosal microbiota samples were collected from each IBS patient utilizing jet-flushing colonic mucosa in unified segments of the colon with distilled water, followed by aspiration, during colonoscopy. All the purified dsDNA was extracted and quantified before metagenomic sequencing using an Illumina platform. An equal number of healthy age-matched controls were also examined for colonic mucosal microbiota, which were obtained during screening colonoscopies. RESULTS: The microbiota data on 50 IBS patients (31 females), with a mean age 43.94 ± 14.50 (range19-65), were analyzed in comparison to 50 controls. Satisfactory DNA samples were subjected to metagenomics study, followed by comprehensive comparative phylogenetic analysis. Metagenomics analysis was carried out, and 3.58G reads were sequenced. Community richness (Chao) and microbial structure in IBS patients were shown to be significantly different from those in the control group. Enrichment of Oxalobacter formigenes, Sutterella wadsworthensis, and Bacteroides pectinophilus was significantly observed in controls, whereas enrichment of Collinsella aerofaciens, Gemella morbillorum, and Veillonella parvula Actinobacteria was observed significantly in the IBS cohort. CONCLUSION: The current study has demonstrated significant differences in the microbiota of IBS patients compared to controls.

Publisher Correction: Genomic analysis of the emergence of drug-resistant strains of Mycobacterium tuberculosis in the Middle East.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Microbial dysbiosis in inflammatory bowel diseases: results of a metagenomic study in Saudi Arabia.

BACKGROUND: The intestinal microbiota plays an essential role in the pathogenesis of ulcerative colitis (UC)and Crohn disease (CD). METHODS: Metagenomic studies were used to study microbiota in the diagnosed cases of UC and CD at King Fahad Medical City, Riyadh, Saudi Arabia. Each segment of the colon was flushed with distilled water during colonoscopy, and the material was aspirated, immediately frozen for the study. The patients attending for screening colonoscopies were taken as age-matched healthy controls. The UC patients were followed clinically for any signs of exacerbation relapse, and CD patients were followed for any complications. RESULTS: The metagenomic data on 46 (24 females) patients with CD were analyzed along with a group of age and gender-matched controls. Their age ranged from 14 to 65 years, mean age 25.19±10.67 years. There were 50 UC patient (28 females) mean age of 34.42±12.58, and their age ranged from 13-58 years. This study identified enrichment of 19 genera in the control group (Abiotrophia, Anaerofustis, Butyrivibrio, Campylobacter, Catenibacterium, Coprococcus, Dorea, Eubacterium, Facklamia, Klebsiella, Lactococcus, Oscillibacter, Paenibacillus, Parabacteroides, Parasutterella, Porphyromonas, Prevotella, Ruminococcus, Treponema). There was a significant enrichment of 14 genera in our CD cohort (Beggiatoa, Burkholderia, Cyanothece, Enterococcus, Escherichia, Fusobacterium, Jonquetella, Mitsuokella, Parvimonas, Peptostreptococcus, Shigella, Succinatimonas, ThermoanaerobacterVerrucomicrobiales, Vibrio). There was a significant enrichment of 7 genera in UC cohort (Beggiatoa, Burkholderia, Parascardovia, Parvimonas, Pseudoflavonifractor, Thermoanaerobacter, Verrucomicrobiales). CONCLUSIONS: A significant dysbiosis was found in UC and CD patients compared to controls.

Old World cutaneous leishmaniasis treatment response varies depending on parasite species, geographical location and development of secondary infection.

BACKGROUND: In the Kingdom of Saudi Arabia (KSA), Leishmania major and L. tropica are the main causative agents of Old World cutaneous leishmaniasis (CL). The national CL treatment regimen consists of topical 1% clotrimazole/2% fusidic acid cream followed by 1-2 courses of intralesional sodium stibogluconate (SSG); however, treatment efficacy is highly variable and the reasons for this are not well understood. In this study, we present a complete epidemiological map of CL and determined the efficacy of the standard CL treatment regime in several endemic regions of KSA. RESULTS: Overall, three quarters of patients in all CL-endemic areas studied responded satisfactorily to the current treatment regime, with the remaining requiring only an extra course of SSG. The majority of unresponsive cases were infected with L. tropica. Furthermore, the development of secondary infections (SI) around or within the CL lesion significantly favoured the treatment response of L. major patients but had no effect on L. tropica cases. CONCLUSIONS: The response of CL patients to a national treatment protocol appears to depend on several factors, including Leishmania parasite species, geographical location and occurrences of SI. Our findings suggest there is a need to implement alternative CL treatment protocols based on these parameters.

Genomic analysis of the emergence of drug-resistant strains of Mycobacterium tuberculosis in the Middle East.

Tuberculosis (TB) represents a significant challenge to public health authorities, especially with the emergence of drug-resistant (DR) and multidrug-resistant (MDR) isolates of Mycobacterium tuberculosis. We sought to examine the genomic variations among recently isolated strains of M. tuberculosis in two closely related countries with different population demography in the Middle East. Clinical isolates of M. tuberculosis from both Egypt and Saudi Arabia were subjected to phenotypic and genotypic analysis on gene and genome-wide levels. Isolates with MDR phenotypes were highly prevalent in Egypt (up to 35%) despite its relatively stable population structure (sympatric pattern). MDR-TB isolates were not identified in the isolates from Saudi Arabia despite its active guest worker program (allopatric pattern). However, tuberculosis isolates from Saudi Arabia, where lineage 4 was more prevalent (>65%), showed more diversity than isolates from Egypt, where lineage 3 was the most prevalent (>75%). Phylogenetic and molecular dating analyses indicated that lineages from Egypt were recently diverged (~78 years), whereas those from Saudi Arabia were diverged by over 200 years. Interestingly, DR isolates did not appear to cluster together or spread more widely than drug-sensitive isolates, suggesting poor treatment as the main cause for emergence of drug resistance rather than more virulence or more capacity to persist.

Colonic Mucosal Microbiota in Colorectal Cancer: A Single-Center Metagenomic Study in Saudi Arabia.

BACKGROUND AND AIM: Because genetic and geographic variations in intestinal microbiota are known to exist, the focus of this study was to establish an estimation of microbiota in colorectal cancer (CRC) patients in Saudi Arabia by means of metagenomic studies. METHODS: From July 2010 to November 2012, colorectal cancer patients attending our hospital were enrolled for the metagenomic studies. All underwent clinical, endoscopic, and histological assessment. Mucosal microbiota samples were collected from each patient by jet-flushing colonic mucosa with distilled water at unified segments of the colon, followed by aspiration, during colonoscopy. Total purified dsDNA was extracted and quantified prior to metagenomic sequencing using an Illumina platform. Satisfactory DNA samples (n = 29) were subjected to metagenomics studies, followed by comprehensive comparative phylogenetic analysis. An equal number of healthy age-matched controls were also examined for colonic mucosal microbiota. RESULTS: Metagenomics data on 29 patients (14 females) in the age range 38-77 years were analyzed. The majority 11 (37%) of our patients were overweight (BMI = 25-30). Rectal bleeding was the presenting symptom in 18/29 (62%), while symptomatic anemia was the presenting symptom in 11/29 (37%). The location of colon cancer was rectal in 14 (48%), while cecal growth was observed in 8 (27%). Hepatic flexure growth was found in 1 (3%), descending colonic growth was found in 2 (6%), and 4 (13%) patients had transverse colon growth. The metagenomics analysis was carried out, and a total of 3.58G reads were sequenced, and about 321.91G data were used in the analysis. This study identified 11 genera specific to colorectal cancer patients when compared to genera in the control group. Bacteroides fragilis and Fusobacterium were found to be significantly prevalent in the carcinoma group when compared to the control group. CONCLUSION: The current study has given an insight into the microbiota of colorectal cancer patients in Saudi Arabia and has identified various genera significantly present in these patients when compared to those of the control group.

Efficacy of neutral and negatively charged liposome-loaded gentamicin on planktonic bacteria and biofilm communities.

We investigated the efficacy of liposomal gentamicin formulations of different surface charges against Pseudomonas aeruginosa and Klebsiella oxytoca. The liposomal gentamicin formulations were prepared by the dehydration-rehydration method, and their sizes and zeta potential were measured. Gentamicin encapsulation efficiency inside the liposomal formulations was determined by microbiologic assay, and stability of the formulations in biologic fluid was evaluated for a period of 48 h. The minimum inhibitory concentration and the minimum bactericidal concentration were determined, and the in vitro time kill studies of the free form of gentamicin and liposomal gentamicin formulations were performed. The activities of liposomal gentamicin in preventing and reducing biofilm-forming P. aeruginosa and K. oxytoca were compared to those of free antibiotic. The sizes of the liposomal formulations ranged from 625 to 806.6 nm in diameter, with the zeta potential ranging from -0.22 to -31.7 mV. Gentamicin encapsulation efficiency inside the liposomal formulation ranged from 1.8% to 43.6%. The liposomes retained >60% of their gentamicin content during the 48 h time period. The minimum inhibitory concentration of neutral formulation was lower than that of free gentamicin (0.25 versus 1 mg/L for P. aeruginosa and 0.5 versus 1 mg/L for K. oxytoca). The negatively charged formulation exhibited the same bacteriostatic concentration as that of free gentamicin. The minimum bactericidal concentration of neutral liposomes on planktonic bacterial culture was twofold lower than that of free gentamicin, whereas the negatively charged formulations were comparable to free gentamicin. The killing time curve values for the neutral negatively charged formulation against planktonic P. aeruginosa and K. oxytoca were better than those of free gentamicin. Furthermore, liposomal formulations prevent the biofilm-formation ability of these strains better than free gentamicin. In summary, liposomal formulations could be an effective lipid nanoparticle to combat acute infections where planktonic bacteria are predominant.

The emergence of a novel sequence type of MDR Acinetobacter baumannii from the intensive care unit of an Egyptian tertiary care hospital.

BACKGROUND AND AIM OF WORK: Acinetobacter baumannii is known for nosocomial outbreaks worldwide. In this study, we aimed to investigate the antibiotic susceptibility patterns and the clonal relationship of A. baumannii isolates from the intensive care unit (ICU) of an Egyptian hospital. METHODS: In the present study, 50 clinical isolates of multidrug resistant (MDR)-A. baumannii were obtained from patients admitted into the ICU from June to December 2015. All isolates were analyzed for antimicrobial susceptibilities. Multiplex PCR was performed to detect genes encoding oxacillinase genes (bla OXA-51-like, bla OXA-23-like, bla OXA-24-like, and bla OXA-58-like). Multilocus sequence typing (MLST) based on the seven-gene scheme (gltA, gyrB, gdhB, recA, cpn60, gpi, rpoD) was used to examine these isolates. RESULTS: All A. baumannii clinical isolates showed the same resistance pattern, characterized by resistance to most common antibiotics including imipenem (MIC ≥ 8µ/mL), with the only exception being colistin. Most isolates were positive for bla OXA-51-like and bla OXA-23-like (100 and 96%, respectively); however, bla OXA-24-like and bla OXA-58-like were not detected. MLST analysis identified different sequence types (ST195, ST208, ST231, ST441, ST499, and ST723) and a new sequence type (ST13929) with other sporadic strains. CONCLUSIONS: MDR A. baumannii strains harboring bla OXA-23-like genes were widely circulating in this ICU. MLST was a powerful tool for identifying and epidemiologically typing our strains. Strict infection control measures must be implemented to contain the worldwide spread of MDR A. baumannii in ICUs.

The occurrence of ESBL-producing Escherichia coli carrying aminoglycoside resistance genes in urinary tract infections in Saudi Arabia.

BACKGROUND: The infection and prevalence of extended-spectrum ß-lactamases (ESBLs) is a worldwide problem, and the presence of ESBLs varies between countries. In this study, we investigated the occurrence of plasmid-mediated ESBL/AmpC/carbapenemase/aminoglycoside resistance gene expression in Escherichia coli using phenotypic and genotypic techniques. METHODS: A total of 58 E. coli isolates were collected from hospitals in the city of Makkah and screened for the production of ESBL/AmpC/carbapenemase/aminoglycoside resistance genes. All samples were subjected to phenotypic and genotypic analyses. The antibiotic susceptibility of the E. coli isolates was determined using the Vitek-2 system and the minimum inhibitory concentration (MIC) assay. Antimicrobial agents tested using the Vitek 2 system and MIC assay included the expanded-spectrum (or third-generation) cephalosporins (e.g., cefoxitin, cefepime, aztreonam, cefotaxime, ceftriaxone, and ceftazidime) and carbapenems (meropenem and imipenem). Reported positive isolates were investigated using genotyping technology (oligonucleotide microarray-based assay and PCR). The genotyping investigation was focused on ESBL variants and the AmpC, carbapenemase and aminoglycoside resistance genes. E. coli was phylogenetically grouped, and the clonality of the isolates was studied using multilocus sequence typing (MLST). RESULTS: Our E. coli isolates exhibited different levels of resistance to ESBL drugs, including ampicillin (96.61%), cefoxitin (15.25%), ciprofloxacin (79.66%), cefepime (75.58%), aztreonam (89.83%), cefotaxime (76.27%), ceftazidime (81.36%), meropenem (0%) and imipenem (0%). Furthermore, the distribution of ESBL-producing E. coli was consistent with the data obtained using an oligonucleotide microarray-based assay and PCR genotyping against genes associated with ß-lactam resistance. ST131 was the dominant sequence type lineage of the isolates and was the most uropathogenic E. coli lineage. The E. coli isolates also carried aminoglycoside resistance genes. CONCLUSIONS: The evolution and prevalence of ESBL-producing E. coli may be rapidly accelerating in Saudi Arabia due to the high visitation seasons (especially to the city of Makkah). The health authority in Saudi Arabia should monitor the level of drug resistance in all general hospitals to reduce the increasing trend of microbial drug resistance and the impact on patient therapy.