Antimicrobial Susceptibility Testing Research Articles

GPT-4-based AI agents-the new expert system for detection of antimicrobial resistance mechanisms?

The study titled "GPT-4-based AI agents-the new expert system for detection of antimicrobial resistance mechanisms?" is critically important as it explores the integration of advanced artificial intelligence (AI) technologies, like generative pre-trained transformer (GPT)-4, into the field of laboratory medicine, specifically in the diagnostics of antimicrobial resistance (AMR). With the growing challenge of AMR, there is a pressing need for innovative solutions that can enhance diagnostic accuracy and efficiency. This research assesses the capability of AI to support the existing two-step confirmatory process recommended by the European Committee on Antimicrobial Susceptibility Testing for detecting beta-lactamases in Gram-negative bacteria. By potentially speeding up and improving the precision of initial screenings, AI could reduce the time to appropriate treatment interventions. Furthermore, this study is vital for validating the reliability and safety of AI tools in clinical settings, ensuring they meet stringent regulatory standards before they can be broadly implemented. This could herald a significant shift in how laboratory diagnostics are performed, ultimately leading to better patient outcomes.

Presence of Enterococci in Cats with Urinary Tract Infections and Antibiotic Resistance Profiles

Background: Bacterial urinary tract infection (UTI) is one of the most common diseases in cats caused by an imbalance between the natural host defence mechanisms of the urinary tract and virulent bacteria. This study investigated the prevalence and antimicrobial susceptibility of enterococci isolated from cats presenting urinary tract problems to veterinary clinics in Istanbul. Methods: 100 urine samples were collected from cats by cystocentesis and plated on blood agar. Isolates found catalase and oxidase negative plated on Enterococcocel agar. After incubation, the isolates formed black colonies were tested by PCR using E. faecium and E. faecalis-specific primers. Then the antibiotic susceptibility of the isolates was determined. Result: Eight of the 100 isolates that formed black colonies on Enterococcosel agar were identified as Enterococcus spp. After PCR tests, six isolates were classified as E. faecalis, one isolate was classified as E. faecium and one isolate that did not form a band was classified as Enterococcus spp. As a result of the Kirby-Bauer disc diffusion method used to determine the antibiotic susceptibility of the isolates, most resistance was found to cephalothin (100%) and penicillin, erythromycin, clindamycin and tetracycline (87.5%). While vancomycin resistance was not observed in any isolate, the lowest resistance was to enrofloxacin and ciprofloxacin (33.3%). Multiple antibiotic resistance was observed in all (100%) isolates. The presence of multi-resistant enterococci in cats represents a significant health threat. Bacterial identification and antimicrobial susceptibility testing should always be performed in urinary tract infections to guide definitive diagnosis and treatment.

Antimicrobial Resistance Profiles of Escherichia coli and Staphylococcus spp. Isolated from Locally Produced Fish and Imported Fish Sold in the Centre Region of Cameroon

Antimicrobial resistance has emerged as a significant threat to global health, with the World Health Organization (WHO) classifying it among the top 10 public health threats. However, more epidemiological information is needed to support policy and stewardship programs. This study aimed to investigate the antimicrobial resistance profiles of Escherichia coli and Staphylococcus spp. isolated from locally produced and imported fish sold in markets in the Mfoundi Division of the Centre Region of Cameroon. A total of 11 Escherichia coli and 28 Staphylococcus spp. strains were isolated from the 100 fish samples collected in the study area. Antimicrobial susceptibility testing was performed for 16 antimicrobial agents using the disk diffusion method. Overall, multidrug resistance rates of 54.54% (95% confidence interval :26.9- 82.1) and 60.7% (95% confidence interval: 43.7-77.7) were obtained for Escherichia coli and Staphylococcus spp., respectively. The prevalence of antimicrobial resistant Escherichia coli and Staphylococcus spp. strains was significantly (p<0.05) higher in locally produced fish (18.6%; 32.6%) than in imported fish (5.3%; 24.6%). According to the WHO Essential Medicines List Access, Watch, and Reserve (AWaRe) classification, the antimicrobial resistance profile of Escherichia coli strains isolates ranged from 5% to 45% for antimicrobials classified as Access and Watch. For Staphylococcus spp., the antimicrobial resistance profile ranges from 7% to 60% for drugs categorized as Access, whereas it ranges from 25% to 100% for drugs belonging to the Watch category. This study revealed that locally produced fish were more contaminated by antimicrobial resistant Escherichia coli and Staphylococcus spp. than imported fish. The continuous awareness of fish farmers about the appropriate use of aqua drugs is one of the cornerstones for reducing the risk of antimicrobial resistance related to public health.

A multicenter evaluation of a novel microfluidic rapid AST assay for Gram-negative bloodstream infections.

Increasing antimicrobial resistance underscores the need for new diagnostic solutions to guide therapy, but traditional antimicrobial susceptibility testing (AST) is often inadequate in time-critical diseases such as sepsis. This work presents a novel and rapid AST system with a rapid turnaround of results, which may help reduce the time to guided therapy, possibly allowing early de-escalation of broad-spectrum empirical therapy as well as rapid adjustments to treatments when coverage is lacking.

Bacterial Contamination of Donor Blood Units in a Ghanaian Blood Bank: A Critical Concern for Transfusion Safety

Abstract Introduction/Objective Background: Blood transfusions, while life-saving, pose a significant risk to patient safety, with transfusion-associated bacterial sepsis emerging as a persistent and potentially fatal threat. The prevalence and severity of bacterial contamination in donor blood units necessitate regular surveillance to ensure safe and effective transfusion therapy. Aim This study aimed to identify and assess the susceptibility of bacterial isolates in whole blood donor units at the blood bank of Cape Coast Teaching Hospital in the Central Region of Ghana. Methods/Case Report Method(s): One hundred and three (103) units of stored whole blood units, declared safe for transfusion (testing negative for HIV I&amp;II, HBsAg, HCV, and syphilis), were inoculated into Brain Heart Infusion Broth and incubated for 24 hours. The inoculated broths were then cultured on MacConkey agar (MAC), Chocolate agar (CHOC), and Blood agar. Gram-negative and Gram-positive isolates were identified using standard biochemical tests. Antimicrobial susceptibility testing was performed using the disc diffusion method. Results (if a Case Study enter NA) Results: Of the 103 donor blood units tested, 33 (32.03%) were found to have bacterial isolates. Gram-positive organisms accounted for 67.14% of the isolates, including Coagulase negative Staphylococcus, Bacillus spp, and S. aureus. Gram-negative bacteria constituted 32.86% of the isolates, with Citrobacter freundii, Serratia marcescens, E. coli, and Providencia stuartii identified. Notably, 62.9% of the bacterial isolates were skin commensals, while 25.7% were of enteric origin and 11.4% were of nosocomial origin. Resistance to commonly used antibiotics varied among isolates, with Coagulase-negative Staphylococcus exhibiting resistance to amoxicillin (92.86%) and erythromycin (76.19%), while Citrobacter freundii showed resistance to levofloxacin (75.00%) and ofloxacin (75.00%). Conclusion Conclusion(s): The high incidence of bacterial contamination in donor blood units highlights the need for improved phlebotomy procedures and decontamination practices at blood banks in Ghana to reduce the risk of sepsis in transfusion recipients. Furthermore, this study provides valuable information regarding antibiotic resistance patterns in bacterial isolates, emphasizing the importance of antibiotic stewardship in Ghana. In conclusion, this study underscores the urgency of addressing bacterial contamination in donor blood units in Ghanaian blood banks to enhance transfusion safety.

The point mutation A1387G in the 16S rRNA gene confers aminoglycoside resistance in Campylobacter jejuni and Campylobacter coli.

Thermotolerant Campylobacter spp. are the most frequent cause of foodborne bacterial diarrhea and high-priority antibiotic-resistant pathogens, according to the World Health Organization (WHO). Monitoring revealed current low prevalence of gentamicin resistance in European Campylobacter spp. isolates but substantial presence of gentamicin modifying genes circulating globally. Using a combined approach of natural transformation and whole-genome sequencing, we revealed a novel gentamicin resistance mechanism, namely the point mutation A1387G in the 16S rRNA gene, originally identified in a C. coli isolate from turkey caecal content. The transformation rate of the resistance using genomic DNA of the resistant donor to sensitive recipient C. jejuni and C. coli was ~2.5 log10 lower compared to the control rpsL-A128G point mutation conferring streptomycin resistance. Antimicrobial susceptibility tests showed cross-resistance to apramycin, kanamycin, and tobramycin, with transformants exhibiting more than 4- to 8-fold increased MICs to apramycin and tobramycin and over 64-fold higher MICs to kanamycin compared to wild-type isolates. Although transformants showed 177-1,235 variations relative to the recipient, only the A1387G point mutation in the 16S rRNA was in common. This mutation was causal for resistance, as transformation of a 16S rRNA_A1387G PCR fragment into susceptible isolates also led to resistant transformants. Sanger sequencing of the 16S rRNA genes and Oxford nanopore whole-genome sequencing of transformants identified clones harboring either all three copies with A1387G or a mixed population of wild-type and mutated 16S rRNA gene alleles. Within 15 passages on non-selective medium, transformants with mixed populations of the 16S rRNA gene copies partially reverted to wild type, both geno- and phenotypically. In contrast, transformants harboring the A1387G point mutation in all three 16S rRNA gene copies kept full resistance within at least 45 passages. We speculate that partial acquisition and rapid loss of the point mutation limited its spread among C. spp. isolates. In-depth knowledge on resistance mechanisms contributes to optimal diagnosis and preventative measures.

The Burden of Acinetobacter baumannii Among Pet Dogs and Cats with Respiratory Illness Outside the Healthcare Facilities: A Possible Public Health Concern.

Background: Researchers paid more attention to nosocomial Acinetobacter baumannii in veterinary hospitals worldwide; however, the research scope toward community-acquired A. baumannii infections among animals is largely ignored. Therefore, the current study aimed to investigate the role of diseased dogs and cats suffering from respiratory illness in transmission of community-acquired A. baumannii infection and its public health threat. Materials and methods: Oral swabs were collected from 154 pet animals with respiratory signs, including 80 cats and 74 dogs (outpatient visits). The obtained swabs were cultured on CHROMagar™ MH Orientation media for isolation of A. baumannii, and identification of suspected isolates was conducted via Gram staining, conventional biochemical tests, and molecular detection of the blaOXA-51-like gene. Antimicrobial susceptibility testing of A. baumannii isolates was carried out using the disc diffusion method. Results: Overall, 10 (6.5%) out of 154 diseased pet animals were positive for A. baumannii, where 6 (8.1%) and 4 (5%) dogs and cats were positive, respectively. Multidrug-resistant (MDR) A. baumannii was found in 3.9% of the examined animals. The phylogenetic tree analysis revealed that the obtained sequences from dogs and cats were closely related to human and animal sequences. Conclusion: The occurrence of MDR A. baumannii among dogs and cats suffering from respiratory illness highlights the potential role of pet animals in the dissemination of MDR A. baumannii in the community.

Repurposing MALDI-TOF MS for effective antibiotic resistance screening in Staphylococcus epidermidis using machine learning

The emergence of Staphylococcus epidermidis as a significant nosocomial pathogen necessitates advancements in more efficient antimicrobial resistance profiling. However, existing culture-based and PCR-based antimicrobial susceptibility testing methods are far too slow or costly. This study combines machine learning with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) to develop predictive models for various antibiotics using a comprehensive dataset containing thousands of S. epidermidis isolates. Optimized machine learning models utilized feature selection and achieved high AUROC scores ranging from 0.80 to 0.95 while maintaining AUPRC scores up to 0.97. Shapley Additive exPlanations were employed to analyze relevant features and assess the significance of corresponding protein biomarkers while also verifying that predictive power was derived from the detection of proteins rather than noise. Antimicrobial resistance models were validated externally to evaluate model performance outside the original data collection site. The approaches and findings in this study demonstrate a significant advancement in rapid, cost-effective antimicrobial resistance profiling, offering a promising solution for improving treatments for nosocomial infections and being potentially applicable to other microbial pathogens in the future.

Green tea (Camellia sinensis) leaf extract inhibits the activity of β-lactamases

The most emerging resistance mechanism against β-lactam antibiotics present in bacteria is the production of β-lactamases. The aim of this study was to explore the phytocompounds of Camellia sinensis (green tea) that can inhibit the activity of β-lactamases. Moreover, the antibacterial effect of its extract with a combination of antibiotics against resistant bacterial strains was also appraised. In silico docking was carried out against the resistance causing enzymes such as AmpC and SHV-1. Antimicrobial susceptibility testing against bacterial strains, i.e., Klebsiella pneumoniae and Escherichia coli, was performed. Then, for exploring the synergistic effects, both antibiotics and green tea extract were applied in combination. The docking studies revealed that the inhibitors like epigallocatechin gallate with AmpC, and myricetin with SHV-1 enzyme displayed high binding affinities of -8.2 kJ/mol, and -7.5 kJ/mol, respectively. The in vitro combination of C. sinensis extract with ampicillin and penicillin also potentiated the antibacterial activity of these antibiotics. Thus, the study elucidated that the phytochemicals of C. sinensis could inhibit β-lactamases produced by the pathogens. Also, it has enhanced antimicrobial effects when combined with antibiotics.

Resistance patterns, virulence determinants, and biofilm genes of multidrug-resistant Pseudomonas aeruginosa isolated from fish and fish handlers

Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic bacterium that is widely distributed in aquatic environments and causes major economic losses in fish and public health hazards.This study aimed to identify the occurrence of P. aeruginosa in samples collected from fish and fish handlers, and to investigate the antimicrobial susceptibility, virulence determinants, and biofilm genes of P. aeruginosa isolates. A total of 276 samples were cross-sectionally collected from Nile tilapia (53), Golden grey mullet (52), Mediterranean horse mackerel (50), Striped red mullet (71), and fish handlers (50) at five different retail fish markets in Damietta Governorate, Egypt. Pseudomonas species (spp.) were biochemically identified in 57.9% of the total examined samples. Peudomonas aeruginosa were the most prevalent species isolated from the fish and human samples via PCR technique. Peudomonas aeruginosa isolates exhibited full resistance (100%) to tobramycin (TOB), gentamicin (CN), and colistin (CL), with a high level of susceptibility (88.5%) to imipenem (IPM) using the disk diffusion method. Most P. aeruginosa isolates (84.6%) exhibited drug resistance, with 61.5% were multidrug resistance (MDR) and 23.1% were extensive drug resistance (XDR). Most isolates had at least four virulence-associated genes (lasB, toxA, exoU, and oprL) and three biofilm genes (psIA, peIA, and lasR) by using uniplex PCR. The lasI, and rhlR Quorum Sensing (QS) genes were identified in 84.6% and 61.5% in the examined P. aeruginosa isolates, respectively. The highest mortality rate in Nile tilapia experimentally infected with P. aeruginosa isolate encoding most of virulent genes. Multivariate analyses revealed high heterogeneity among the examined isolates. This study revealed the emergence of virulent and drug resistant P. aeruginosa isolates in fish, poses high risks to consumers and food. Thus, strict hygienic measures should be considered when catching, handling, and storing fish, in addition to the routine application of antimicrobial susceptibility testing.

High Mortality Rates and Antimicrobial Resistance in Children with Invasive Bacterial Infections in a Tertiary Care Facility in West Africa

Abstract Background Childhood data on infection mortality and antimicrobial resistance in Sub-Saharan Africa are emerging but remain limited. The University of Maryland Center for Vaccine Development (CVD) and CVD-Mali have been conducting a prospective observational study at L’Hopital Gabriel Toure (HGT), a referral hospital in Bamako, Mali, since 2002 to identify causes of invasive bacterial infections (IBI) in children. These data have been used to initiate vaccination programs to decrease the burden of Haemophilus influenzae type b and Streptococcus pneumoniae. Additional demographic and antimicrobial susceptibility data have been collected since 2021, allowing for more detailed resistance and mortality analyses. Methods All children presenting to HGT are screened. Children ages 0-15 years with temperature of at least 39 degrees Celsius and/or suspicion of IBI are eligible. Eligible children have blood cultures collected with additional site-specific cultures when focal infection is suspected. Cultures are performed using the Bactec system; when positive, Gram staining, sub-culturing, and antimicrobial susceptibility testing (by disk diffusion using standard methods) are performed. Organisms thought to be contaminants are excluded. American type culture collection strains are utilized for quality control. Results Between 1/14/2021 and 9/14/2023, 28703 patients were screened. 2156 patients were included. 212 patients (10%) had 235 pathogens isolated. Gram positive organisms were most frequently isolated (N=112), followed by Gram negative Enterobacterales (N=81), non-Enterobacterales Gram negatives (N=36), and yeast (N=6). Staphylococcus aureus was the most frequently isolated Gram positive organism (59 bloodstream isolates, 2 joint isolates, 2 subcutaneous isolates) followed by S.pneumoniae (10 bloodstream isolates, 17 cerebrospinal fluid isolates, 1 joint isolate) and Enterococcus species (16 bloodstream isolates). Klebsiella pneumoniae (28 bloodstream isolates, 2 cerebrospinal fluid isolates) and Escherichia coli (18 bloodstream isolates, 3 cerebrospinal fluid isolates, 2 subcutaneous isolates) were the most frequently isolated Gram negative Enterobacterales, with Pseudomonas species most common among non-Enterobacterales Gram negative organisms (16 bloodstream isolates, 1 cerebrospinal fluid isolate). Mortality rates in both culture-positive and culture-negative patients were high (52% and 28%, respectively), with greater than 50% of deaths occurring within 48 hours in both groups. 88% of Gram negative Enterobacterales were ceftriaxone resistant or intermediate, with 56% ciprofloxacin resistant or intermediate; 55% of isolates were resistant or intermediate to both. 71% of isolates were gentamicin resistant. Imipenem resistance remained low, with 91% of isolates retaining sensitivity. 24% of S. aureus isolates were oxacillin resistant and 34% of isolates were resistant or intermediate to trimethoprim/sulfamethoxazole. 100% of S. aureus isolates tested (14/60) retained sensitivity to clindamycin. Only 54% of pneumococcal isolates had positive oxacillin screens, implying frequent penicillin resistance, and only 60% of enterococcal species were ampicillin sensitive, although 92% retained vancomycin sensitivity. Conclusion We found higher mortality rates in our study than in similar studies; the contribution of issues such as limited access to advanced supportive care and delay in presentation is an area for further study. The high frequency of multidrug-resistant organisms is alarming, suggesting an urgent need to investigate underlying contributing factors, increase access to affordable broad-spectrum antibiotics, and create robust antimicrobial stewardship programs.

Overall status of carbapenem resistance among clinical isolates of Acinetobacter baumannii: a systematic review and meta-analysis.

Resistance to carbapenems, the first-line treatment for infections caused by Acinetobacter baumannii, is increasing throughout the world. The aim of the present study was to determine the global status of resistance to carbapenems in clinical isolates of this pathogen, worldwide. Electronic databases were searched using the appropriate keywords, including: 'Acinetobacter' 'baumannii', 'Acinetobacter baumannii' and 'A. baumannii', 'resistance', 'antibiotic resistance', 'antibiotic susceptibility', 'antimicrobial resistance', 'antimicrobial susceptibility', 'carbapenem', 'carbapenems', 'imipenem', 'meropenem' and 'doripenem'. Finally, following some exclusions, 177 studies from various countries were included in this study. The data were then subjected to a meta-analysis. The average resistance rate of A. baumannii to imipenem, meropenem and doripenem was 44.7%, 59.4% and 72.7%, respectively. A high level of heterogeneity (I2 > 50%, P value < 0.05) was detected in the studies representing resistance to imipenem, meropenem and doripenem in A. baumannii isolates. Begg's and Egger's tests did not indicate publication bias (P value > 0.05). The findings of the current study indicate that the overall resistance to carbapenems in clinical isolates of A. baumannii is relatively high and prevalent throughout the world. Moreover, time trend analysis showed that the resistance has increased from the year 2000 to 2023. This emphasizes the importance of conducting routine antimicrobial susceptibility testing before selecting a course of treatment, as well as monitoring and controlling antibiotic resistance patterns in A. baumannii strains, and seeking novel treatment options to lessen the emergence and spread of resistant strains and to reduce the treatment failure.

Dual-modal detection of antimicrobial susceptibility in pathogenic bacteria based on the high-throughput microfluidic platform

For pathogenic bacterial infectious diseases such as sepsis, accurate and rapid antimicrobial susceptibility testing (AST) plays an important role in improving antimicrobial screening and clinical outcomes. Traditional culture-based AST assays have the limitations of time-consuming, labor-intensive, expensive, and consuming reagents. In this work, a simple, fast, high-throughput microfluidic platform integrated with isolation, identification, and detection functions was designed for antibiotic susceptibility analysis in pathogenic bacteria. For the above purpose, MnO2@ZIF-90 nanoprobes with dual functions of nanozyme and fluorescence were prepared for visual eye or RGB analysis through a smartphone APP. More importantly, the redox activity of bacterial membrane in active pathogenic bacteria could decompose the MnO2 of MnO2@ZIF-90 nanoprobes and reduce the enzyme-like activity, which weakens the colorimetric signal of Timebox. Meanwhile, the ATP released from active pathogenic bacteria further triggered the breakdown of the inner ZIF-90 layer, generating a fluorescence signal. Therefore, a dual detection combining colorimetric and fluorescence was used to perform more accurate and reliable antibiotic susceptibility analysis of pathogenic bacteria. With the proposed microfluidic platform, a low detection of 10 CFU mL−1 bacteria and fast AST results were achieved within 5 min. The clinical applicability of the platform was further demonstrated through the analysis of clinical samples. This work provides a low-cost, easy-to-operation, fast-response, and high-throughput platform for the AST assays in pathogenic bacterial infectious diseases such as sepsis.

Lactococcus garvieae as a Novel Pathogen in Cultured Pufferfish (Takifugu obscurus) in China

In October 2023, a disease outbreak in pufferfish (Takifugu obscurus) farms in Zhongshan City, Guangdong, China, caused high mortality. Diseased fish (mean length: 15 ± 1 cm) exhibited swimming disorders, fin rot, hemorrhage, and an enlarged spleen. Histopathological observations generally revealed inflammation, necrosis, and congestion in the spleen, kidneys, and brain tissues. The most severe pathological changes included interstitial edema and tubular atrophy in the kidneys, hemosiderin deposition in the spleen, massive red blood cell infiltration, and a decrease in lymphocytes. A single strain of bacteria (Tol-1) was isolated from the diseased pufferfish and identified as a Gram-positive streptococcus strain, exhibiting α-hemolysis on sheep blood agar plates. Through biochemical characterization, 16S rDNA sequencing, morphological analysis, and specific primer-based identification, the Tol-1 strain was identified as Lactococcus garvieae, serotype I. Antimicrobial susceptibility testing indicated that Tol-1 was sensitive to Chloramphenicol, Ampicillin, Cephalexin, and Doxycycline, but resistant to Kanamycin, Gentamicin and Ciprofloxacin. In addition, 15 common virulence factors were detected in the Tol-1 strain, including adhPav, adhPsaA, adhC I–II, adh, and hly 1–3. Pufferfish (mean length: 17 ± 1 cm) subjected to artificial infection via intraperitoneal injection (IP) with the Tol-1 strain exhibited clinical symptoms and histopathological damage similar to those observed in naturally infected fish. An infection dose of 1 × 105 CFU/fish resulted in 80% mortality. The study fulfilled Koch’s postulates, indicating that the disease outbreak in pufferfish was caused by L. garvieae, which exhibited a high mortality rate in pufferfish despite the subtle clinical symptoms. These results serve as a warning for pufferfish farming areas and provide a scientific basis for future prevention and control efforts.

Occurrence of Extended-spectrum β-lactamase (ESBL) and Carbapenemase-producing Escherichia coli isolated from Childhood Diarrhoea in Yaoundé, Cameroon

IntroductionExtended-spectrum β-lactamase (ESBL)-producing pathogenic E. coli is a global public health issue, especially in sub-Saharan African countries such as Cameroon. It contributes to increase significantly hospital length of stay, morbidity, mortality and economic costs because of treatment failures. This study aims at determining the resistance background and virulence profiles of ESBL-E. coli isolates among childhood diarrhoea during the cholera outbreak occuring in Yaoundé, Cameroon.Materials and methodsDuring a four-month periods, from March 1st to June 30th, 2023, a total of 84 stool samples were collected from 90 under five children presenting clinical signs of gastroenteritis and attending four hospitals in Yaoundé, Cameroon. Bacterial identification was done using API20E and antimicrobial susceptibility test was performed using the Kirby-Bauer disc diffusion method. After extraction, genomic DNA was subjected to conventional and multiplex polymerase chain reaction methods (PCRs) for detection of resistance and virulence genes. Statistical analysis was performed using Epi info™ (7.2.5.0). Statistical significance was considered at a p-value < 0.05.ResultsOut of 150 patients contacted, 90 patients were enrolled, 84 samples were collected, 52.38%(44/84) and 3.57%(03/84) were confirmed as extended-spectrum β-lactamase and carbapenemase-producing E. coli respectively. The risk factors were analyzed, and children who drank natural fruit juice (OR: 0.4, p-value: 0.03) were found to be significantly associated with ESBL-producing E. coli. The ESBL-producing E. coli isolates showed a high level of resistance to amoxicillin-clavulanic acid, cefotaxime, ceftazidime, cefepime, colistin, and tetracycline. The blaCTX−M was more prevalent ß-lactamase resistance gene. The tetracycline resistance genes tet(A) and tet(B) were also detected. The most important virulence genes detected were FimH (81.81%) and papA (79.54%).ConclusionThese findings suggest implementing routine surveillance and screening for antimicrobial resistance among children under five. Antimicrobial stewardship strategies (ASP) need to be implemented to curb the emergence and dissemination of ESBL-producing E. coli. In addition, a national surveillance program for antimicrobial resistance needs to be implemented at local and regional levels in order to reduce morbidity in Cameroon.

In vitro activity assessment of cefiderocol against Enterobacterales, Pseudomonas aeruginosa, and Acinetobacter spp., including β-lactam nonsusceptible molecularly characterized isolates, collected from 2020 to 2021 in the United States and European hospitals.

This study reports the activity of cefiderocol against Enterobacterales, Pseudomonas aeruginosa, and Acinetobacter spp. isolates collected from the United States and Europe, including Israel and Turkey, from 2020 to 2021. Among Enterobacterales, 2.8% were carbapenem nonsusceptible (CNSE); cefiderocol inhibited 96.6%/85.1% [Clinical Laboratory Standards Institute (CLSI)/European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints] of these isolates. Imipenem-relebactam, meropenem-vaborbactam, and ceftazidime-avibactam displayed susceptibilities lower than cefiderocol against CNSE isolates (67.4-84.6% susceptible, CLSI). Cefiderocol was the only agent active against CNSE isolates carrying metallo-β-lactamase (MBL) carbapenemase or multiple carbapenemase genes (84.6%-92.3% susceptible, CLSI). Approximately 18% of carbapenem-susceptible Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis carried extended-spectrum-β-lactamases and/or plasmid-borne AmpC-encoding genes; cefiderocol inhibited 99.8%-100.0% (CLSI) of these genotypic groups. Multi-drug resistance (MDR) phenotypes were observed in 16.9% and 52.5% of P. aeruginosa and A. baumannii-calcoaceticus isolates, respectively. Carbapenemase genes were rare (4.9%) among cephalosporin and/or carbapenem nonsusceptible P. aeruginosa, compared to 87.6% carriage in A. baumannii-calcoaceticus, respectively. Against the MDR and carbapenemase-carrying P. aeruginosa and A. baumannii-calcoaceticus subsets, cefiderocol was active against 98.6%/98.7% and 97.1%/97.4% (CLSI), respectively. Only 69 isolates (0.3%) across all species groups were identified as cefiderocol nonsusceptible per CLSI criteria (>4 mg/L). Cefiderocol was the most active agent in vitro against Enterobacterales, P. aeruginosa, and Acinetobacter spp., with uniform activity against all phenotypic- and genotypic-resistant subsets. Coupled with the low incidence of nonsusceptibility observed across species groups, these results demonstrate cefiderocol as an important option for treating infections caused by pathogens with diverse mechanisms of resistance in US and European hospitals.IMPORTANCEThe worldwide spread of multi-drug-resistant Pseudomonas aeruginosa and carbapenem-resistant Enterobacterales and Acinetobacter spp. poses a serious challenge in healthcare settings as infections caused by these organisms are commonly refractory to many frontline therapeutic agents. Multiple global health organizations highlighted these pathogens as critical priorities for new antibiotic development, thus necessitating continued surveillance of the activities of currently available antimicrobial agents and circulating mechanisms of resistance. To meet this need, this study phenotypically and genotypically characterized priority Gram-negative pathogens collected from patients in US and European hospitals to examine the activity of cefiderocol and other currently available treatment options, including carbapenems and β-lactam-β-lactamase inhibitor combinations. The results presented here provide a detailed perspective to healthcare practitioners of cefiderocol's broad applicability, manifested in high activity and low nonsusceptibility rates, across phenotypic and genotypic organism groups relative to other agents and further support its use against the most intransigent infections.

Integrating whole genome sequencing and machine learning for predicting antimicrobial resistance in critical pathogens: a systematic review of antimicrobial susceptibility tests.

Infections caused by antibiotic-resistant bacteria pose a major challenge to modern healthcare. This systematic review evaluates the efficacy of machine learning (ML) approaches in predicting antimicrobial resistance (AMR) in critical pathogens (CP), considering Whole Genome Sequencing (WGS) and antimicrobial susceptibility testing (AST). The search covered databases including PubMed/MEDLINE, EMBASE, Web of Science, SCOPUS, and SCIELO, from their inception until June 2024. The review protocol was officially registered on PROSPERO (CRD42024543099). The review included 26 papers, analyzing data from 104,141 microbial samples. Random Forest (RF), XGBoost, and logistic regression (LR) emerged as the top-performing models, with mean Area Under the Receiver Operating Characteristic (AUC) values of 0.89, 0.87, and 0.87, respectively. RF showed superior performance with AUC values ranging from 0.66 to 0.97, while XGBoost and LR showed similar performance with AUC values ranging from 0.83 to 0.91 and 0.76 to 0.96, respectively. Most studies indicate that integrating WGS and AST data into ML models enhances predictive performance, improves antibiotic stewardship, and provides valuable clinical decision support. ML shows significant promise for predicting AMR by integrating WGS and AST data in CP. Standardized guidelines are needed to ensure consistency in future research.

How Restrictive Legislation Influences Antimicrobial Susceptibility in Selected Bacterial Isolates from the Canine Vagina.

Antimicrobial stewardship is one of the cornerstones in the battle against antimicrobial resistance. Restrictive legislation aims to foster antimicrobial stewardship. Prophylactic prescription of antimicrobials is still a widespread practice in canine breeding management to prevent suspected infectious infertility. The aim of this study was to evaluate the efficacy of restrictive legislation in Germany (Veterinary Home Pharmacy Ordinance, TÄHAV) based on resistance profiles of common bacterial isolates from the vaginal tract by comparing the resistance situation before (time frame (TF1)) and after (TF2) its amendment. In total, results of 13,373 antimicrobial susceptibility tests of bacterial isolates of Escherichia coli (n = 5209), beta-hemolytic streptococci (n = 4010), and Staphylococcus (Staph.) intermedius group (n = 4154) derived from canine vaginal swabs were assessed. Antimicrobial susceptibility testing was performed on pure cultures using the broth microdilution method. Susceptibility to selected antimicrobials was evaluated. Susceptibility of Escherichia coli generally increased within TF2 with, however, a significant increase in the number of non-susceptible isolates to cefalexin (p < 0.0001). Beta-hemolytic streptococci exhibited good susceptibility to most antimicrobials. Susceptibility developed ambivalently within the Staphylococcus intermedius group. Despite an overall positive effect of increased susceptibility, an increase in non-susceptibility to single antimicrobials was detected, possibly indicating a need for refinement of the legislation.

Quantifying aminoglycoside resistance in extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales clinical isolates: a retrospective cohort study.

Aminoglycoside resistance is frequently detected in extended-spectrum-beta-lactamase (ESBL)-producing Enterobacterales (ESBL-PE), questioning the appropriateness of aminoglycosides as empiric therapy in patients with suspected ESBL-PE infections. Therefore, we aimed to evaluate the frequency of aminoglycoside resistance in patients harbouring ESBL-PE and identify patient-related risk factors associated with aminoglycoside resistance to facilitate early detection of at-risk patients. This retrospective single-centre cohort study included hospitalised patients aged ≥18 years with an ESBL-PE-positive sample between January 2016 and December 2018. Aminoglycoside resistance was defined according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) clinical breakpoints for Enterobacterales for the current year of testing. Five hundred forty-four patients met the eligibility criteria, of which 240 (44.1%) harboured aminoglycoside-resistant ESBL strains. Identification of ESBL-Klebsiella pneumoniaewas significantly associated with aminoglycoside resistance (odds ratio [OR] = 2.64, 95% confidence interval [CI] = 1.65-4.21, p <0.001) and an international travel history within the past 12 months was marginally associated with aminoglycoside resistance (OR = 1.51, 95% CI = 0.95-2.42, p = 0.084). In a low ESBL endemicity setting, aminoglycoside resistance in patients harbouring ESBL-PE is common, especially ESBL-K. pneumoniae, and needs to be considered in clinicians' decision-making regarding empiric therapy regimens.

Deoxyshikonin: a promising lead drug grass against drug resistance or sensitivity to Helicobacter pylori in an acidic environment.

Helicobacter pylori (H. pylori) is closely associated with the diseases such as gastric sinusitis, peptic ulcers, and gastric adenocarcinoma. Its drug resistance is very severe, and new antibiotics are urgently needed. Nine comfrey compounds were screened by antimicrobial susceptibility testing, among which deoxyshikonin had the best inhibitory effect, with a minimum inhibitory concentration (MIC) of 0.5-1 µg/mL. In addition, deoxyshikonin also has a good antibacterial effect in an acidic environment, it is highly safe, and H. pylori does not readily develop drug resistance. Through in vivo experiments, it was proven that deoxyshikonin (7 mg/kg) had a beneficial therapeutic effect on acute gastritis in mice infected with the multidrug-resistant H. pylori BS001 strain. After treatment with desoxyshikonin, colonization of H. pylori in the gastric mucosa of mice was significantly reduced, gastric mucosal damage was repaired, inflammatory factors were reduced, and the treatment effect was better than that of standard triple therapy. Therefore, deoxyshikonin is a promising lead drug to solve the difficulty of drug resistance in H. pylori, and its antibacterial mechanism may be to destroy the biofilm and cause an oxidation reaction.