Bacterial Susceptibility Research Articles

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.

Nanotechnology-driven strategies to enhance the treatment of drug-resistant bacterial infections.

The misuse of antibiotics has led to increased bacterial resistance, posing a global public health crisis and seriously endangering lives. Currently, antibiotic therapy remains the most common approach for treating bacterial infections, but its effectiveness against multidrug-resistant bacteria is diminishing due to the slow development of new antibiotics and the increase of bacterial drug resistance. Consequently, developing new a\ntimicrobial strategies and improving antibiotic efficacy to combat bacterial infection has become an urgent priority. The emergence of nanotechnology has revolutionized the traditional antibiotic treatment, presenting new opportunities for refractory bacterial infection. Here we comprehensively review the research progress in nanotechnology-based antimicrobial drug delivery and highlight diverse platforms designed to target different bacterial resistance mechanisms. We also outline the use of nanotechnology in combining antibiotic therapy with other therapeutic modalities to enhance the therapeutic effectiveness of drug-resistant bacterial infections. These innovative therapeutic strategies have the potential to enhance bacterial susceptibility and overcome bacterial resistance. Finally, the challenges and prospects for the application of nanomaterial-based antimicrobial strategies in combating bacterial resistance are discussed. This article is categorized under: Biology-Inspired Nanomaterials > Nucleic Acid-Based Structures Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease.

MICROBIOLOGICAL ASSESSMENT OF INDOOR AIR QUALITY OF STUDENT HOSTELS AND CANTEENS IN A NIGERIAN UNIVERSITY CAMPUS: RISKS ON STUDENTS’ HEALTH

Microbial air contaminants affect the quality of air we breathe and these microbial air contaminants can settle on body parts, clothes, food etc. which poses a serious threat to human health. Therefore, the level of bacterial contamination in various in-door air of the students’ hostels and canteens of Kaduna State University (KASU) and their antibiotics susceptibility patterns was studied. A total of 44 samples were collected from the rooms (18), toilets (18) of the students hostels and canteen (8) of KASU; using the settle plate method. Gram staining and standard biochemical methods were used to identify the bacterial isolates and antibiotic susceptibility testing was determined by disc diffusion method. The bacteria load was between 1.2 x 103 to 6.7 x 103 cfu/ml3. A total of 30 bacteria isolates were identified, Staphylococcus aureus had the highest (9, 30%) occurrence, followed by Streptococcus spp (6, 20%), Bacillus subtilis and Clostridium spp had similar (4, 13.2%) occurrence, The antibiotic susceptibility testing carried out revealed that the Gram negative and Gram positive bacteria isolates were more susceptible to vancomycin (75%, 43.5%), tetracycline (75%, 47.8%) and gentamicin (50%, 43.5%) while high resistance was observed with chloramphenicol (100%, 73.9%), ceftriaxone (100%, 100%), cefoxitin (100%, 73.9%), amoxicillin/clavulanic acid (100%, 87%), and trimethoprim/sulphamethoxazole (100%, 78%). All the indoor samples were contaminated with pathogenic bacteria and there was high level of multidrug resistance. This is very dangerous to the students’ health because it can be a source of transmission infections and antibiotic resistant bacterial strains.

Bacterial aetiology and antimicrobial susceptibility of osteoarticular infections at a tertiary-level paediatric unit in South Africa

Bacterial aetiology and antimicrobial susceptibility of osteoarticular infections at a tertiary-level paediatric unit in South Africa

Endophthalmitis after cataract surgery and effect of different intracameral antibiotic regimes in Sweden 2011-2017: national registry study.

To study the incidence, predictive factors, etiology, and visual consequences of postoperative endophthalmitis (PE) in relation to 3 intracameral (IC) antibiotic regimes. Swedish National Cataract Register entries from 2011 through 2017. Observational retrospective study. PE incidence, influencing factors, bacteriology, and visual outcome were analyzed regarding the 3 major prophylactic IC protocols. The overall incidence of PE was 0.023% or 177 cases in 764 513 cataract procedures. Analyzed per IC regime, the rates of PE were 0.024% (126 cases in 514 916 surgeries) for cefuroxime, 0.020% (25 cases in 122 340 surgeries) for moxifloxacin, and 0.017% (20 cases in 121 045 surgeries) for combined cefuroxime-ampicillin. Incidences were not statistically significantly different from one another. Gram-positive bacteria caused 89.0% of culture positive cases. Enterococci as pathogens were significantly more frequent with IC cefuroxime than with moxifloxacin, P = .006, or cefuroxime-ampicillin, P < .001, while streptococci other than enterococci were more common with moxifloxacin than with cefuroxime, P < .001. Bacterial susceptibility to the given antibiotics was demonstrated in 21.3% of PE cases treated with cefuroxime, which was statistically significantly lower than proportions found with cefuroxime-ampicillin, 60.0%, P = .015, or with moxifloxacin, 88.2%, P < .001. Visual outcome worse than 20/200 was similar in the groups ranging from 42.0% to 53.7%. No statistically significant differences in PE incidence or visual outcome results between treatment groups were demonstrated. However, differences in etiology and bacterial sensitivity were found between the prophylactic IC treatments.

Detection of multidrug-resistant organisms of concern including Stenotrophomonas maltophilia and Burkholderia cepacia at a referral hospital in Kenya.

Regular monitoring of bacterial susceptibility to antibiotics in clinical settings is key for ascertaining the current trends as well as re-establish empirical therapy. This study aimed to determine bacterial contaminants and their antimicrobial susceptibility patterns from medical equipment, inanimate surfaces and clinical samples obtained from Thika Level V Hospital (TLVH), Thika, in Central Kenya. Three hundred and five samples were collected between the period of March 2021 to November 2021 and comprised urine, pus swabs, catheter swabs, stool, and environmental samples. Bacterial identification and antimicrobial susceptibility were performed using VITEK 2 and disc diffusion respectively. We observed that Coagulase-negative Staphylococci (28 /160, 17.5%) were the most commonly isolated species from clinical samples followed by E. coli (22 /160 13.8%) and S. aureus (22/160, 13.8%). The bed rails were the mostly contaminated surface with S. aureus accounting for 14.2% (6/42). Among the clinical samples, pus swabs yielded the highest number of pathogens was pus (92/160). Trauma patients had the highest proportion of isolates (67/160, 41.8%). High level of antimicrobial resistance to key antimicrobials, particularly among Enterobacterales was observed. Extended Spectrum Beta Lactamase (ESBL) phenotype was noted in 65.9% (29/44) of enteric isolates. While further ESBL genetic confirmatory studies are needed, this study highlights the urgent need for actions that mitigate the spread of antibiotic-resistant bacteria.

Bacterial etiology and antimicrobial resistance pattern of pediatric bloodstream infections: a 5-year experience in an Iranian referral hospital

BackgroundBloodstream infections (BSI) are the major cause of morbidity and mortality in children in developing countries. The purpose of the current study was to establish the antimicrobial susceptibility pattern of bacterial isolates from bloodstream infections at Children’s Medical Center Hospital (CMC), Tehran, Iran.MethodsWe retrospectively recorded all positive blood cultures and antimicrobial susceptibility of all bloodstream isolates among children admitted to CMC, during 5 years. Specimen culture, bacterial identification, and antimicrobial susceptibility testing were performed according to standard laboratory methods.ResultsFrom 3,179 pathogens isolated from the blood cultures 2,824 bacteria were cultured, with 1,312 cases being identified as Gram-positive bacteria (46%) and 1,512 cases as Gram-negative bacteria (54%). The most common Gram-negative bacteria isolated were as follows: Pseudomonas spp. (n = 266, 17.6%), Klebsiella pneumoniae (n = 242, 16%), Stenotrophomonas maltophilia (n = 204, 13.5%), Enterobacter spp. (n = 164, 10.8%), Escherichia coli (n = 159, 10.5%), Pseudomonas aeruginosa (n = 126, 8.3%), Serratia marcescens (n = 121, 8%), and Acinetobacter baumannii (n = 73, 4.8%). The most common Gram-positive bacteria isolated were coagulase-negative staphylococci (CONS) (n = 697, 53%), Streptococcus spp. (n = 237, 18%), Staphylococcus aureus (n = 202, 15%) and Enterococcus spp. (n = 167, 12.7%). 34% of bacterial strains were isolated from ICUs. The rates of methicillin resistance in S. aureus and CONS were 34% and 91%, respectively. E. coli isolates showed high resistance to cefotaxime (84%). All isolates of K. pneumoniae were susceptible to colistin and 56% were susceptible to imipenem. P. aeruginosa isolates showed high susceptibility to all antibiotics.ConclusionsOur findings emphasize the need of clinicians having access to up-to-date bacterial susceptibility data for routinely prescribed drugs. Continuous monitoring of changes in bacterial resistance will aid in the establishment of national priorities for local intervention initiatives in Iran. The increased risk of BSI caused by antibiotic-resistant organisms, emphasizes the significance of implementing appropriate antibiotic prescribing regulations and developing innovative vaccination techniques in Iran.

Nanoparticles Partially Restore Bacterial Susceptibility to Antibiotics.

The growing resistance of bacteria to antibiotics is one of the main public health problems nowadays. The influence of silver nanoparticle (AgNP) pretreatment of 220 cows with mastitis on the susceptibility of Staphylococcus epidermidis bacteria to 31 antibiotics was studied. The obtained results were compared with the previous results for Escherichia coli, Streptococcus dysgalactiae, and Staphylococcus aureus. For all four bacteria, an increase in susceptibility (9.5-21.2%) to 31 antibiotics after cow treatment with AgNPs was revealed, while after first-line antibiotic drug treatment as expected, the susceptibility decreased (11.3-27.3%). These effects were explained by (1) the increase in the contribution of isolates with efflux effect after antibiotic treatments and its decrease after AgNP treatment and (2) the changes in bacteria adhesion and anti-lysozyme activity after these treatments. The effect of the increasing antibacterial activity of antibiotics after AgNP treatment was the most pronounced in the case of E. coli and was minimal in the case of S. epidermidis. With AgNP treatment, the time of recovery decreased by 26.8-48.4% compared to the time of recovery after treatment with the first-line antibiotic drugs. The AgNP treatment allows for achieving the partial restoration of the activity of antibiotics.

Isolation of aerobic bacteria from abscesses and wounds in rabbits and antibiotic susceptibility testing of Staphylococcus spp. and Pseudomonas spp. isolates

BackgroundWound infections and abscesses in rabbits are a common problem in veterinary practice and their treatment can be challenging. Bacterial culture and antimicrobial susceptibility testing are important tools in these cases. While some studies are available on bacteria associated with wound infections and abscesses in rabbits, the numbers of animals included is generally limited. Monitoring of antibiotic resistance in clinical practice is also an important part of good antibiotic stewardship. Multiple antibiotic resistances are frequently encountered in Staphylococcus and Pseudomonas spp., two groups of bacteria commonly associated with abscesses in rabbits. MethodsThis retrospective study evaluated the results of aerobic bacterial cultures and antibiotic susceptibility tests in swabs from abscesses (A) (n=541) and from skin and wounds (SW) (n=308) submitted to a commercial diagnostic laboratory. Samples submitted between January 2017 and October 2020 were included in the study. Antimicrobial susceptibility testing for Staphylococcus and Pseudomonas spp. was evaluated and compared. ResultsIn A, 465 bacterial isolates including 35 different species were isolated while 394 bacterial isolates, including 35 different species, were found in SW. The most frequently isolated bacteria were Staphylococcus spp. (A = 21.7%, SW = 36.5%) followed by Pasteurella spp. in A (13.3%) and aerobic spore-forming bacteria in SW (11.2%). Pseudomonas spp. was the third most commonly isolated genus in both sample types (A = 11.6%, SW = 8.9%). Pseudomonas aeruginosa isolated from A were more often resistant to the tested antibiotics than other Pseudomonas species. These results support the need for bacterial culture and antibiotic susceptibility testing in small mammal practice.

The Distribution of Carbapenem-Resistant Acinetobacter Species and High Prevalence of CC92 OXA-23-Producing Acinetobacter Baumannii in Community Hospitals in South Korea.

Clinical isolates of Acinetobacter species in South Korea are continuously exhibiting high rates of antimicrobial resistance to carbapenems, indicating that there are public health concerns among both healthcare-associated infections and community-associated infections. The aim of this study was to describe the prevalence and characteristics of carbapenem-resistant Acinetobacter isolates originating from community hospitals. A total of 817 non-duplicated Acinetobacter species were isolated from December 2022 to July 2023 at long-term care facilities and general hospitals in 16 regions geographically distributed throughout South Korea. Bacterial identification and antimicrobial susceptibility testing were performed using the VITEK-2 system. The bacteria were identified as Acinetobacter baumannii by blaOXA-51 PCR and as non-baumannii Acinetobacter species by rpoB sequence analysis. The carbapenem resistance genes (OXA-23, OXA-48, OXA-58, IMP, VIM, NDM, GES, and KPC) were identified via PCR and sequencing. The genetic relatedness of carbapenem-resistant A. baumannii (CRAB) isolates was assessed by multilocus sequence typing. A total of 659 A. baumannii and 158 non-baumannii Acinetobacter isolates, comprising 19 different species, were identified in all 16 regions. The carbapenem resistance rate was 87.4% (n=576) for the A. baumannii isolates, and all the strains produced blaOXA-23. For non-baumannii Acinetobacter, the rate of carbapenem resistance was 8.9% (n=14); this resistance was primarily caused by blaOXA-23 (n=9), followed by blaNDM-1 (n=3) and blaVIM-2 (n=2). Of the 576 CRAB isolates, clonal complex 92 (CC92) was the predominant genotypes, followed by sequence type 229 (ST229), ST373, ST397, ST447, and ST620. Our results showed the distribution of Acinetobacter species and showed that CC92 CRAB clinical isolates with widespread production of blaOXA-23 were predominant in community hospitals. Our findings suggest that there is a need for urgent and effective methods to reduce carbapenem resistance in A. baumannii in South Korea.

Antibiotic Susceptibility Profile in Urinary Tract Infection Patients at Tarakan Regional Hospital

Background: Urinary tract infections (UTIs) are common in the community and hospital. In Indonesia, the incidence of UTI reaches 180,000 new cases per year. The most common pathogenic bacteria causing UTIs are dominated by Escherichia coli. Early empirical treatment of UTI cases can reduce morbidity. Knowing the pathogenic bacteria involved in urinary tract infections and their antimicrobial susceptibility patterns is necessary to provide appropriate empirical therapy. Purposes: Describe bacterial patterns and susceptibility profiles in urinary tract infection patients. Methods: A retrospective UTI dataset between 2019-2021whom admitted to Tarakan Regional General Hospital with a diagnosis of UTI. Resistance marker data for ESBL were obtained from the results of identification and resistance using the BD PhoenixTM Automated Microbiology System (Becton Dickinson, USA). The data was analyzed descriptively. Results: As many as 40 isolates were analyzed. Consist of E.coli (37.5%), Enterococcus faecium (20%) and Klebsiella pneumoniae (17.5%). The ESBL-producing E.coli bacteria rate reached 60%, while ESBL-producing K. pneumoniae reached 100%. Conclusion: E. coli was the most common pathogen, with the highest antibiotic sensitivity being imipenem, meropenem, and amikacin.

Modern developments in burn wound dressing

Purpose Intense interest has been shown in creating new and effective biocide agents as a result of changes in bacterial isolates, bacterial susceptibility to antibiotics, an increase in patients with burns and wounds and the difficulty of treating infections and antimicrobial resistance. Woven, nonwoven and knitted materials are used to make dressings; however, nonwoven dressings are becoming more popular because of their softness and high absorption capacity. Additionally, textiles have excellent geometrical, physical and mechanical features including three-dimensional structure availability, air, vapor and liquid permeability, strength, extensibility, flexibility and diversity of fiber length, fineness and cross-sectional shapes. It is necessary to treat every burn according to international protocol and along with it has to focus on particular problems of patients and the best possible results. Design/methodology/approach The objective of this paper is to conduct a thorough examination of research pertaining to the utilization of textiles, as well as alternative materials and innovative techniques, in the context of burn wound dressings. Through a critical analysis of the findings, this study intends to provide valuable insights that can inform and guide future research endeavors in this field. Findings In the past years, there have been several dressings such as xeroform petrolatum gauze, silver-impregnated dressings, biological dressings, hydrocolloid dressings, polyurethane film dressings, silicon-coated nylon dressings, dressings for biosynthetic skin substitutes, hydrogel dressings, newly developed dressings, scaffold bandages, Sorbalgon wound dressing, negative pressure therapy, enzymatic debridement and high-pressure water irrigation developed for the fast healing of burn wounds. Originality/value This research conducts a thorough analysis of the role of textiles in modern burn wound dressings.

Best Practice of Peritoneal Dialysis-Associated Gram-Negative Peritonitis in Children: Insights From the International Pediatric Peritoneal Dialysis Network Registry

Gram-negative peritonitis (GNP) is associated with significant morbidity in children receiving long-term peritoneal dialysis (PD) and current treatment recommendations are based on limited data. Analysis of 379 GNP episodes in 308 children (median age 6.9 years, interquartile range [IQR]: 3.0-13.6) from 45 centers in 28 countries reported to the International Pediatric Peritoneal Dialysis Network registry between 2011 and2023. Overall, 74% of episodes responded well to empiric therapy and full functional recovery (FFR) was achieved in 82% of cases. Invitro bacterial susceptibility to empiric antibiotics and lack of severe abdominal pain at onset were associated with a good initial response. Risk factors for failure to achieve FFR included severe abdominal pain at onset and at 60 to 72 hours from treatment initiation (odds ratio [OR]: 3.81, 95% confidence interval [CI]: 2.01-7.2 and OR: 3.94, 95% CI: 1.06-14.67, respectively), Pseudomonas spp. etiology (OR: 1.73, 95% CI: 1.71-4.21]) and invitro bacterial resistance to empiric antibiotics (OR: 2.40, 95% CI: 1.21-4.79); the risk was lower with the use of monotherapy as definitive treatment (OR: 0.40, 95% CI: 0.21-0.77). Multivariate analysis showed no benefit of dual antibiotic therapy for treatment of Pseudomonas peritonitis after adjustment for age, presenting symptomatology, 60 to 72-hour treatment response, and treatment duration. Monotherapy with cefazolin in susceptible Enterobacterales peritonitis resulted in a similar FFR rate (91% vs. 93%) as treatment with ceftazidime or cefepime monotherapy. Detailed microbiological assessment, consisting of patient-specific and center-specific antimicrobial susceptibility data, should guide empiric treatment. Treatment "deescalation" with the use of monotherapy and narrow spectrum antibiotics according to susceptibility data is not associated with inferior outcomes and should be advocated in the context of emerging bacterial resistance.

Phage resistance in Klebsiella pneumoniae and bidirectional effects impacting antibiotic susceptibility

ObjectivesBacteriophage (phage) therapy is a promising anti-infective option to combat antimicrobial resistance. However, the clinical utilization of phage therapy has been severely compromised by the potential emergence of phage resistance. Although certain phage resistance mechanisms can restore bacterial susceptibility to certain antibiotics, a lack of knowledge of phage resistance mechanisms hinders optimal use of phages and their combination with antibiotics. MethodsGenome-wide transposon screening was performed with a mutant library of Klebsiella pneumoniae MKP103 to identify phage pKMKP103_1-resistant mutants. Phage-resistant phenotypes were evaluated by time-kill kinetics and efficiency of plating assays. Phage resistance mechanisms were investigated with adsorption, one-step growth, and mutation frequency assays. Antibiotic susceptibility was determined with broth microdilution and population analysis profiles. ResultsWe observed a repertoire of phage resistance mechanisms in K pneumoniae, such as disruption of phage binding (fhuA::Tn and tonB::Tn), extension of the phage latent period (mnmE::Tn and rpoN::Tn), and increased mutation frequency (mutS::Tn and mutL::Tn). Notably, in contrast to the prevailing view that phage resistance re-sensitizes antibiotic-resistant bacteria, we observed a bidirectional steering effect on bacterial antibiotic susceptibility. Specifically, rpoN::Tn increased susceptibility to colistin while mutS::Tn and mutL::Tn increased resistance to rifampicin and colistin. DiscussionOur findings demonstrate that K pneumoniae employs multiple strategies to overcome phage infection, which may result in enhanced or reduced antibiotic susceptibility. Mechanism-guided phage steering should be incorporated into phage therapy to better inform clinical decisions on phage-antibiotic combinations.

Role of ArcA in the regulation of antibiotic sensitivity in avian pathogenic Escherichia coli

Avian pathogenic Escherichia coli (APEC) is one of the common extraintestinal infectious disease pathogens in chickens, geese, and other birds, inducing serious impediments to the development of the poultry industry. Hence, investigating how bacteria regulate themselves amidst different challenging conditions is immense essential in prevention and treatment for bacterial pathogen infections. The ArcA regulatory factor has been reported to regulate oxygen availability in strains, but its role in regulation of antibiotics resistance in APEC is unclear. This study delved into understanding how ArcA regulates antibiotic resistance in APEC. An E. coli APEC40 arcA knockout strain was constructed, and the regulatory mechanism of arcA on APEC antibiotic susceptibility was identified by drug sensitivity test, colony counting assay, real-time quantitative PCR, β-galactosidase assays and electrophoretic mobility shift assay (EMSA). The results showed that ArcA directly binds to the promoter region of the outer membrane protein OmpC/OmpW and regulates bacterial susceptibility to kanamycin and penicillin G. At the same time, the double knockout of ompW and ompW/arcA resulted in an increase in resistance to kanamycin compared to the deletion of the arcA gene. This outcome provided experimental proof suggesting that the outer membrane protein OmpW could serve as a crucial pathway for the ingress of kanamycin into cells. These results confirmed the important regulatory role of ArcA transcription factors under APEC antibiotic stress.

Investigation of Uropathological Bacterial Profile and Antibiotic Susceptibility Patterns Among Pregnant Women in Rawalpindi and Islamabad: A Comprehensive Analysis

Background: Urinary tract infections (UTIs) represent a significant health concern for pregnant women, potentially leading to adverse outcomes for both mother and child. The anatomical and physiological changes during pregnancy increase the risk of UTIs, making the study of their bacteriological profile and antibiotic susceptibility patterns especially pertinent. Objective: This study aimed to assess the bacteriological profile and antibiotic susceptibility patterns of UTIs among pregnant women in Rawalpindi and Islamabad, to identify the most prevalent pathogens and their resistance to commonly used antibiotics. Methods: A cross-sectional study was conducted on 165 early morning mid-stream urine samples collected from pregnant women attending the Railway General Hospital, Rawalpindi, over four months. Samples were analyzed for UTI-causing organisms using Cysteine Lactose Electrolyte Deficient (CLED) medium, MacConkey agar, and blood agar plates. Gram staining and biochemical tests were utilized for bacterial identification, while the Kirby-Bauer disk diffusion method determined antibiotic susceptibility. Statistical analysis was performed using SPSS version 25. Results: The study population predominantly consisted of residents from Rawalpindi (94.5%). The highest incidence of UTIs was observed in the age group of 31-36 years (34.5%). Staphylococcus aureus (28%) and Pseudomonas aeruginosa (30%) were the most prevalent pathogens. High resistance rates were noted against ampicillin and azithromycin among gram-positive isolates, whereas gram-negative bacteria showed considerable resistance to ciprofloxacin. However, gentamicin displayed relative effectiveness across various pathogens. Conclusion: The study highlights a significant prevalence of antibiotic-resistant UTIs among pregnant women in the studied regions, with Staphylococcus aureus and Pseudomonas aeruginosa being the dominant pathogens. The findings call for an urgent need to implement effective antibiotic stewardship and screening programs during pregnancy to mitigate the risk of UTIs and their associated complications.

Trends of Antibacterial Interactions in Multidrug – Resistant Isolates: Exploring Resistance Phenotypes in the Ndé Division, West-Cameroon

Background: Reliable pieces of information concerning bacterial-antibiotic interactions are key assets for therapeutic management of bacterial diseases.&#x0D; Objective: The present study aimed at detecting phenotypic characteristics of bacterial resistance in multidrug-resistant isolates recovered from clinical specimens at the “Université des Montagnes” Teaching Hospital.&#x0D; Methods: The total of 226 isolates (142 Gram-negative rods and 84 Gram-positive cocci) were subjected to phenotypic screening of resistance mechanisms. All procedural steps were conducted according to standard protocols on bacterial susceptibility to antibiotics.&#x0D; Results: Primary pieces of information revealed high rates of resistant isolates, especially with beta-lactams and Trimethoprim/Sulfamethoxazole while Nitrofurantoin and Imipenem were most effective. Amongst Gram-negative rods, 56% expressed one enzymatic resistance mechanism and 12% expressed two against beta-lactams. Also, with extended spectrum beta-lactamases, high level cephalosporinases and inducible cephalosporinases most commonly observed. About 62% and 14% of Gram-positive cocci expressed constitutive and Clindamycin-inducible resistance, respectively. Decreased susceptibility to Ceftriaxone and Penicillin G was also recorded in suspect mutant isolates selected by these antibiotics. Potential synergetic and other antagonistic interactions were evenly detected.&#x0D; Conclusion: Overall, the data could represent reliable clue for advocacy about personalized combination therapy, then capacity building for routine affordable susceptibility tests in caretaking.

Assessing bacterial prevalence and resistance in paediatric meningitis: safeguarding the central nervous system.

Paediatric bacterial meningitis (PBM) represents a major contributor to childhood morbidity and mortality globally, with heightened susceptibility in low- and middle-income nations where antimicrobial resistance (AMR) is highly prevalent. Pakistan exemplifies this setting, with widespread antibiotic overuse driving AMR expansion. Thus, expediting PBM diagnosis and targeted antibiotic therapy is imperative yet challenged by the dynamic local epidemiology. This study aimed to delineate the recent bacterial etiologies and AMR profiles of PBM from a major Pakistani diagnostics laboratory to inform empirical treatment. This prospective observational investigation evaluated PBM epidemiology in patients under 18 years old admitted to the study hospital. Standard cerebrospinal fluid analysis identified bacterial pathogens and antibiotic susceptibility patterns. Among 171 PBM cases, 152 (88.9%) had bacterial isolates confirmed via culture. The cohort was 42.7% male with a mean age of 3 months. The most prevalent pathogens among infants younger than 3 months were Escherichia coli, Enterococcus faecium, and Staphylococcus epidermidis, contrasting with S. epidermidis, Streptococcus pneumoniae, and Staphylococcus hominis predominating in older children. Staphylococcal isolates exhibited considerable penicillin and erythromycin resistance but maintained vancomycin and linezolid susceptibility. Other resistance patterns varied. These findings highlight the pressing threat of paediatric AMR in Pakistan, underscoring the need for vigilant AMR surveillance and judicious antimicrobial use. This study provides a reference to current PBM epidemiology to guide context-specific empirical therapy.

Conjugation to Native and Nonnative Triscatecholate Siderophores Enhances Delivery and Antibacterial Activity of a β-Lactam to Gram-Negative Bacterial Pathogens.

Developing new antibiotics and delivery strategies is of critical importance for treating infections caused by Gram-negative bacterial pathogens. Hijacking bacterial iron uptake machinery, such as that of the siderophore enterobactin (Ent), represents one promising approach toward these goals. Here, we report a novel Ent-inspired siderophore-antibiotic conjugate (SAC) employing an alternative siderophore moiety as the delivery vector and demonstrate the potency of our SACs harboring the β-lactam antibiotic ampicillin (Amp) against multiple pathogenic Gram-negative bacterial strains. We establish the ability of N,N',N''-(nitrilotris(ethane-2,1-diyl))tris(2,3-dihydroxybenzamide) (TRENCAM, hereafter TC), a synthetic mimic of Ent, to facilitate drug delivery across the outer membrane (OM) of Gram-negative pathogens. Conjugation of Amp to a new monofunctionalized TC scaffold affords TC-Amp, which displays markedly enhanced antibacterial activity against the gastrointestinal pathogen Salmonella enterica serovar Typhimurium (STm) compared with unmodified Amp. Bacterial uptake, antibiotic susceptibility, and microscopy studies with STm show that the TC moiety facilitates TC-Amp uptake by the OM receptors FepA and IroN and that the Amp warhead inhibits penicillin-binding proteins. Moreover, TC-Amp achieves targeted activity, selectively killing STm in the presence of a commensal lactobacillus. Remarkably, we uncover that TC-Amp and its Ent-based predecessor Ent-Amp achieve enhanced antibacterial activity against diverse Gram-negative ESKAPE pathogens that express Ent uptake machinery, including strains that possess intrinsic β-lactam resistance. TC-Amp and Ent-Amp exhibit potency comparable to that of the FDA-approved SAC cefiderocol against Gram-negative pathogens. These results demonstrate the effective application of native and appropriately designed nonnative siderophores as vectors for drug delivery across the OM of multiple Gram-negative bacterial pathogens.

Molecular Characterization of Extended Spectrum β-Lactamase-Producing Escherichia coli: Insights into the O25b-ST131 Clone in Mexican Urinary Tract Infections

Background: The urgent need for antimicrobial research to address the escalating global challenge of β-lactam antibiotic resistance, particularly in Escherichia coli-induced urinary tract infections (UTI), is underscored by the increasing resistance to ciprofloxacin in Latin America. This issue has led to a heightened dependence on alternative therapeutics, such as cephalosporins. The identification of extended-spectrum β-lactamase (ESBL)-producing E. coli, notably the O25b-ST131 clone, adds complexity to UTI management. The prevalence of ESBL-producing E. coli varies globally due to factors including regional antimicrobial usage practices. Objectives: The goal of this study was to identify and molecularly characterize ESBL-producing E. coli isolates to identify the pandemic O25b-ST131 clone related to UTIs in one healthcare institution in Mexico. Methods: Bacterial species identification and antibiotic susceptibility tests were performed using the VITEK 2. The ESBL genes were identified using polymerase chain reaction (PCR). The E. coli genotyping was carried out by the phylogenetic group analysis and the O25b-ST131 identification. Results: A total of 86 unique E. coli isolates were confirmed as ESBL, and 75% were obtained from UTIs. The most prevalent β-lactamase genes were blaCTX-M (66%), blaTEM (8.1%), blaCTX-M/SHV (5.8%), blaCTX-M/TEM (4.6%), and blaSHV (2.3%). The B2 phylogroup was most prominent (54.4%), with 46.5% identified as a globally pandemic O25b-ST131 clone. No evident relationship was observed using random amplified polymorphic DNA (RAPD) between nosocomial and community-acquired infections in ESBL-producing E. coli isolates. Conclusions: The obtained findings highlight the significance of monitoring molecular epidemiology in antibiotic resistance profiles of the O25b-ST131 E. coli clone.