Antibacterial Susceptibility Testing Research Articles

Comparative Study of Antimicrobial Efficacy and Phytochemical Profiles of Ethanol and n-Hexane Extracts from the Roots of Ixora coccinea Linn

The root extracts of Ixora coccinea were evaluated for their phytochemical composition, antibacterial activity, and minimum inhibitory concentration (MIC) against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. Quantitative phytochemical analysis was conducted to determine the levels of terpenoids, flavonoids, alkaloids, tannins, and saponins. Thin Layer Chromatography (TLC) was used to confirm the presence of bioactive components in the extracts under different solvent systems, followed by antibacterial susceptibility tests using the disc diffusion method. The MIC was determined through serial dilution to identify the lowest concentration that inhibited bacterial growth. Quantitative phytochemical analysis showed that the ethanol extract contained 14.80% flavonoids, 6.00% alkaloids, 1.20% saponins, 1.80% terpenoids, and 0.03% tannins. In contrast, the n-hexane extract had higher terpenoid content (3.40%) but lower flavonoids (5.20%) and alkaloids (2.10%). Thin Layer Chromatography (TLC) analysis under varying solvent systems showed different Rf values, with the ethanol extract displaying more diverse spots, indicating a richer variety of bioactive compounds. Antibacterial susceptibility tests revealed that the ethanol extract produced larger inhibition zones (10 ± 0.4–28 ± 1.0 mm) than the n-hexane extract (6 ± 0.2–26 ± 0.8 mm). MIC results indicated that ethanol extract inhibited E. coli and S. aureus at 50 mg/L and B. subtilis at 25 mg/L, while the n-hexane extract required 100 mg/L for effective inhibition. In conclusion, the findings indicate that the plant possesses significant antibacterial potential, warranting further research to isolate and characterize the specific phytoconstituents responsible for the observed antimicrobial activities.

Odontites linkii subsp. cyprius Ethanolic Extract Indicated In Vitro Anti-Acanthamoeba Effect.

This study aims to investigate three endemic ethanolic leaf extracts from Cyprus for anti-Acanthamoeba activities: Odontites linkii subsp. cyprius (Boiss.) Bolliger, Ptilostemon chamaepeuce subsp. cyprius (Greuter) Chrtek & B. Slavík, and Quercus alnifolia Poech. Screening for radical scavenging activity, total phenolic content (TPC), and total flavonoid content (TFC) were performed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABST) methods, Folin-Ciocalteu method, and aluminum chloride method, respectively. An antibacterial-susceptibility test (AST) was performed using a broth microdilution assay to estimate the minimum inhibitory concentration (MIC) using iodonitrotetrazolium chloride (INT). Trypan blue (0.5%) was used to assess in vitro anti-Acanthamoeba cell viability of the ethanolic leaf extracts after 24-, 48-, and 72-h exposure-screening of ethanolic leaf extracts with liquid chromatography-mass spectrometry (LC-MS) for known compounds with biological activity. The ethanolic leaf extract of Odontites linkii subsp. cyprius demonstrated the highest anti-Acanthamoeba activity, with an inhibitory concentration (IC50) of 7.02 mg/mL after 72 h. This extract also showed an in vitro minimum inhibitory concentration (MIC) of 0.625 mg/mL against Enterococcus faecalis, a common nosocomial pathogen. The LC-MS analysis revealed the presence of bioactive iridoid compounds in O. linkii subsp. cyprius, further highlighting its potential as a source for new drug compounds. The ethanolic extract of O. linkii subsp. cyprius demonstrated a dose-dependent and time-dependent anti-Acanthamoeba effect in vitro. This study is the first to report the presence of iridoid compounds and anti-Acanthamoeba activities in the ethanolic extract of O. linkii subsp. cyprius. These promising findings highlight the potential of plant extracts, particularly O. linkii subsp. cyprius, as a source for new drug compounds for Acanthamoeba infections.

Multitarget Phytocomplex: Focus on Antibacterial Profiles of Grape Pomace and Sambucus ebulus L. Lyophilisates Against Extensively Drug-Resistant (XDR) Bacteria and In Vitro Antioxidative Power.

Objectives: This study was conceived with the aim of translating the experience and knowledge of the research group into the design and creation of multi-active phytocomplex cocktails from lyophilised winery by-products (Grape Pomace-GP) and weeds (Sambucus ebulus L., Dwarf Elder-DE). Methods: Quantification of bioactive molecules was performed by high-performance liquid chromatography (HPLC) method. Results: In the extract obtained from lyophilised GP, the most dominant component that was quantified was petunidin-3-glucoside. Prominent compounds that were quantified in DE extract were cyanidin derivatives. The total number of microorganisms in lyophilisates is low, but some of them still survive lyophilisation. Antibacterial activity was determined by microdilution, the minimum inhibitory concentration (MIC) of the tested bacteria ranged from 0.78 mg/mL to 25.00 mg/mL. Antibacterial susceptibility testing (AST) revealed that Klebsiella spp. and Acinetobacter baumannii complex are extensively drug-resistant (XDR). Conclusions: The GP + DE cocktail showed very strong AB power against both tested XDR bacteria. The total phenolic content and antioxidative effect (determined spectrophotometrically) indicate their linear correlation.

Etiology of nosocomial infections and antibiotic resistance (level of antibiotic resistance) of identified pathogens in patients with traumatic chest injuries

Background. Chest injuries and wounds are common during armed conflicts, with frequent nosocomial infections and mortality up to 35-45% [1-4]. Infectious complications associated with multidrug-resistant microorganisms are an urgent issue in the management of patients with trauma. Aim. To conduct a retrospective review of the main causative agents of infectious complications in patients with traumatic chest injuries and evaluate antibiotic resistance of isolated pathogens. Materials and methods. Samples for microbiological examination were obtained from 160 patients with chest trauma and nosocomial complications. The samples included sputum, pleural fluid, bronchial washings obtained by fiberoptic bronchoscopy, and tracheal secretions. Antibacterial susceptibility tests were performed, and the antibiotic resistance mechanisms in isolated microorganisms were determined. Results. Gram-negative pathogens accounted for 93% of cases. The following organisms prevailed: Klebsiella pneumoniae – 42%, Acinetobacter baumannii – 28%, Pseudomonas aeruginosa – 18%, Escherichia coli – 9%. Of note, 91.4% of K. pneumoniae strains produced extended-spectrum β-lactamases and carbapenemases. The percentage of multidrug-resistant and pandrug-resistant strains was 48.2% and 52%, respectively. Conclusion. The data obtained indicate a wide spread of gram-negative microorganisms and their multiple resistance in patients with traumatic breast injuries complicated by nosocomial infection.

Nasal Carriage of Staphylococcus aureus and its Antibacterial Susceptibility Profiles among Food Handlers in Sana’a Restaurants, Yemen

Background: Staphylococcus aureus is a ubiquitous organism that normally colonizes the human body and causes food poisoning. This study aimed to determine the rate of nasal carriage of S. aureus among food handlers in Sana’a restaurants in, Yemen and performed an antibacterial susceptibility test. Methods: This cross-sectional study was carried out among healthy food handlers from November 2022 to March 2023. Approximately 024 nasal swabs were collected and S. aureus was isolated and identified according to standard bacteriological procedures. Moreover, the antibacterial susceptibility pattern was determined using the disc diffusion method. Additionally, the required data were obtained by using the pretested questionnaire. Results: Of 420 nasal swabs, 78 (18.6%) food handlers were S. aureus nasal carriers. The prevalence rate of S. aureus was significantly higher among subjects aged >30 years (23.1%), males (18.8%), and uneducated subjects (25%). Additionally, a higher rate of S. aureus nasal carriers was observed among food handlers who worked as cooks (19.4%), had less than 2 years of experience (20.5%), and had low hygiene (29%). The S. aureus isolates were sensitive to ciprofloxacin (71.8%), vancomycin (76.9%), and amoxicillin-clavulanic acid (61%). Conversely, the isolated S. aureus was resistant to oxacillin (69.2%) and methicillin (66.7%). Conclusion: These data stress that food handlers with a high S. aureus nasal carrier rate may pose significant risks to consumers. Therefore, creating restaurant policies and rules is necessary to provide safe and healthy food to consumers.

Incidence and Antibiotic Resistance Patterns of Staphylococcus aureus and Pseudomonas aeruginosa Isolated from Fomites in Critical Units of General Hospital Katsina

Study’s Excerpt Investigation of the role of fomites in the transmission of nosocomial pathogens, specifically Staphylococcus aureus and Pseudomonas aeruginosa, within various units of General Hospital Katsina was carried out. The results reveal high contamination of fomites in the male ward, with significant bacterial colony counts, and the differing susceptibility profiles of S. aureus and P. aeruginosa to commonly used antibiotics. There is need for improved infection control and antibiotic stewardship in the region. Full Abstract Nosocomial infections, predominantly caused by Staphylococcus aureus and Pseudomonas aeruginosa, continue to be a major public health challenge, especially in developing countries, due to their associated morbidity and mortality. This study aimed to isolate and identify bacterial pathogens from fomites in the Accident and Emergency (A&E) unit, male ward, and female ward of General Hospital Katsina and to evaluate their antimicrobial susceptibility patterns. A total of 90 swab samples were collected from frequently touched items such as beddings, door handles, floor surfaces, scissors, and forceps across the three locations. Standard microbiological techniques were utilized for the isolation and identification of S. aureus and P. aeruginosa, followed by antibacterial susceptibility testing using the disc diffusion method. Bacterial growth was observed in 58 (64.4%) samples, with S. aureus accounting for 32 (55.2%) and P. aeruginosa for 26 (44.8%) of the isolates. The male ward exhibited the highest contamination levels, with a mean colony count of 725.25 CFU/plate, significantly higher than the female ward (487.67 CFU/plate) and the A&E unit (48 CFU/plate), as confirmed by a one-way ANOVA (p < 0.05). Chi-square analysis revealed no statistically significant association between bacterial species and hospital location (p = 0.823). The susceptibility testing showed that S. aureus isolates were generally susceptible to Gentamycin, Ciprofloxacin, and Pefloxacin but resistant to Amoxicillin. Conversely, P. aeruginosa displayed high resistance to Gentamycin and Septrin. Conclusively, these findings revealed the critical role of fomites in the transmission of pathogens and highlighted the need for enhanced infection control measures and targeted antibiotic stewardship programs to mitigate the risks associated with these infections.

Antibacterial activity of a silver-incorporated vancomycin-modified mesoporous silica against methicillin-resistant Staphylococcus aureus.

Since conventional antibiotics are almost ineffective on methicillin-resistant Staphylococcus aureus (MRSA) strains, designing their antibacterial alternatives is necessary. Besides, the use of vancomycin is applied for specific detection of the bacteria. Silver-incorporated vancomycin-modified mesoporous silica nanoparticles (MSNs@Van@Ag NPs) were designed for detection and treatment of MRSA bacteria. Mesoporous silica nanoparticles (MSNs) were synthesized through the template method, modified with vancomycin, and finally incorporated with silver nanoparticles (Ag NPs). The MSNs@Van@Ag NPs with a homogenously spherical shape, average size of 50-100nm, surface area of 955.8m2/g, and thermal stability up to 200°C were successfully characterized. The amount of Ag incorporated into the MSNs@Van@Ag was calculated at 3.9ppm and the release amount of Ag was received at 2.92ppm (75%) after 100h. The in vitro antibacterial susceptibility test showed the MIC of 100μg mL-1 for MSNs@Van and 50μg mL-1 for MSNs@Van@Ag, showing in vitro enhanced effect of Ag and vancomycin in the bactericidal process. An in vivo acute pneumonia model was performed and biochemical assays and pathological studies confirmed the nanomedicine's short-term safety for in vivo application. Cytokine assay using ELISA showed that MSN@Van@Ag causes a reduction of pro-inflammatory cytokines and bacterial proliferation leading to alleviation of inflammatory response.

Exploring the Antimicrobial Potential of Hallachrome, a Defensive Anthraquinone from the Marine Worm Halla parthenopeia (Polychaeta).

Antimicrobial resistance is a critical global health issue, with rising resistance among bacteria and fungi. Marine organisms have emerged as promising, but underexplored, sources of new antimicrobial agents. Among them, marine polychaetes, such as Halla parthenopeia, which possess chemical defenses, could attract significant research interest. This study explores the antimicrobial properties of hallachrome, a unique anthraquinone found in the purple mucus of H. parthenopeia, against Gram-negative bacteria (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 9027), Gram-positive bacteria (Enterococcus faecalis ATCC 29212, Staphylococcus aureus ATCC 6538, Staphylococcus epidermidis ATCC 12228), and the most common human fungal pathogen Candida albicans ATCC 10231. Antibacterial susceptibility testing revealed that Gram-negative bacteria were not inhibited by hallachrome at concentrations ≤2 mM. However, Gram-positive bacteria showed significant growth inhibition at 0.12-0.25 mM, while C. albicans was inhibited at 0.06 mM. Time-kill studies demonstrated dose-dependent growth inhibition of susceptible strains by hallachrome, which exerted its effect by altering the membrane permeability of C. albicans, E. faecalis, and S. epidermidis after 6 h and S. aureus after 24 h. Additionally, hallachrome significantly reduced biofilm formation and mature biofilm in S. aureus, E. faecalis, and C. albicans. Additionally, it inhibited hyphal growth in C. albicans. These findings highlight hallachrome's potential as a novel antimicrobial agent, deserving further exploration for clinical experimentation.

Antibacterial Resistance and Extended-Spectrum Beta-Lactamase (ESBL) Phenotypes in Enterobacteriaceae Isolated from Fecal Samples of Humans and Animals in Selected Local Government Areas of Nasarawa State, Nigeria

It is quite alarming the increasing rate of antibacterial resistance all over the world considering the public health threat and the re-emergence of multi-drug resistant Enterobacteriaceae. The aim of this study is Antibacterial resistance and phenotypic detection of Extended Spectrum Beta-Lactamase (ESBL) producing Enterobacteriaceae isolated from human and animal fecal samples in selected local government areas of Nasarawa state, Nigeria was carried out in the study. Hundred (100) samples comprising human and animal (goats, cattle, and chicken) were collected and 55 samples were multidrug resistant. A commercial biochemical kit (Eneterosystem 18R) was used for the isolation and identification of Enterobacteriaceae. Kirby Bauer Disk Diffusion Method was used for antibacterial susceptibility testing of Enterobacteriaceae isolates. The Double Disc Synergy Test (DDST) method was also used for the phenotypic confirmation test of Extended Spectrum Beta Lactamase (ESBL). The occurrence of multidrug-resistant isolates shows that Escherichia coli (100.00%) which is the highest, Proteus mirabilis (14.54%), Klebsiella pneumoniae, and Salmonella enterica (10.90%), while the occurrence of Shigella flexneri (9.09%) was the lowest. The Enterobacteriaceae isolates were more resistant to Cefuroxime, Cefexime, Amoxicillin Clavulanate, and Imipenem/Cilastatin with percentage resistance ranges from 66.6% - 100%. The occurrence of ESBL producers shows that Escherichia coli (60.00%) and Proteus mirabilis (62.5%) were high while Shigella flexneri (20.0%) had a low occurrence of ESBL. The sale and in-discriminate use of antibiotics without a prescription is an important regulatory issue in the abuse of antibiotics for both humans and animals. The Beta-Lactam and gentamycin antibiotics were not effective against the Multi-Drug Resistant (MDR) isolates and most of the isolates were ESBL producers.

Cytotoxicity and antibacterial susceptibility assessment of a newly developed pectin–chitosan polyelectrolyte composite for dental implants

Biopolymers such as chitosan and pectin are currently attracting significant attention because of their unique properties, which are valuable in the food industry and pharmaceutical applications. These properties include non-toxicity, compatibility with biological systems, natural decomposition ability, and structural adaptability. The objective of this study was to assess the performance of two different ratios of pectin–chitosan polyelectrolyte composite (PCPC) after applying them as a coating to commercially pure titanium (CpTi) substrates using electrospraying. The PCPC was studied in ratios of 1:2 and 1:3, while the control group consisted of CpTi substrates without any coating. The pull-off adhesion strength, cytotoxicity, and antibacterial susceptibility tests were utilized to evaluate the PCPC coatings. In order to determine whether the composite coating was the result of physical blending or chemical bonding, the topographic surface parameters were studied using Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM). PCPC (1:3) had the highest average cell viability of 93.42, 89.88, and 86.85% after 24, 48, and 72 h, respectively, as determined by the cytotoxicity assay, when compared to the other groups. According to the Kirby–Bauer disk diffusion method for testing antibacterial susceptibility, PCPC (1:3) showed the highest average diameter of the zone of inhibition, measuring 14.88, 14.43, and 11.03 mm after 24, 48, and 72 h of incubation, respectively. This difference was highly significant compared to Group 3 at all three time periods. PCPC (1:3) exhibited a significantly higher mean pull-off adhesion strength (521.6 psi) compared to PCPC (1:2), which revealed 419.5 psi. PCPC (1:3) coated substrates exhibited better surface roughness parameters compared to other groups based on the findings of the AFM. The FTIR measurement indicated that both PCPC groups exhibited a purely physical blending in the composite coating. Based on the extent of these successful in vitro experiments, PCPC (1:3) demonstrates its potential as an effective coating layer. Therefore, the findings of this study pave the way for using newly developed PCPC after electrospraying coating on CpTi for dental implants.

Aerobic Bacteria and Their Antibiotic Resistance Profile in Neonatal Septicaemia: A cross Sectional Study in a Tertiary Care Hospital of Rajshahi, Bangladesh

Objective: Neonatal sepsis is an infection of the bloodstream in infants younger than 28 days old. It continues to be the major cause of morbidity and mortality among newborns, particularly in middle- and low-income nations. The objective of this study was to isolate and identify aerobic bacteria of neonatal sepsis by blood culture using FAN method followed by subculture and relevant biochemical tests. Methods: It was a cross sectional type of descriptive study where the sample size was 95 and data were collected purposively from the clinically suspected neonatal septicaemia cases from inpatient Pediatric department in Rajshahi Medical College Hospital, Rajshahi. Results: Most 34 (35.79%) of the cases were culture positive, whereas 61 (64%) were culture negative. 7 (21%) of the 34 positive cases were Gram-positive, while 27 (79%) were Gram-negative. S. aureus was found in 6 (17.65%) of the culture-positive isolates, followed by CoNS with 1 (02.94%), E. coli with 14 (41.17%), Klebsiella spp. with 6 (17.65%), P. aeruginosa with 6 (17.65%), and Acinetobacter with 1 (02.94%). Gram-positive bacteria were extremely susceptible to Vancomycin (90%), Gentamicin (90%), and Ciprofloxacin (80%) based on antibacterial susceptibility testing. Colistin (100%) and ampicillin (100%) exhibited the greatest resistance. Meropenem (90%), Amikacin (90%), and Colistin (89%) were the most effective antibiotics against Gram-negative bacteria, whereas Ceftazidime (60%) was the least effective. Vancomycin (100%) and ampicillin (100%) exhibited the highest degree of resistance. Conclusion: Both Gram-positive and Gram-negative aerobic bacteria were related with newborn septicaemia, and a significant proportion of them were resistant to multiple medicines. CME J 2024; 3(2); 4-11

Screening for Plasmid Mediated Antibiotic Resistance among Multi Drug Resistant Bacteria Isolated from Patients with Lower Respiratory Tract Infections Attending some Hospitals in Kano Metropolis

Study’s Novelty/Excerpt This study investigates the prevalence and plasmid-mediated resistance of multidrug-resistant (MDR) bacteria isolated from patients with lower respiratory tract infections (LRTIs), revealing significant findings pertinent to public health. The research demonstrates a high prevalence of MDR isolates (20%) and highlights the substantial role of plasmids, with 67.6% of MDR isolates containing plasmids, and 80% losing drug resistance post-plasmid curing. These results underscore the necessity for treatment options based on antibiotic susceptibility testing and continuous plasmid profiling to combat plasmid-mediated resistance effectively, marking a critical advancement in the management of LRTIs. Full Abstract Lower Respiratory tract infections (LRTIs) are among the serious infections in humans that have been worsening by the emergence of drug resistant bacteria and aggravated by plasmids transfer. The study aimed to screen Multidrug-resistant (MDR) bacteria isolated from patients with LRTIs for the presence of Plasmid. Sputum samples (400) were collected from patients with LRTIs and processed using standard microbiological procedures to isolate lower respiratory tract bacteria. The identified isolates were subjected to antibacterial susceptibility testing using the disc diffusion method. Multidrug resistant isolates were further subjected to plasmid curing using Acridine orange and the cured isolates were tested for loss of drug resistance. Among the 400 samples, 185 (46.2 %) harbored significant bacterial growth, with 83 (44.9%) Gram-positive and 102 (55.1%) Gram-negative bacteria. Bacteria isolated include Escherichia coli (29), Klebsiella pneumonia (46), Moraxella catarrhalis (13), Pseudomonas aerugonosa (14), Staphylococcus aureus(24) and Streptococcus pneumoniae (59). A higher infection rate was recorded in males (46.99%) and patients aged 41-50 (52.59%). The highest resistance was exhibited by Klebsiella pneumoniae (93%) against cefuroxime, followed by Streptococcus pneumoniae against oxacillin (75%). Of the 185 isolates, 37 (20%) were MDR, out of which 25 (67.6%) isolates had Plasmids. Following curing, 20 (80%) of the isolates were cured, and only 5 (20%) retained their plasmids. Most importantly, Escherichia coli and Klebsiella pneumonia were found to be sensitive to levofloxacin, gentamicin, and imipenem but retained their resistance to Cefuroxime, while Streptococcus pneumoniae was found to be sensitive to levofloxacin only with the highest resistance to oxacillin, doxycycline, and erythromycin. The study establishes a high prevalence of MDR isolates among LRTIs, with some exhibiting plasmid-mediated resistance, and therefore recommends treatment options to be solely based on antibiotic susceptibility testing and continuous plasmid profiling to detect plasmid-mediated resistance to enable appropriate drug administration.

Synthesis, characterization and antimicrobial activities of some quinoxaline-, naphthalene- and xylene-based macrocyclic compounds

Seven novel macrocyclic drug candidates having quinoxaline, naphthalene and xylene subunits were synthesized in order to investigate their antimicrobial suitability in combating drug resistance. The macrocycles and their intermediates were characterize using 1H NMR, 13C NMR, FT-IR and HRMS spectrometry. The intermediates were synthesized by reacting various derivatives of salicylaldehyde with 1,3-bis(aminomethyl)benzene (route I) or 2,4-bis(chloromethyl)-1,3,5-trimethylbenzene (route II), the intermediates were cyclized via [1 + 1] high dilution cyclization reaction into the seven macrocycles in approximately equal yield for both route I and II. Invitro antibacterial and antifungal susceptibility tests were carried out for each of the macrocycles on Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli, Pseudomonas aeruginosa and Candida albicans. The macrocycles showed good antimicrobial potency when compare with standard antibiotics (Gentamycin, Tetracyclin, Fluconazole and Amphoteracin B).

Chemical analysis and antibacterial susceptibility of some brands of amoxicillin suspension marketed in Sagamu, Ogun, Nigeria

AbstractPoor quality medicines present a serious public health concern and have a significant impact on national clinical and economic burden. This study was carried out for comparative quality assessment of different brands of amoxicillin suspension in Sagamu community in Nigeria to determine their suitability for the therapeutic purpose. Ten brands of 125 mg/5 mL amoxicillin suspension, marketed in Sagamu community pharmacies were procured and subjected to chemical analysis using the high‐performance liquid chromatography method according to the official procedures in United State Pharmacopoeia (USP) and the microbiological analysis on different clinical isolates which include Pseudomonas aeruginosa, Escherichia coli, Streptococcus pyogene, and Staphylococcus aureus using agar disc diffusion antimicrobial susceptibility testing. The results of the high‐performance liquid chromatography revealed the percentage content of the brands A, B, C, D, E, F, G, H, I, and J to be 97.39%, 57.078%, 91.565%, 98.137%, 61.694%, 103.337%, 91.454%, 106.683%, 75.109%, and 96.895% w/v, respectively. The result of the high‐performance liquid chromatography reveals the brands (A, C, D, F, G, H, and J) had a percentage within the required range and were deemed unsuitable for therapeutic use. In the microbiological analysis, all the brands passed the antibacterial susceptibility testing except for brand (B, E, and I) which were not susceptible to S. aureus due to their zone of inhibition being less than 15 mm. Overall, this study emphasizes the importance of quality assurance in the pharmaceutical industry to ensure that only high‐quality drugs are made available to the population for optimal therapeutic benefit.

Design, synthesis, and bioactivity evaluation of clindamycin derivatives against multidrug-resistant bacterial strains.

Our research aims to reduce the bacterial resistance of clindamycin against Gram-positive bacteria and expand its range of bacterial susceptibility. First, we optimized the structure of clindamycin based on its structure-activity relationship. Second, we employed the fractional inhibitory concentration method to detect drugs suitable for combination with clindamycin derivatives. We then used a linker to connect the clindamycin derivatives with the identified combined therapy drugs. Finally, we tested antibacterial susceptibility testing and conducted in vitro bacterial inhibition activity assays to determine the compounds. with the highest efficacy. The results of our study show that we synthesized clindamycin propionate derivatives and clindamycin homo/heterodimer derivatives, which exhibited superior antibacterial activity compared to clindamycin and other antibiotics against both bacteria and fungi. In vitro bacteriostatic activity testing against four types of Gram-negative bacteria and one type of fungi revealed that all synthesized compounds had bacteriostatic effects at least 1000 times better than clindamycin and sulfonamides. The minimum inhibitory concentration (MIC) values for these compounds ranged from 0.25 to 0.0325 mM. Significantly, compound 5a demonstrated the most potent inhibitory activity against three distinct bacterial strains, displaying MIC values spanning from 0.0625 to 0.0325 mM. Furthermore, our calculations indicate that compound 5a is safe for cellular use. In conclusion, the synthesized compounds hold great promise in addressing bacterial antibiotic resistance.

Correlation of CD4+ count and viral load with urinary tract infection and antimicrobial resistance pattern of bacterial uropathogens among HIV patients in Wolaita Sodo, South Ethiopia.

The permanence of HIV patients in healthcare provision centers exposes their weak immunity to various nosocomial microorganisms that migrate into and out of the hospital environment. The incidence of bacterial infections, including urinary tract infection, was inversely correlated with CD4+ T cells. Urinary tract infection (UTI) is one of the clinical problems among HIV patients. There was scarcity of published data on the relationship between viral load, CD4+ level, and UTI. This study aimed to assess the relationship between viral load and CD4 with bacterial UTI among HIV patients. The cross-sectional study was conducted in the Wolaita Sodo Town Health Center ART clinic. The socio-demographic data were collected using a pre-designed questionnaire. Patients' charts were reviewed to collect the current CD4 and viral load. Urine specimens were inoculated on blood agar, cysteine lactose electrolyte deficient (CLED) agar, and MacConkey agar, and bacterial species were finally identified using various biochemical methods. Antimicrobial sensitivity testing was conducted using standard microbiological tests. Bivariate and multivariate analyses were employed to describe the association between pairs of variables and to examine the relationship between independent variables and dependent variables. In this study, the overall prevalence of urinary tract infection (UTI) was 13.7%. Escherichia coli, Staphylococcus aureus, Pseudomonas aeroginosa, Staphylococcus saprophyticus, Proteus mirabilis, and Klebsiella pneumoniae were bacterial uropathogens detected in this study. E.coli (45.7%) was the predominant isolate followed by S. aureus (14.3%). Positive correlation between CD4+ count and urinary tract infection was detected and found statistically significant (r = 0.288 p > 0.01), whereas the viral load and urinary tract infection negatively correlated and showed statistically significant association (p < 0.01). The resistance rate of E.coli was 94%, 75%, and 69% to ciprofloxacin, norfloxacin, and cefepime, respectively. This study revealed that E.coli exhibited 94% and 75% resistance to amoxicillin-clavulanic acid and tetracycline, respectively. K. pneumoniae demonstrated complete resistance (100%) to amoxicillin-clavulanic acid, tetracycline, and trimethoprim-sulfamethoxazole, while showing 100% susceptibility to ciprofloxacin and nitrofurantoin. In the present study, the magnitude of the multi-drug resistance (MDR) was found to be 80%. CD4+ count, combination of antiretroviral therapy (ART) drugs, and a history of hospitalization were risk factors for urinary tract infection. In the current study, urinary tract infection emerged as a significant health concern among people living with HIV following their ART. The occurrence of urinary tract infection among HIV patients could be influenced by multifactorial factors that require further study. The CD4+ count was positively correlated with the prevalence of UTI, whereas the viral load was negatively correlated. The CD4+ count, combination of ART, and history of hospitalization were independent risk factors for UTI. The prevalence of MDR bacterial pathogens were notably high. Therefore, the treatment of UTI in HIV patients should be prescribed based on antibacterial susceptibility testing results.

The Phytochemical Composition and Antibacterial Effects of Allium sativum Clove Extracts on Some Enteric Bacterial Pathogens

In this study, the phytochemicals present in the cloves of Allium sativum were determined, and their antibacterial activities against some enteric bacterial pathogens were assessed. The phytochemical constituents were determined after the extraction process was completed using water and ethanol as the solvents. Furthermore, the aqueous and ethanolic extracts of A. sativum were tested against Escherichia coli, Salmonella typhi and Shigella dysenteriae isolated from faeces of gastroenteritis patients. The agar diffusion technique (punch method) was used for this. Additionally, the extracts' minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined. The mean values of the zones of inhibition obtained were statistically analyzed using ANOVA. The least significant difference was determined according to the LSD test at P&lt;0.05. The results of the phytochemical analysis revealed the presence of saponin, alkaloids, flavonoids, and tannins. Furthermore, the antibacterial susceptibility test showed that the aqueous and ethanolic extracts possess antibacterial properties against all the test organisms. The ethanolic extract at the concentration of 500mg/ml had zones of inhibition of 29.00b against E. coli, 24.00b against S. dysenteriae and the lowest 20.00b against S. typhi. On the other hand, at that same concentration, the aqueous extract had zones of inhibition of 20.00b against E. coli and 18.00b against S. dysenteriae and S. typhi. This study suggests that A. sativum extracts possess antibacterial properties. Furthermore, since the ethanolic extract was more effective than the aqueous extract, it could be that the antibacterial potency of A. sativum is solvent-dependent. In conclusion, the findings from this study suggest that further purification of the constituents of the plant might lead to the development of novel antibiotics.

Clinical characteristics and risk factors for mortality in Candida auris infections

AbstractBackgroundCandida auris infections pose a threat to public health, necessitating increased awareness in China. This study aimed to analyze the strains of C. auris, assess the infection status, and investigate clinical characteristics and risk factors for mortality.MethodsA retrospective analysis was conducted on 18 patients with Candida auris infection. We focused on evaluating basic characteristics, strain sources, and antibacterial susceptibility test results. Statistical methods were used to determine clinical features and identify risk factors for death.ResultsThe strain type, composition ratio, and specimen source of C. auris were not associated with mortality. Neither the infection index nor the length of hospitalization showed an association with the prognosis. However, significant risk factors for mortality included cerebral infarction, cardiac disease, renal dysfunction, hypoproteinemia, and anemia (all p &lt; 0.05).ConclusionsCerebral infarction, cardiac disease, renal dysfunction, hypoproteinemia, and anemia are significant risk factors for death in C. auris infections. These findings indicate the importance of recognizing and addressing these factors in the clinical management of C. auris infection.

Cobalt, Copper and Magnesium Doped Nickel Zinc Nanoferrites by Solution-Combustion Method: Structural, Antibacterial and Antifungal Properties

The nickel zinc nanoferrites with configurationNi0.45Zn0.55–xMxFe2O4were achieved where x = 0.0, 0.1, 0.2 and 0.3 and M = Cobalt, Copper, Magnesiumusing solution-combustion method by availing sucrose as a fuel. The procured nanoferrites were investigated forstructural properties using TEM, antibacterial and antifungal propertiesby Kirby-Bauer Disk Diffusion Susceptibility Test also calledas Agar diffusion method. The synthesized nanoferrites were tested for their antibacterial activities against Gram negative (Escherichiacoli) and Gram positive (Bacillus cerus) bacterial strains. Also, investigation was evaluated for their antifungal activity against Aspergillus niger. Against Bacillus cerus, sample Ni0.45 Zn0.45Cu0.1Fe2O4 showed maximum antibacterial activity. The maximum antifungal activity was observed for Ni0.45 Zn0.35Co0.2Fe2O4.

Antibiotic resistance and virulence profiles of Proteus mirabilis isolated from broiler chickens at abattoir in South Africa.

Proteus mirabilis has been identified as an important zoonotic pathogen, causing several illnesses such as diarrhoea, keratitis and urinary tract infections. This study assessed the prevalence of P. mirabilis in broiler chickens, its antibiotic resistance (AR) patterns, ESBL-producing P. mirabilis and the presence of virulence genes. A total of 26 isolates were confirmed as P. mirabilis from 480 pooled broiler chicken faecal samples by polymerase chain reaction (PCR). The disk diffusion method was used to evaluate the antibacterial susceptibility test, while nine virulence genes and 26 AR genes were also screened by PCR. All 26 P. mirabilis isolates harboured the ireA (siderophore receptors), ptA, and zapA (proteases), ucaA, pmfA, atfA, and mrpA (fimbriae), hlyA and hpmA (haemolysins) virulence genes. The P. mirabilis isolates were resistant to ciprofloxacin (62%) and levofloxacin (54%), while 8 (30.7%) of the isolates were classified as multidrug resistant (MDR). PCR analysis identified the blaCTX-M gene (62%), blaTEM (58%) and blaCTX-M-2 (38%). Further screening for AMR genes identified mcr-1, cat1, cat2, qnrA, qnrD and mecA, 12%, 19%, 12%, 54%, 27% and 8%, respectively for P. mirabilis isolates. The prevalence of the integron integrase intI1 and intI2 genes was 43% and 4%, respectively. The rise of ciprofloxacin and levofloxacin resistance, as well as MDR strains, is a public health threat that points to a challenge in the treatment of infections caused by these zoonotic bacteria. Furthermore, because ESBL-producing P. mirabilis has the potential to spread to humans, the presence of blaCTX -M -producing P. mirabilis in broilers should be kept under control. This is the first study undertaken to isolate P. mirabilis from chicken faecal samples and investigate its antibiotic resistance status as well as virulence profiles in South Africa.