Gram-positive Bacterial Isolates Research Articles

The Hidden Threat of Antimicrobial Resistance: A Case Study from A Private Hospital in Jordan

Antibiotic resistance is considered a widespread problem with global health implications, leading to increased patient morbidity and impacting the selection of effective antibiotics, consequently influencing patient recovery. This study aimed to assess antibiogram resistance patterns of bacterial records at the Islamic Hospital in Jordan using a retrospective study during the period 2020-2022. A total of 9369 samples obtained from different patients were cultured. Data were processed and analyzed with SPSS v.23.0. The results showed that 2841 (30.3%) samples were positive for bacterial infections. Microbial profiles of positive samples indicated the highest proportion for Escherichia coli, 39%, followed by Klebsiella pneumoniae 12% were the most frequent Gram-negative bacterial isolates, whereas Staphylococcus aureus 13% and Streptococcus pneumoniae 4% were the most common Gram-positive bacterial isolates. Interestingly, multidrug-resistant bacteria comprised 61.7% of the isolates. The percentage of multi-drug resistance in isolates of Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae was 68.7%, 73.1%, and 72%, respectively. Escherichia coli was most resistant to ampicillin (89%) and most sensitive to imipenem (100%). Klebsiella pneumoniae showed a 100% sensitivity to meropenem but 49% resistance to ceftriaxone. Pseudomonas aeruginosa was the most sensitive to amikacin and colistin (86% and 100%, respectively). Staphylococcus aureus isolates have resistance rates of 78% for ciprofloxacin, 35.6% for clindamycin and an overall resistance rate of 68.7%. These findings indicate multiple resistance for isolated bacteria. Therefore, antimicrobial resistance should be monitored continuously, and patients should be treated based on anti-microbial susceptibility tests.

Comprehensive evaluation of the antibacterial and antibiofilm activities of NiTi orthodontic wires coated with silver nanoparticles and nanocomposites: an in vitro study.

Fixed orthodontic appliances act as a niche for microbial growth and colonization. Coating orthodontic wires with antimicrobial silver nanoparticles (AgNPs) and nanocomposite was adopted in this study to augment the biological activity of these wires by increasing their antibacterial and antibiofilm properties and inhibiting bacterial infections that cause white spot lesions and lead to periodontal disease. Three concentrations of biologically synthesized AgNPs were used for coating NiTi wires. The shape, size, and charge of the AgNPs were determined. Six groups of 0.016 × 0.022-inch NiTi orthodontic wires, each with six wires, were used; and coated with AgNPs and nanocomposites. The antimicrobial and antibiofilm activities of these coated wires were tested against normal flora and multidrug-resistant bacteria (Gram-positive and Gram-negative bacterial isolates). The surface topography, roughness, elemental percentile, and ion release were characterized. AgNPs and nanocomposite coated NiTi wires showed significant antimicrobial and antibiofilm activities. The chitosan-silver nanocomposite (CS-Ag) coated wires had the greatest bacterial growth inhibition against both Gram-positive and Gram-negative bacteria. The surface roughness of the coated wires was significantly reduced, impacting the surface topography and with recorded low Ni and Ag ion release rates. NiTi orthodontic wires coated with AgNPs, and nanocomposites have shown increased antimicrobial and antibiofilm activities, with decreased surface roughness, friction resistance and limited- metal ion release.

The impact of the COVID-19 pandemic on pediatric bloodstream infections and alteration in antimicrobial resistance phenotypes in Gram-positive bacteria, 2020–2022

BackgroundAlteration in the etiology of pediatric bloodstream infections (BSIs) and antimicrobial resistance (AMR) is not well known during the Coronavirus disease 2019 (COVID-19) pandemic. This study aimed to investigate the impact of the COVID-19 pandemic on pediatric BSIs and alteration in antimicrobial resistance phenotypes in Gram-positive bacteria.MethodsThe frequency of BSIs among children under 18 years old was retrospectively recorded in a tertiary children’s hospital in Tehran, Iran from February 2020 to December 2022. The status of COVID-19 infection using reverse transcription polymerase chain reaction, bacteremia/fungemia according to BACTEC 9120 Culture System results, characterization of bacteria using biochemical tests, and antimicrobial susceptibility patterns for Gram-positive bacterial isolates using disk diffusion method were determined. Statistical analysis was done to measure the correlation of COVID-19 infection with BSIs and AMR.ResultsOut of 13,345 COVID-19 tests and 4,194 BACTEC blood culture requests, bacteremia/fungemia were confirmed in 10.37% (435/4,194) of the patients who requested both tests simultaneously. The COVID-19 infection was confirmed in 25.3% (110/435) of the patients with bacteremia/fungemia. The infection with characterized Gram-positive bacteria (GPB) and fungi was detected in 32.3% (140/433) and 8.31% (36/433) of the cases, respectively. Coagulase-negative Staphylococcus (CNS, 72, 16.62%), S. aureus (36, 8.3%), and Enterococcus spp. (22, 5%) were among the common isolates. Candida spp. and non-Candida yeasts were detected in 6.7% and 13.4% of the cases, respectively. A positive correlation was shown between the CNS bacteremia and COVID-19 infection (p-value = 0.019). Antibiotic susceptibility testing results showed the highest frequency of resistance to azithromycin among CNS, azithromycin and tetracycline among S. aureus and tetracycline among Enterococcus spp. Methicillin-resistance phenotype in the S. aureus (MRSA) and coagulase-negative Staphylococcus spp. (MR-CNS) was detected in 40% and 61.5% of the strains, respectively and the Enterococci were resistant to vancomycin in 33.3% of the isolates.ConclusionA decline in the trend of BSIs by GPB and an increase in AMR was shown in children during the COVID-19 pandemic. Increasing antibiotic resistance is a concern; however, chloramphenicol, linezolid, and vancomycin remain active against common causes of GPB-BSIs.

Study of Bacterial Contamination in the Operating Room and Newborn Intensive Care Unit: Effects of the Predominantly Used Antibiotics at Sabratha Teaching Hospital

Contamination by bacteria in the operating room (OR) and newborn intensive care units (NICU) has continued to increase the incidence of nosocomial infections and a center point of multidrug-resistant (MDR) pathogens. This study was to examine the spread of bacteria isolated from inanimate surfaces in the operating room and neonatal intensive care units at Sabratha Teaching Hospital and find out the effectiveness of the most antimicrobial used. Methods: At the Sabratha Teaching Hospital in Sabratha, Libya, a cross-sectional, descriptive study was conducted in the OR and NICU from February to May 2024. A total of 22 swab samples were collected from high-contact environmental surfaces. Isolation, identification, and antibiotic sensitivity patterns were performed via standard techniques. Results: After 48 hours of incubation, (54.5 %) of the swabbed surfaces showed positive bacterial growth and 45.5% showed no bacterial growth, of which 25% had gram-positive bacteria and 75% had gram-negative bacteria. Staphylococcus saprophyticus 3 (25%) was the identified gram-positive bacterial isolate, and Klebsiella spp. 5 (55.5%) and Pseudomonas aeruginosa 4 (44.4%) were the probable gram-negative bacterial isolates. The antimicrobial susceptibility pattern of clinical pathogens tested Staphylococcus epidermides and Klebsiella spp showed similar patterns which were sensitive to most antimicrobials used, while Pseudomonas aeruginosa was highly resistant to Cotrimoxazole, Cefatoxime, Cefixitin, Ceftazidime, Ceftricillin, and Calvu amoxicillin. Conclusion: This study confirms the need for rigorous disinfection protocols and hand hygiene to reduce the spread of these pathogens in the OR and NICU.

Production and biological activities of exopolysaccharides synthesized by thermophilic bacilli isolated from hot springs in Türkiye.

Thermophilic bacteria able to produce exopolysaccharides (EPSs) have become attractive in recent years. EPSs synthesized by thermophiles are worth investigating due to their unexplored structural and biological properties. In this study, EPSs from thermophilic, Gram-positive bacterial isolates were purified and tested for their biological activities. A total of one hundred seven thermophilic bacteria were screened for their ability to produce exopolysaccharides. Nine isolates belonging to Geobacillus, Parageobacillus, Aeribacillus, and Anoxybacillus genera with highest EPS production were chosen, and purified EPSs (20, 61, 74, 76, 78, 89, 106, 134, and 261) were used for biological activity studies. EPS yields of selected thermophilic bacteria ranged between 117 and 419mg/L. Among the tested EPSs, 61, 106, and 261 showed antibacterial effect against E. faecalis JH2-2 at a final concentration of 1.5mg/mL. EPS samples had significantantioxidant capacity, especially EPS 134, with the highest DPPH radical scavenging activity of 100% at a concentration of 5mg/mL and the strongest reducing power.EPS 20 showed the highest lipid peroxidation inhibition effect at a rate of 31%. EPSs displayed weak alpha-amylase inhibition activity when compared with standard acarbose. The prebiotic indices of EPSs 20, 61, 76, 89, 134, and 261 were found to be higher than that of inulin, a representative prebiotic carbohydrate for all tested lactic acid bacteria in the study. All examined EPSs inhibited the biofilms formed by various bacteria depending on the test strain. Results indicated that thermophilic EPSs had remarkable antioxidant, prebiotic, and antibiofilm activities. Therefore, EPSs characterized in this study may have technological applications in health and food fields.

Discovery of novel dihydropyrrolidone-thiadiazole compound crosstalk between the YycG/F two-component regulatory pathway and cell membrane homeostasis to combat methicillin-resistant Staphylococcus aureus

The rapid emergence and spread of multidrug-resistant (MDR) Gram-positive pathogens present a significant challenge to global healthcare. Methicillin-resistant Staphylococcus aureus (MRSA) is a particular concern because of its high resistance to most antibiotics. Based on our previously reported chemical structure of compound 62, a series of novel derivatives were synthesized and evaluated for their antibacterial activities. We found that some of these derivatives displayed effective antibacterial activity against Gram-positive pathogens, with minimal cytotoxicity (CC50>100 μM) and hemolytic activity (HC50>200 μM). Among these derivatives, the minimum inhibitory concentration (MIC) of 62-7c against Gram-positive bacterial isolates ranged from 6.25 to 25 μM. This derivative also exhibited significant synergistic antibacterial effects with daptomycin both in vitro and in vivo, with an ability to eradicate planktonic and persister cells of MRSA. Additionally, 62-7c inhibited biofilm formation and eradicated mature biofilms of MRSA. Mechanistic studies revealed that 62-7c inhibited the YycG kinase activity and disrupted the cell membrane by binding to cardiolipin (CL), leading to cell death. Importantly, no development of drug resistance was observed even after 20 serial passages. Furthermore, 62-7c exhibited high biosafety and potent effectiveness in combating infections in both mouse pneumonia and mouse wound models infected with MRSA. Thus, our study revealed that 62-7c has the potential to serve as a novel antibacterial agent for treating MRSA infections.

Magnitude and antimicrobial susceptibility profile of bacteria isolated from pediatric sepsis cases at University of Gondar Hospital, Northwest Ethiopia

BackgroundSepsis is one of the major causes of morbidity and mortality among pediatric patients throughout the world. The varying microbiological pattern of sepsis warrants the need for researches on the causative organisms and their antimicrobial susceptibility pattern. The epidemiology of neonatal and pediatric sepsis in Ethiopia is under-research. The objective of this study was to evaluate the burden of bacterial pathogens and their antimicrobial susceptibility patterns among children suspected of sepsis.MethodsAn institutional-based prospective cross-sectional study was conducted on 370 pediatric(age birth-15 years) patients suspected of sepsis at the University of Gondar Comprehensive Specialized hospital from December 2020 to November 2021. Blood samples were collected aseptically and inoculated into Tryptone Soya Broth for culture. The organisms grown were identified by standard microbiological methods and subjected to antibiotic susceptibility testing by modified Kirby-Bauer disk diffusion method recommended by Clinical laboratory and standard institute. Methicillin resistance was confirmed using Cefoxitin disk diffusion method. Data entry and analysis were done using Statistical Package for Social Sciences (SPSS) version 26 software. A p-value less than 0.05 at 95% confidence interval was considered statically significant.ResultsOut of the total 370 study subjects, 21.6% (80/370) of them were culture positive. Of these, 43 (53.8%) and 37 (46.3%) were Gram-positive and Gram-negative bacterial pathogens, respectively. The most prevalent Gram-positive bacterial isolate was Staphylococcus aureus (n = 24; 30%) and coagulase negative staphylococci (n = 7; 8.8%). Among the Gram-negative bacterial isolates, the leading bacteria was Klebsiella pneumoniae (n = 20; 25%) followed by Escherichia coli (n = 7; 8.8%). Clindamycin, Chloramphenicol, Gentamicin and Ciprofloxacin were the most effective antibiotics against Gram-positive bacterial isolates while Amikacin, Meropenem and Chloramphenicol were effective against Gram-negative pathogens. Methicillin resistance was detected in 45.8% of Staphylococcus aureus. Multi-drug resistance (MDR) antimicrobial susceptibility pattern was observed in 76% of the bacterial isolates.ConclusionGram positive bacteria were the predominant isolates among pediatric sepsis cases and most of the bacterial isolates showed MDR. Staphylococcus aureus and Klebsiella pneumoniae were frequently isolated bacteria. The high prevalence of drug resistance warrants rational use of antibiotics and the need for regular antibiotic susceptibility surveillance studies.

Isolation of Multi-drug Resistant Bacteria from Patients Admitted to Aljala Trauma Hospital in Benghazi, Libya

Abstract Background: The high prevalence of multidrug-resistant (MDR) bacteria is a worldwide problem. The overuse and misuse of antimicrobial agents favored the emergence of MDR bacteria and rendered infectious agents difficult to treat. The aim of this study was to isolate bacteria responsible for wound infections in inpatients and outpatients treated at Aljala Trauma Hospital, Benghazi, Libya. Methods: A cross-sectional study was conducted at Al-Jala Trauma Hospital from January to July 2019. Wound swab samples were collected from 230 patients and cultured on different media. An antibiogram of isolates was determined. We were using the disk diffusion technique (Kirby-Bauer technique). Results: Three hundred fifty-five isolates were able to grow on culture media. A single etiological agent was identified in 149 patients and multiple agents were found in 81 patients. The predominant pathogens isolated were Pseudomonas aeruginosa and Staphylococcus aureus (21%), E. coli (15%) Klebsiella (14%), Acinetobacter (7%), CoNS and Enterobacter (6%), while Enterococcus sp. (4%), proteus sp. (3%) and S. pyogens(1%) The overall MDR among Gram-positive and Gram-negative bacterial isolates were (32.7%) and (67.3%) respectively. The percentage of MRSA was 16%, surprisingly the prevalence of MDR among Pseudomonas aeruginosa, Acinetobacter sp., Proteus sp., and S. pyogens were very high (100%) and most of the other bacteria isolated were resistant to most of the antibiotics used. Moreover, Co-negative isolates appeared highly resistant to Oxacillin (89%), Enterococcus sp. (90%), and Staph aureus sp. (79%) Conclusion: The prevalence of multi-drug resistance among Gram-positive and Gram-negative bacteria is high and this is considered a serious problem. It is necessary to follow the bio gram of bacteria causing wound infections in the hospital as this would be beneficial to patients as well as help physicians in the selection of appropriate treatment. Moreover, aseptic techniques, hand hygiene, and wearing personal protective equipment will improve patient outcomes and help reduce the spread of pathogens among patients and in the hospital.

Isolation and study of plant growth promoting rhizobacteria from Triticosecale Wittmack growing in Almaty region

This article presents data on isolation and characterization of native plant growth-promoting rhizobacteria (PGPR) from the rhizosphere and root-endosphere of X Triticosecale Wittmack growing in Almaty region. A total of 22 distinct (eighteen gram-negative and four gram-positive) bacterial isolates were identified, classified according to their spore-forming activity: eighteen non-spore-forming and four spore-forming bacteria. Bacterial isolates were screened in vitro for PGPR characteristics and evaluated for their beneficial effects on the early growth of triticale variety X Triticosecale Wittmack. The findings of our research indicated isolation of four growth-promoting bacteria (AS4, AS6, AR1, TS6), three antifungal bacteria (AR2 and AS7), and one strain of combined action, i.e. high growth-promoting and fungistatic activity (AR6). Research has demonstrated that PGPR can be utilized as biofertilizers for crop production. Study marks the beginning of a larger investigation into the bacterial diversity of the triticale variety X Triticosecale Wittmack in the Almaty region.

In vitro antibacterial activity of Bersama abyssinica Fresen crude extract against representative Gram-positive and Gram-negative bacterial isolates.

Bersama abyssinica Fresen is a plant that is used in folk medicine for the treatment of mastitis and other infectious diseases. The antibacterial activity of methanol crude extract of plant was evaluated against three common bacterial pathogens, including Gram positive (Staphylococcus aureus) and Gram negative (Escherichia coli and Pseudomonas aeruginosa). The antibacterial activities and minimum inhibitory concentration of B. abyssinica crude extracts were evaluated using agar-well diffusion and broth dilution methods according to the National Committee for Clinical Laboratory Standards (NCCLS). A significant difference in the antibacterial activity of crude extracts was observed among different levels of concentration against tested isolates. A higher mean inhibition zone diameter was recorded in E. coli (29.2 ± 1.5mm), followed by S. aureus (27.8 ± 1.1mm) and P. aeruginosa (18.0 ± 0.7mm) at a concentration of 100mg/mL. The antibacterial activity of crude plant extract at 100mg/mL was comparable with that of a standard antibiotic (27.6 ± 2.6) against S. aureus and E. coli isolates. The findings indicated that bacterial growth inhibition increased as the concentration of the crude extracts increased. E. coli and S. aureus isolates showed significantly higher susceptibilities to crude extracts than P. aeruginosa at all concentrations. The minimum inhibitory concentrations of extracts against S. aureus, E. coli and P. aeruginosa isolates were 0.78mg/mL, 1.56mg/mL and 1.56mg/mL, respectively. All tested pathogenic bacterial species were susceptible to plant leaf extract and broad-spectrum activity against Gram-positive and Gram-negative bacteria. The study recommends further fractionation of the B. abyssinica plant that contributes to its antibacterial activity and understands the mode of action of this plant against bacteria and other microbes.

Evaluation of In vitro Anticancer Activity (Ovarian Cancer Cells-pa1) and Zebrafish Embryo Toxicity of Parmelia perlata Ethanolic Extract

The Phytochemical composition and bioactivity of an ethanolic extract of Parmelia perlata were analyzed in this study using established procedures. The extract revealed a rich array of phytochemicals, showcasing its diverse composition, and notably exhibited strong antioxidant activity according to the 1, 1-diphenyl-2- picrylhydrazyl (DPPH) test. Furthermore, the research explored the extract’s potential in preventing Bovine Serum Albumin (BSA) denaturation, comparing it with the well-known medication Diclofenac. The concentration-dependent inhibition of BSA denaturation by P. perlata ethanolic extract was comparable to the effects observed with diclofenac on BSA. The ethanolic extract demonstrated concentration-dependent antibacterial activity against gram-negative and gram-positive bacterial isolates. While gentamicin served as a positive control with larger zones of inhibition, P. perlata extract displayed significant antibacterial efficacy against all six tested organisms. Moreover, in vitro testing against human ovarian (PA-1) cell lines demonstrated the extract’s anticancer potential. A concentration-dependent reduction in cell viability, culminating in the lowest percentage at 1000 µg/ml, was observed. The IC50 value of 31.2 µg/mL showed that the P. perlata extract strongly inhibited the PA-1 cell line. This was confirmed by the observed changes in the cellular morphology when exposed to higher concentrations of the extract. Further, the ethanolic extract of P. perlata was subjected to various concentrations to evaluate its embryotoxicity on zebrafish embryos. The concentration of extract was determined to have a safety limit of less than 50 µg/L. In summary, P. perlata ethanolic extract has emerged as a promising natural resource, exhibiting a spectrum of bioactivities, including potent antioxidant, anti-inflammatory, antibacterial, anticancer properties, and embryonic toxicology study. These findings suggest that its potential utility in pharmaceutical applications is warranted, and further exploration and development are being suggested.

Diversity and Bioprospection of Gram-positive Bacteria Derived from a Mayan Sinkhole

Water-filled sinkholes known locally as cenotes, found on the Yucatán Peninsula, have remarkable biodiversity. The primary objective of this study was to explore the biotechnological potential of Gram-positive cultivable bacteria obtained from sediment samples collected at the coastal cenote Pol-Ac in Yucatán, Mexico. Specifically, the investigation aimed to assess production of hydrolytic enzymes and antimicrobial compounds. 16 S rRNA gene sequencing led to the identification of 49 Gram-positive bacterial isolates belonging to the phyla Bacillota (n = 29) and Actinomycetota (n = 20) divided into the common genera Bacillus and Streptomyces, as well as the genera Virgibacillus, Halobacillus, Metabacillus, Solibacillus, Neobacillus, Rossellomorea, Nocardiopsis and Corynebacterium. With growth at 55ºC, 21 of the 49 strains were classified as moderately thermotolerant. All strains were classified as halotolerant and 24 were dependent on marine water for growth. Screening for six extracellular hydrolytic enzymes revealed gelatinase, amylase, lipase, cellulase, protease and chitinase activities in 93.9%, 67.3%, 63.3%, 59.2%, 59.2% and 38.8%, of isolated strains, respectively. The genes for polyketide synthases type I, were detected in 24 of the strains. Of 18 strains that achieved > 25% inhibition of growth in the bacterial pathogen Staphylococcus aureus ATCC 6538, 4 also inhibited growth in Escherichia coli ATCC 35,218. Isolates Streptomyces sp. NCA_378 and Bacillus sp. NCA_374 demonstrated 50–75% growth inhibition against at least one of the two pathogens tested, along with significant enzymatic activity across all six extracellular enzymes. This is the first comprehensive report on the biotechnological potential of Gram-positive bacteria isolated from sediments in the cenotes of the Yucatán Peninsula.

Bacterial profile, drug resistance pattern, clinical and laboratory predictors of ascites infection in cirrhosis patients

Ascites is a pathological collection of free fluid in the peritoneal cavity, which is a common complication in patients with cirrhosis, an advanced liver disease. Bacterial infection increases the mortality rate of hospitalized patients with cirrhosis, irrespective of the severity of the liver disease. Around 60% of patients with compensated cirrhosis developed ascites within 10 years during the course of their disease. The in-hospital mortality rate due to spontaneous bacterial peritonitis (SBP) could exceed 90%, but with early diagnosis and prompt antibiotic therapy, this rate has been shown to decrease to 20%. Here, we enrolled adult (age ≥ 18) patients with liver disease with evidence of cirrhosis who developed ascites and assessed the presence of spontaneous ascites fluid infection (SAFI) in these patients. Of the total 218 patients, 22.9% (50/218) develop ascites infection. The liver organ function tests like alanine aminotransferase, aspartate aminotransferase, total bilirubin, and direct bilirubin were found to be significantly (P < 0.05) higher in patients with ascites fluid infection compared to patients with non-ascites fluid infection. Of the gram-negative bacteria, K. pneumonia and E. coli were isolated and found to be 100% resistant to amoxicillin and clavulanate. From the gram-positive bacterial isolates, S. aureus was only resistant to penicillin, whereas Str. viridans was resistant to ceftriaxone, cefotaxime, cefepime, and penicillin. On the other hand, clinical features such as a history of jaundice, low arterial blood pressure, and ultrasound results such as a shrunken liver and enlarged spleen were also independent predictors of spontaneous bacterial peritonitis. In conclusion, given the high probability of death following SAFI, early detection, and treatment, as well as knowledge of the microbial agent, resistance profile, and predictive markers in various contexts, are essential for the timely diagnosis and management of SAFI in these patients.

Antibiotic Susceptibility Profiling of Gram-Positive and Gram-Negative Bacterial Isolates in a Tertiary Care Hospital: Establishment of an Antibiogram.

Introduction Antimicrobial resistance poses a significant global healthcare challenge in the management of bacterial infections, which is frequently attributed to rapid bacterial adaptations. This study aims to develop an antibiogram for a tertiary care hospital, providing comprehensive antibiotic sensitivity profiles for Gram-positive and Gram-negative bacteria. It informs healthcare providers of antibiotic resistance trends, enabling informed treatment decisions and enhanced infection control measures. Methods We conducted a six-month prospective observational study, during which we gathered and analyzed data from the microbiology laboratory to identify patterns of antimicrobial sensitivity. Subsequently, the data underwent analysis and interpretation using the respected WHONET software, a readily available tool designed for this specific task. Our methodology adhered to the guidelines established by the Clinical & Laboratory Standards Institute for the standardization of antibiogram generation procedures, and these guidelines are easily integrated into the WHONET software for analytical purposes. Results There were a total of 357 isolates across various hospital departments, comprising 13 distinct bacterial species. Among them, nine were identified as Gram-negative bacteria, accounting for 262 (73.3%) isolates. Escherichia coli accounted for 131 (36.6%) isolates, while Klebsiella accounted for 62 (17.3%), emerging as the predominant species among them. The remaining four bacterial species were identified as Gram-positive bacteria, totaling 95 (26.6%) isolates, with Staphylococcus aureus being the most frequently isolated species at 51 (14.2%), followed by Enterococcus at 26 (7.2%). Subsequent analysis using the WHONET software facilitated the creation of an antibiogram. Among the Gram-negative bacteria, E. coli displayed high sensitivity (100%) to aztreonam and clindamycin, followed by nitrofurantoin (98%), imipenem (94%), and meropenem (95%). However, it exhibited decreased sensitivity to ampicillin (25%), cefuroxime (34%), and ceftriaxone (39%). Conversely, among the Gram-positive bacteria, S. aureus demonstrated 100% sensitivity to ampicillin, amoxiclav, cefazolin, teicoplanin, linezolid, rifampicin, nitrofurantoin, and cefotaxime. However, it exhibited zero sensitivity to vancomycin and only 6% sensitivity to cotrimoxazole. Conclusion This study advances the understanding of antibiotic susceptibility in a tertiary care setting and provides an invaluable tool for optimizing treatment strategies, enhancing infection control measures, and combating antibiotic resistance.

Gram Positive Cocci Associated Urinary Tract Infections, their Prevalence and Antibiotic Susceptibility Patterns

Background: Urinary tract infections (UTIs) are the third most common type of infection in humans globally. Gram-positive bacteria are said to be responsible for ten percent of urinary tract (UTI) infections. The study's goal was to profile gram-positive cocci-associated UTIs and their antibiogram, as they were observed at LASUTH. Methods: This was a retrospective assessment of the Medical Microbiology Laboratory records of the LASUTH to review the in vitro antibiotic susceptibility patterns of gram-positive urinary bacterial isolates between April 2020 and March 2021. The bacteria were isolated and identified from routine urine samples using standard bacteriological methods and the API. In vitro antibiotic susceptibility test (AST) was routinely performed by the modified Kirby-Bauer disk diffusion test and susceptibility breakpoints were determined using the Clinical and Laboratory Standards Institute (CLSI) guidelines. Results: 2,253 urine samples were processed in the medical microbiology laboratory over the one year and 662 (29.4%) samples yielded Positive cultures. Of the 662 isolates, 494 (74.6%) were gram-negative bacteria. 164 (24.8%) were gram-positive cocci while 4 (0.6%) were gram positive rod. Among the gram-positive cocci’s isolated Enterococcus faecalis had the highest frequency 58 (35.4%). Aminoglycosides (Gentamycin and Amikacin) and Linezolid antibiotics were found to be the most effective drugs against gram-positive cocci bacteria except Enterococcus spp. For empirical treatment of Enterococcus spp in our facility Fosfomycin and Tigecycline are the best options, while for Streptococcus agalactiae associated UTI, Amikacin, Cefuroxime, Linezolid, and levofloxacin can be used for empirical treatment. Conclusion: The prevalence rate of gram-positive cocci associated UTI in this study was 7.3% (164/2253). The emergence of drug resistance in these pathogens to commonly used antibiotics is a thing of concern. Therefore, efficient antimicrobial stewardship programmes must be in place.

Antibacterial, Anti-Biofilm, and Anti-Inflammatory Properties of Gelatin-Chitosan-Moringa-Biopolymer-Based Wound Dressings towards Staphylococcus aureus and Escherichia coli.

In contemporary times, the sustained aspiration of bioengineering and biomedical applications is the progressive advancement of materials characterized by biocompatibility and biodegradability. The investigation of the potential applications of polymers as natural and non-hazardous materials has placed significant emphasis on their physicochemical properties. Thus, this study was designed to investigate the potential of gelatin-chitosan-moringa leaf extract (G-CH-M) as a novel biomaterial for biomedical applications. The wound-dressing G-CH-M biopolymer was synthesized and characterized. The blood haemolysis, anti-inflammatory, antioxidant, and antibacterial activities of the biopolymer were investigated against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacterial isolates. Our results showed that S. aureus swarming motility was drastically affected. However, the biopolymer had no significant effect on the swarming motility of E. coli. In addition, the biopolymer showed high antibacterial capacities, especially against S. aureus. Plasmid DNA was observed to be effectively protected from oxidative stresses by the biopolymer. Furthermore, the biopolymer exhibited greatly suppressed haemolysis (lower than 2%), notwithstanding the elevated concentration of 50 mg/mL. These results indicated that this novel biopolymer formulation could be further developed for wound care and contamination prevention.

Antimicrobial profiling of mastitis causing bacteria in buffalo milk

Mastitis is causing huge economic losses to the dairy industry in India. The losses were mainly due to decreased milk production and treatment cost. This study was aimed to detect occurrence of mastitis in buffaloes. A total of 5,665 milk samples from buffaloes were processed for detection of mastitis by white side test (n=4,884) and culture examination (n=781). Overall, 2,808 (57.49%) milk samples were positive by white side test and 96.79% (n=756) samples were found positive by culture examination. Gram-positive and gram-negative bacteria were detected in 54.16% (n=423) and 31.11% (n=243) of the milk samples, respectively. Mixed infection of both was found in 10.62% (n=83) samples. While, Candida spp. was detected in 0.89% (n=7) samples only. Antibiotic sensitivity assay revealed that chloramphenicol was the most sensitive antibiotic against 71.61% samples in both gram-positive and negative bacterial isolates followed by enroloxacin, amikacin, levofloxacin, moxifloxacin and gentamicin in 71.09%, 61.77%, 58.85%, 58.59% and 55.99% samples, respectively. Kanamycin was most resistant against all isolates followed by neomycin (76.36%), norfloxacin (60.99%), amoxicillin+cloxacillin (52.78%), and ceftizoxime (51.85%).

Antibacterial Effect of Nigerian Honey on Staphylococcus aureus and Escherichia coli

Background: Honey exhibits antimicrobial activities against a wide range of bacteria in different milieu. Objective: To determine the antibacterial effect of Nigerian honey types on selected bacterial isolates; Staphylococcus aureus and Escherichia coli. For this reason raw and commercial honey samples were investigated.Methods: Two honey samples were used in this study sourced from two different institutions: raw (sunshine) and commercial (shoprite; Labsan) honey. They were tested on clinically selected Grampositive and Gram-negative bacterial isolates: Staphylococcus aureus and Escherichia coli respectively.Results: The honey samples examined were effective in inhibiting the growth of the test bacteria and the inhibitory effects were found to be superior from sunshine honey on Staphylococcus aureus. Among the selected bacteria used in this assay, Staphylococcus aureus was the most susceptible to the honey samples used and sunshine (raw) honey was found more effective.Conclusion: The Nigerian honey types used in this study were found to be alternative natural antibiotic to conventional synthetic antibiotics.International Journal of Human and Health Sciences Vol. 08 No. 01 Jan’24 Page: 65-68

Real-World Use of Dalbavancin for Treatment of Soft Tissue and Bone Infection in Children: Safe, Effective and Hospital-Time Sparing.

Acute bacterial skin and skin structure infections (ABSSSI) and osteoarticular infections compound the burden of morbidity, mortality and prolonged hospitalizations among gram-positive infections. Dalbavancin, a second-generation, intravenous lipoglycopeptide, due to its prolonged half-life, can be a valuable alternative in their treatment when administered as inpatient treatment at the price of an extended hospital stay. Between October 2019 and September 2023, 31 children and adolescents were treated with dalbavancin because of bone and joint infections (n = 12 patients, 39%), ABSSSI (n = 13 patients, 42%), mainly for the limbs, facial cellulitis or complicated ABSSSI (n = 6 patients, 19%), at five Italian pediatric centers. Microbiological study provided gram-positive bacterial isolate in 16 cases, in 11 cases from a positive blood culture; 9 of them were MRSA. Twenty-five patients were initially treated with a different antibiotic therapy: beta-lactam-based in 18 patients (58%), glycopeptide-based in 15 patients (48%) and daptomycin in 6 (19%). The median time that elapsed between admission and start of dalbavancin was 18 days. A total of 61 doses of dalbavancin were administered to the 31 patients: 16 received a single dose while the remaining 15 patients received between two (n = 9) and nine doses. The frequency of administration was weekly in five cases or fortnightly in nine patients. Median length of stay in hospital was 16 days. Median time to discharge after the first dose of dalbavancin was 1 day. Treatment was very well-tolerated: of the 61 administered doses, only four doses, administered to four patients, were associated with an adverse event: drug extravasation during intravenous administration occurred in two patients, with no sequelae; however, in two patients the first administration was stopped soon after infusion start: in one (ID #11), due to headache and vomiting; in another (ID #12) due to a systemic reaction. In both patients, drug infusion was not repeated. None of the remaining 29 patients reported treatment failure (resistant or recurrent disease) or an adverse effect during a median follow-up time of two months. The use of dalbavancin was safe, feasible and also effective in shortening the hospital stay in children and adolescents.

Current Status of Drug-resistant Patterns of Gram-positive Clinical Isolates Collected from Renowned Diagnostic Centers of Dhaka, Bangladesh

Background: Antimicrobial resistance is a serious concern and life threat in public health globally. Gram-positive clinical isolates are one of the leading etiological agents showing drug resistance traits. This study aimed to detect the antimicrobial resistance pattern of clinically isolated Gram-positive bacterial isolates collected from various renowned diagnostic centers of Dhaka city, Bangladesh. Methods: A laboratory-based cross-sectional study was conducted at the Microbiological Laboratory of the Department of Microbiology, Stamford University Bangladesh. A total of 104 clinical specimens (wound swab, pus, blood, urine, ear discharge, nasal swab, sputum, nipple discharge, breast milk, catheter tip, umbilical swab, and throat swab) from different age groups were collected from some renowned diagnostic centers of Dhaka city for analyzing the cultural and drug sensitivity patterns from January 2023 to April 2023. According to the study plan, only the Gram-positive bacteria were collected and transported to the laboratory of the Department of Microbiology, Stamford University Bangladesh following WHO guidelines, and the antimicrobial susceptibility tests were carried out by Kirby–Bauer disk diffusion method and the results were interpreted as per CLSI guidelines, 2022. Results: This study highlights the presence of Staphylococcus aureus (65.4%), Streptococcus spp. (23.1%), and Enterococcus spp. (11.5%) as causative agents of Gram-positive bacterial infections from overall 104 clinical specimens. Most of our isolates were found multidrug-resistant. For S. aureus isolates, cefixime (100%); for Streptococcus spp., doxycycline (95.83%); and for Enterococcus spp., amoxicillin (100%), cefixime (100%), colistin (100%), and cotrimoxazole (100%) were found to be the most ineffective drug when compared to other antibiotics. Conclusion: Our study portrayed the remarkable antibiotic resistance feature of Gram-positive bacterial isolates which is a matter of public health concern. It is necessary to carry out a continuous assessment of antibiotic sensitivity patterns of resistant Gram-positive bacteria; otherwise, it will become an uncontrollable problem not only in Bangladesh but also worldwide in the near future.