Beta-lactamase Research Articles

Monte Carlo simulation for dosage optimization of the best available therapy for bloodstream infections secondary to carbapenemase-producing Klebsiella pneumoniae in critically ill patients

ObjectivesWe aimed to use Monte Carlo simulation, based on pharmacokinetic/ pharmacodynamic (PK/PD) targets, to investigate and determine the optimal dosage of the available combination therapies for carbapenem-resistant Klebsiella pneumoniae (CRKP) in critically ill patients. MethodsWe collected CRKP clinical isolates from Phramongkutklao Hospital between October 2020 and June 2022. A molecular study of resistant genes was performed using polymerase chain reaction (PCR). Broth microdilution checkerboards were used to evaluate the mono- and synergistic antibiotic activities. Monte Carlo simulation was used to determine the optimal antibiotic regimens, based on the probability of target achievement (PTA) and cumulative fraction of response (CFR). ResultsThe 54 CRKP isolates were resistant to tigecycline (100%), colistin (75.9%), amikacin (70.4%), and gentamicin (63.0%). The most common carbapenemase genotype was blaoxacillinases (OXA)-48-like (42.6%), followed by blaNew Delhi metallo beta lactamase (NDM) (29.6%) and coexistence of blaOXA-48-like and blaNDM (22.2%). Based on the PTA, synergistic and additive activities against CRKP isolates were observed with appropriate dosages of tigecycline–colistin (67.9%), tigecycline–gentamicin (62.2%), and tigecycline–amikacin (51.4%). ConclusionsTigecycline–colistin was the best available combination therapy for critically ill patients with CRKP, especially NDM. When used in combination with tigecycline, a colistin creatinine clearance (CrCl) of <90 mL/min can raise the CFR target and less nephrotoxicity.

Prevalence and Antibiotic Susceptibility Profile of Uropathogenic ESBL-producing Klebsiella pneumoniae in Keffi Metropolis, Nigeria

Urinary tract infection (UTI) remains the most common bacterial infection in humans despite the widespread availability of antibiotics. Exteded spectrum beta-lactamase production is an important mechanism of antibiotic resistance in the Enterobacteriaceae. Antibiotic resistance is a rising dilemma of significant implications on global public health. Few data exist for the prevalence and trends of Klebsiella pneumoniae antibiotic resistance in Keffi metropolis Nigeria. This study was done to determine the prevalence of ESBL-producing K. pneumoniae as well as its antibiotic susceptibility pattern regarding some predisposing factors. Aim: This study was carried out to determine the prevalence and antibiotic susceptibility pattern of uropathogenic K. pneumoniae in Keffi metropolis, Nigeria. Methodology: The current study was a carried out in Keffi, Nasarawa state, Nigeria from July to October 2024. It was a cross-sectional study comprising of 160 early morning urine samples randomly collected from consenting participants in the six selected hospitals. Isolation and identification of K. pneumoniae was done using standard microbiological methods. The antibiotic susceptibility profile of isolates was carried out using the Kirby-Bauer disc diffusion method and interpretation was done following the Clinical and Laboratory Standards Institute protocol. Results obtained in this study were analysed using Smith’s Statistical Package (version 2.8, California, USA) and P value of ≤ 0.05 was considered statistically significant. Results: The result of this study revealed an overall prevalence of 20/160 (12.5%). The highest prevalence of the isolate was seen in females 14(8.75) compared to males 6 (3.75%), while the highest prevance regarding age was recorded among the 15-34 age group 12 (7.5%) while the least was recorded among those greater than 65 years 0 (0%). Furthermore, the highest number of isolate was recorded at FMCK 7 (4.4%) followed jointly by GHK and PHC TK 4 (2.5%) with PHC, KP and PHC AJ 1 (0.63%) beign the least respectively. There was a high level of resistance to ceftazidime 20 (100%), followed jointly by ceftriaxone, cefurexime and treptomycin 19 (95%) and augmentin 18 (90%) but low to amoxicillin 6 (30%) and ofloxacin 6 (30%) respectively. Most of the isolates tested were multidrug resistant and all were extended spectrum beta lactamase (ESBL) producing. Conclusion: The relatively high detection rate of multidrug resistant uropathogenic K. pneumoniae in this study calls for concern. More concerning is the isolation from primary health care centers (PHCs) signifying the importance of universal health coverage and the place of PHCs in antimicrobial stewardship (AMS) programs as one of the strategies to control the spread of antimocrobial resistance.

First-Genome Sequence Data of an Alcaligenes nematophilus Strain EBU-23 Encoding bla Gene Implicated in Acute Childhood Gastroenteritis.

Although an environmental contaminant, Alcaligenes sp. are now increasingly reported in clinical infections. Here, we present a whole-genome sequence of an extended spectrum beta-lactamase (ESBL) Alcaligenes nematophilus strain EBU-23 encoding beta-lactamase, bla gene, isolated from the stool of a hospitalized infant with acute gastroenteritis in a tertiary hospital in Nigeria. Antibiotics susceptibility test revealed that the isolate was resistant to the β-lactams, cephalosporins, and penicillin, β-lactam combination, and the fluoroquinolones. Genomic analysis exposed the presence of a class A beta-lactam hydrolase gene and multiple multidrug efflux permease which may be responsible for the beta-lactamase and multidrug resistance observed with the isolate. To the best our knowledge, we describe the first whole-genome sequence of a multidrug-resistant A. nematophilus implicated in acute childhood gastroenteritis in Nigeria.

Nursing bibliometric analysis of wound infections.

This paper aims to perform a bibliometric analysis of research pertaining to the nursing care of infected wounds. It also aims to examine the current focal points and trends in research development. The paper offers research references that may be useful for practitioners interested in related areas. The Web of Science Core Collection database was queried for publications pertaining to infected wound care. Publication trends and proportions were analyzed using Graphpad Prism v8.0.2. CiteSpace (6.2.4R [64-bit]) and VOSviewer (version 1.6.18) were employed to assess the literature and conduct mapping. The Web of Science Core Collection database contains 3868 literature related to wound infection care, including 3327 articles and 541 reviews. The literature concerned 117 countries and territories, 4673 institutions, and 20,161 authors. The growth rate of literature was relatively slow before 2015 and markedly accelerated after 2016. Among them, the United States occupies the absolute dominance in research in this field, publishing 37.25% of the papers, and the United States occupies 8 of the top 10 scientific institutions that publish papers. The University of Harvard has published the largest number of papers. Keyword analysis shows a total of 1125 keywords, and through reference literature and time clustering analysis shows that wound healing, sepsis, spine surgery, postoperative infection, nanocrystalline silver, beta lactamase are the current research hotspots. The escalating rate of literary expansion since 2016 suggests that this domain is garnering an increasingly significant amount of interest. Minimizing the risk of patient wound infection is crucial in reducing patients' discomfort and facilitating their prompt recovery. The literature analysis presented in this study serves as a valuable resource for comprehending the current state of the subject and identifying the current areas of focus.

Evaluation of the CARBA PAcE test, a colorimetric imipenem hydrolysis test for rapid detection of carbapenemase activity.

There is an urgent need for accurate and fast diagnostic tests to identify carbapenemase-producing bacteria. Here, we evaluated a colorimetric imipenem hydrolysis test, called the CARBA PAcE test, to detect carbapenemase-producing Gram-negative bacteria (GNB). We tested a collection of 270 GNB isolates with a characterized carbapenemase content. Our testing set included 205 carbapenemase-producing, carbapenemase-resistant Enterobacterales (CP CRE) with 40 Klebsiella pneumoniae carbapenemase (KPC), 49 New Delhi metallo beta lactamase (NDM), 49 OXA-48-like, 15 Verona integron-mediated metallo-β-lactamase (VIM), three IMP, 43 IMI, six isolates producing more than one carbapenemase, and 65 non-carbapenemase-producing Enterobacterales (20 ESBL producers, 35 non-carbapenemase-producing, carbapenem-resistant [non-CP CRE], and 10 carbapenem-susceptible Enterobacterales [non-CP, non-CSE, third-generation cephalosporin and carbapenem susceptible]). We compared the performances of the CARBA PAcE test, the qualitative colorimetric β-CARBA test, and the modified CarbaNP test to a gold standard of carbapenemase gene detection by PCR. Specificities of all tests were high: 95.4% (62/65) for CARBA PAcE test, 98.5% (64/65) for β-CARBA test, and 100% (65/65) for the modified CarbaNP test. Sensitivity varied by carbapenemase: all three tests had a sensitivity of 100% for NDM, VIM, and IMP and 97.5% for KPC. Sensitivity to detect IMI was 0% for the CARBA PAcE and β-CARBA tests and 11.6% for the modified CarbaNP test. Sensitivity to detect OXA-48-like was 89.7% for the CARBA PAcE test, 87.7% for the β-CARBA test, and 14.2% for the modified CarbaNP test. Reading the results of the CARBA PAcE assay was difficult. The CARBA PAcE assay is highly sensitive for detecting NDM, VIM, IMP, and KPC, but slightly less sensitive for OXA-48-like. It does not detect IMI. It is highly specific, and its overall diagnostic accuracy is similar to that of β-CARBA. Its operational advantages are rapid turnaround time, ease of use, and long shelf life, but reading of results is subjective.IMPORTANCEWe evaluated the ability of the CARBA PAcE test to detect carbapenemases in 274 Gram-negative isolates with a known carbapenemase content. Specificity was high for all carbapenemases tested (96.9%). Sensitivity was high for KPC, NDM, VIM, and IMP (97.5-100%); but lower for OXA-48-like (89.7%). Activity of IMI could not be detected. Taken together, our results indicate that CARBA PAcE is a useful alternative in regions where NDM and KPC are predominant. The limitations of the test are difficulty in reading results and incompatibility with mSuperCARBA.

Extended-spectrum beta-laktamase (ESBL) enzyme producing bacteria isolated from rectal swabs of around animals in dairy farms

This study aims to identify bacterial contamination of Klebsiella pneumoniae and Escherichia coli producing Extended Spectrum Beta Lactamase (ESBL) isolated from rectal swabs of local animals on a dairy farm in Deyeng Village, Kediri, East Java. Interviews and observations were conducted with farmers to obtain the required risk factor data (cleanliness of drinking and eating places, drinking water sources, and administration of antibiotics to livestock). The number of samples tested in this study was 34 samples, including 12 chicken samples, 8 goat samples, 5 duck samples, 4 rabbit samples, 3 cat samples and 2 goose samples. Samples were isolated on MCA media + cefotaxime 1 mg/l and isolated again on MCA media without the addition of antibiotics to multiply pure bacterial colonies. The tests carried out to determine the presence of ESBL-producing bacteria are biochemical tests, namely the IMViC test (Indole, Methyl red, Voges-Proskauer, Citrate Utilization), TSIA (Triple Sugar Iron Agar) test, gram staining, and the Double Disk Standard Method test using β-lactam disc antibiotics, namely cefotaxime 30μg, ceftazidime 30μg, and amoxycilline-clavulanate acid 30μg. The results of this research were that 6 samples or 17.6% of ESBL-producing bacteria were identified from poultry groups (chickens, ducks and geese) from dairy farms in Deyeng Village, Kediri Regency, East Java.

Assessment of community-acquired urinary tract infections treatment in the emergency department: a retrospective study.

Urinary tract infection (UTI) is one of the most common medical complaints in the emergency department (ED). The aim of this study was to assess the real indication of an initial broad-spectrum treatment administered in the ED for hospitalized patients with a diagnosis of community-acquired UTI (CAUTI). This is a monocentric observational retrospective study conducted in the ED of one of the largest tertiary care centers in Lebanon, on a two-year period, including adult patients admitted to the hospital for a CAUTI. The primary outcome was to evaluate the need of downgrading empirical antibiotherapy started in the ED. Secondary outcomes included a description of CAUTIs characteristics: prevalence and risk factors for (extended spectrum beta lactamases) ESBL-related infection, complicated and uncomplicated UTIs, empirical and targeted treatment, and finally the rate of adherence to local guidelines. The most isolated strains on urine cultures were gram negative bacilli (GNB) with 29.1% producing ESBL; 69.4% of patients received an ESBL-targeting empirical treatment in the ED, in agreement with local guidelines, 46% of which needed a downgrade. Amikacin adjunction was only indicated in 42.8% of the cases. Patients who received antibiotics in the last 6 months had a 2.36 times higher risk of developing an ESBL-related infection. This study showed a high adherence rate to local recommendations suggesting the use of empirical ESBL-targeting antibiotherapy even in uncomplicated UTIs. However, the frequent need of de-escalation highlights the importance of establishing an efficient multi-drug resistant (MDR) bacteria surveillance system in the community in order to elaborate a stewardship program with more solid local guidelines.

Degradation of extracellular antibiotic resistance genes using peracetic acid (PAA) and performic acid (PFA)

Antibiotic resistant bacteria (ARB) associated infections are identified as a major threat to human health in the 21st century. Wastewater contains antibiotic resistance determinants and they are discharged to aquatic environments with treated or untreated effluents. These antibiotic resistance determinants can be taken up by environmental bacteria via horizontal gene transfer (HGT) and they can become antibiotic resistant. Among antibiotic resistance determinants, extracellular DNA containing antibiotic resistance genes can be up taken by environmental bacteria via natural transformation. Therefore, we evaluated the suitability of low-cost disinfectants peracetic acid (PAA) and performic acid (PFA) on inactivating total and functional extracellular ARGs in ultrapure water and secondary wastewater effluent matrices using pUC19 as a model ARG. Performance of PAA and PFA in inactivating extracellular ARGs was compared with the performance of free chlorine disinfection. RT-qPCR results showed that inactivation of ampR gene in pUC19 plasmid suspended in ultrapure water and wastewater secondary effluent by free chlorine was higher compared to PAA and PFA. However, the reduction of functional pUC19 by PAA and PFA were comparable to free chlorine. Transformation frequency of pUC19 treated by PAA and PFA achieved the maximum possible reduction within a shorter time compared to free chlorine treatment, highlighting the possibility of having disinfection chambers with smaller footprints in wastewater treatment plants. These results suggest the suitability of PAA and PFA for inactivation of ARGs in aquatic samples as alternative disinfectants to free chlorine.

Functional metagenomics highlights varied infection states with dynamics of pathogens and antibiotic resistance in lower respiratory tract infections

BackgroundAntimicrobial resistance (AMR) amongst pathogenic bacterial species poses significant challenges in treating infections of the lower respiratory tract (LRT), leading to higher hospitalization and mortality rates. MethodsBronchoalveolar lavage fluid (BALF) from 84 clinically adjudicated LRTI patients were subjected to respiratory pathogen ID/AMR (RPIP) enrichment and sequencing followed by Explify and CZID seq data analysis to identify potential LRTI pathogens and associated AMR genes. Patients were categorized as LRTI-WP (with pneumonia) and LRTI-WoP (without pneumonia). FindingsmNGS achieved 100 % pathogen detection compared to 73 % through clinician-used BioFire panel. Predominant pathogens included Acinetobacter baumannii, Klebsiella pneumoniae along with detection of Aspergillus versicolor and Herpes simplex virus. Double and polymicrobial infections were captured, involving non-respiratory pathogens like Rothia mucilaginosa, Escherichia coli, and Moraxella osloensis. AMR detection highlighted macrolide (MPH; ERM) and Sulfonamide (SUL) rich resistome in 60 % of patients followed by extended spectrum beta lactamase (OXA) and tetracycline (TET). LRTI-WP showed high abundance of A. baumannii, majorly associated with MPH whereas K. pneumoniae with beta-lactams was comparable in both groups. Differences in clinical severity may stem from non-respiratory pathogens, newly recognized via mNGS. CZID seq pipeline validated and revealed additional microbes and AMR genes in the cohort. InterpretationThe prevalence of common pathogens like A. baumannii and K. pneumoniae along with the non-respiratory pathogens identified by RPIP-Explify and CZID seq provided an understanding to evaluate the LRTI. mNGS is crucial for precise pathogen and antibiotic resistance detection, vital for combating antibiotic resistance.

The antimicrobial resistance landscape of slaughterhouses in western Kenya: A microbiological case study

Slaughterhouses may be hotspots for the transmission of antimicrobial resistant (AMR) pathogens. To obtain information on the AMR landscape in Kenyan slaughterhouses, we collected swabs of the environment, animal carcasses, and workers. Bacterial isolates were identified in 101/193 (52.3 %) samples, and most showed resistance to streptomycin (68.7 %), ampicillin (48.7 %), and tetracycline (42.5 %). Multi drug resistance was exhibited by 35/80 isolates (43.8 %; 95 % CI: 33.2–54.9 %), while Extended Spectrum Beta Lactamase was expressed in 5/80 isolates (6.3 %; 95 % CI: 2.6–14.3 %). These findings illustrate the presence of resistant bacteria throughout the slaughterhouse environment, posing a risk to workers and meat consumers and highlighting the need for an integrated surveillance system along the food chain.

Beta-Lactamase production and antibiotic susceptibility screening of Staphylococus aureus isolated from ready to eat fruits sold in some parts of Offa Metropolis, Nigeria

The global menace of community-acquired antibiotic resistance of Beta Lactamase-producing Staphylococcus aureus has been traced to the increased consumption of Ready-to-eat Foods/Fruits. Samples each of ready-to-eat whole and sliced fruits (sliced pawpaw, apple, sliced watermelon, garden egg, cucumber, pear, guava, sliced coconut, berry and date fruit) were collected randomly from vendors in Offa, Kwara State, in Nigeria. Isolation and characterization of Staphylococcus aureus from the samples were done. The isolates were screened for Beta-Lactamase production and susceptibility to some antibiotics using standard microbiological techniques. A total of twenty-two (Twenty coagulase-positive and two coagulase-negative) Staphylococcus aureus was isolated. The total Staphylococal count was highest in sliced pawpaw (23.30 ± 2.75 × 10⁵ cfu/g) while the least was recorded in apple (3.0 ± 0.01 × 10⁵ cfu /g). Twenty (20) of the isolates were recorded to be Beta Lactamase producers. All the Beta Lactamase producers were 100 % resistant to Aztreoname, 80 % to Amoxicillin Clavulate, 45 and 35 % to Ceftazidine and Ceftriaxone. Thirty percent of the isolates were found to be susceptible to Ceftazidine only while 25 % were susceptible to Ceftriaxone only. The study concluded that increased incidence of Community-Acquired Multidrug-Resistant Staphylococcus aureus could be traceable to the consumption of unhygienic processed Ready-to-eat Fruits. The ripple effects of which could be dangerous to human health.

SHEDDING LIGHT ON GENETIC RELATIONSHIPS, PLASMID PROFILES AND ANTIBIOTIC RESISTANCE PATTERNS OF CLINICAL ESCHERICHIA COLI STRAINS: PULSED-FIELD GEL ELECTROPHORESIS PERSPECTIVE

In the present work, 47 Escherichia coli isolates collected from various clinical samples were elucidated with regard to genetic relationship, antibiotic resistance and plasmid profile. The genetic diversity of the isolates was defined by the pulsed field gel electrophoresis (PFGE) method. With a degree of similarity of 80%, the results from PFGE separated the E. coli strains into 39 different groups representing four subtypes. Antibiotic resistance patterns and extended spectrum of beta lactamase (ESBL) producing properties of the strains were determined by using a disk diffusion and double disc synergy method, respectively. According to the susceptibility test results, 36 distinct resistance profiles (resisto type) were observed among clinical strains. The strains were mostly resistant to ampicillin (100%) and this has been followed by cephalothin and ticarcillin/clavulanic acid with the ratio of 89.36%, cefuroxime with the ratio of 87.24%, tetracycline and cefotaxime with the ratio of 80.85%. It was observed that 24 of the strains (51.06%) were defined as ESBL positive. When E. coli strains were evaluated according to plasmid size, it was determined that 27 of 47 strains (57.44%) carried plasmids and the sizes of the determined plasmids were ranging between 77.1 kb and 1.6 kb. It was concluded that plasmids of E. coli strains are randomly distributed and no significant correlation was found between antibiotic resistance patterns and plasmids.

Extended spectrum and metalo beta lactamase producing gram negative bacterial pathogens from cockroaches collected at hospital, Southern Ethiopia

BackgroundCockroaches can pose a significant health risk in hospital environments because they may serve as reservoirs and vectors for nosocomial pathogens. Cockroaches harbor epidemiologically significant extended spectrum and metalo beta lactamase producing Gram negative bacterial pathogens, which complicate nosocomial infections.ObjectivesThe main aim of this study is to determine aetiology and phenotypic extended spectrum and metalo beta lactamase producing Gram negative bacteria pathogens from cockroaches collected in hospitals.MethodsA cross-sectional study was employed from February to May 2022 to determine the antibiotic resistance producing bacterial isolates from cockroaches by giving special emphasis to metalo beta lactamase and extended spectrum beta lactamase production from different wards of WSUCSH. Cockroaches were collected with hands wearing sterile gloves. External homogenate was prepared and incubated microbiologically by using different culture media and differentiated biochemically. Antimicrobial susceptibility testing was performed by disk diffusion method. ESBL production was conducted using double disc synergy method and double disk method was used to detect MBL enzyme detection. Descriptive statistics was used to determine prevalence and percentage.ResultOut of 245 cockroaches, 108 Gram negative bacteria were isolated. K. pneumoniae 29(26.9%) was the most predominant bacteria and Enetrobacter spp. 8(7.4%), was the least. All, K. pneumoniae, P. mirabilis, and Enterobacter isolates were pan-resistant to Ampicillin. P.aeruginosa and P.mirabilis antibiotics showed ≥ 80% resistant for amoxicillin/clavulanic acid antibiotics. Cefotaxime, ceftazidime, ceftriaxone and imipenem showed relative efficacy compared with other antibiotics. Out of 78 amoxicillin-clavulanic acid resistant isolates, 42(34.7%) were ESBL producers. ESBL production is more depicted by P. aeruginosa, A. baumannii, K. pneumoniae and E. coli. The overall prevalence of MBL production is 29(23.1%). K. pneumoniae P. aeruginosa, E.coli, A. baumannii, Enterobacter spp and K.oxytoca revealed MBL production.ConclusionThe overall prevalence of ESBL and MBL producing nosocomial agents from hospital cockroaches was 34.7% and 23.1% respectively. P.aeruginosa, A.baumannii, K.pneumoniae and E.coli showed pronounced ESBL production. All bacterial isolates except P. mirabilis and C. freundii showed MBL production. The needed to evaluate our antibiotic stewardship program and antibiotic resistance detection for treatment is mandatory. The impact of cockroach as a source of AMR should be sought.

Phytochemical Screening and Antimicrobial Activity of Methanol Extracts of Usteria guineensis and Sphaerocoryne gracilipes on Pathogens and ESBL-Producing Escherichia coli

Antibiotic resistance of microbial pathogens has become a threat to public health, with observed increase in outbreak of infections, therapeutic failure, morbidity and mortality. Pathogenic Escherichia coli and other extended spectrum beta lactamase (ESBL) producing bacteria causes serious health challenges due to antimicrobial resistance. This has caused an increasing research on medicinal plants as a source of alternative potential therapeutic agents. In this study, antimicrobial activity of Usteria guineensis (UG) and Sphaerocoryne gracilipes (SG) was investigated on standard organisms and clinical isolates of ESBL-producing E. coli. The leaves of Usteria guineensis and Sphaerocoryne gracilipes were extracted using methanol. Phytochemical analysis was carried out on the medicinal plants according to standard procedure. The clinical isolates of E. coli were screened for the production of ESBL using double disc synergy test, with E. coli ATCC 25922 as standard. Agar well diffusion method was used to determine antibacterial activity of the extracts at 100 and 25 mg/mL while Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were assessed using broth micro-dilution method. Statistical analysis was done using ANNOVA. The two plants contain cardiac glycoside, alkaloids and saponin and 11/15 (80%) of the E. coli isolates show the production of the ESBL. The extracts of the two plants showed antibacterial activity against ESBL E. coli with zone of inhibition ranging between 11 to 18 mm for Usteria guineensis and 12 to 15 mm for Sphaerocoryne gracilipes. The MIC of the extracts ranged between 0.78 to 50 mg/mL and MBC from 12.5 to &gt;50 mg/mL for the ESBL producers and the standard strains. Therefore, the two plants, especially Usteria guineensis have potentials to be developed as alternative therapeutic agents for the treatment of infections caused by ESBL-producing pathogens like Escherichia coli.

Integrating multi-wet laboratory diagnostics to study staphylococci in animals in Uganda

BackgroundSeveral diagnostic environments in Uganda lack real-time, robust and high-throughput technologies for comprehensive typing of microbes, which is a setback to infectious disease surveillance. This study combined various wet laboratory diagnostics to understand the epidemiology of pathogenic staphylococci isolated from animals in Uganda and the implications for global health security priorities.MethodsA retrospective study was conducted employing records and pathogenic staphylococci (from animals) archived at the Central Diagnostic Laboratory (CDL), Makerere University, Uganda, between January 2012 and December 2019. The bacteria were speciated by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and tested for virulence factors [beta lactamases, lecithinase, deoxyribonuclease (DNase), haemolysins] and resistance to ten antimicrobials of clinical and veterinary relevance. Tetracycline and methicillin resistance genes were also tested.ResultsThe prevalent diseases were mastitis in cattle and skin infections in dogs. Of the 111 staphylococci tested by MALDI-TOF MS, 79 (71.2%) were Staphylococcus aureus, 27 (24.3%) were Staphylococcus pseudintermedius and 5 (4.5%) were Staphylococcus schleiferi. All these strains expressed haemolysins. The prevalence of strains with lecithinase, penicillinase, cephalosporinase and DNase was 35.9% (14/39), 89.7% (35/39), 0.0% (0/39) and 87.2% (34/39), respectively. Staphylococci were primarily resistant to early penicillins (over 80%), tetracycline (57.7%), and chloramphenicol (46.2%). Minimal resistance was noted with cloxacillin (0.0%), ciprofloxacin (9.6%), and cefoxitin (3.8%). The prevalence of multidrug resistance (MDR) was 78.8% for general staphylococci, 82.2% for S. aureus, 73.1% for S. pseudintermedius, and 60.0% for S. schleiferi. Multidrug resistant staphylococci were significantly more prevalent in the cattle isolates than in the dog isolates (P < 0.05). The prevalence of methicillin-resistant staphylococci (MRS) tested by resistance to cefoxitin and mecA carriage was 3.8%. These four strains were all isolated from dog skin infections. The tetK gene was the most predominant (35.4%), followed by tetM (25.0%).ConclusionIn resource-constrained settings, the approach of integrated diagnostics promises sustainable disease surveillance and the addressing of current capacity gaps. The emergence of MRS (zoonotic bacteria) in companion animals creates a likelihood of reduced treatment options for related human infections, a threat to global health.

(Invited) Optimising CNT-FET Biosensor Design: Tuning Biomolecule Interfaces for Aptamer-Biomarker Sensing and Beta-Lactamase Detection

We will present different strategies to control the assembly of single walled carbon nanotube (SWCNT)-biomolecule interfaces towards the fabrication of bioelectronic devices, with a focus on the real-time biosensors with engineered aptamer and protein interfacing. In particular, we will report on the fabrication of nanoscale biosensing devices designed to present biorecognition moieties (aptamers and proteins) in defined orientations; this allowed us to control the local electrostatic surface presented within the Debye length, and thus modulate the conductance gating effect upon binding incoming targets, from biomarkers associated to stress and (neuro) trauma, to classes of enzyme relevant to antimicrobial resistance (beta-lactamases).Our efforts focused in particular on using beta-lactamase binding protein (BLIP2) as receptor due to its potential as a biosensor for the most common antibiotic degrading enzymes, the beta-lactamases (BLs). Attaching BLIP2 at single designed residues positions directly to SCNTs using genetically encoded phenyl azide photochemistry, our devices were able to successfully detect the two different BLs, TEM-1 and KPC-2. The changes in conductance closely matched the predicted electrostatic profile sampled by the CNTs on BL binding.These studies highlight the key role transducer-biomolecule interfaces play in biosensing devices, and the need to control and tune by design the electrostatic gating, for more effective and optimal CNT-FET biosensor construction.

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.

Epidemiological pattern and genomic insights into multidrug-resistant ST491 Acinetobacter baumannii BD20 isolated from an infected wound in Bangladesh: Concerning co-occurrence of three classes of beta lactamase genes

ObjectiveMultidrug-resistant (MDR) Acinetobacter baumannii is a major issue within healthcare facilities in Bangladesh due to its frequent association with hospital-acquired infections. In this study we report on a carbapenem-resistant draft genome sequence of an A. baumannii BD20 sample isolated from an infected wound in Bangladesh. MethodsA. baumannii BD20 was isolated from an infected burn wound. Whole-genome sequencing was carried out and annotated using PGAP and Prokka. Sequence type, antimicrobial resistance genes, virulence factor genes, and metal resistance genes were investigated. Core genome multilocus sequence typing–based phylogenomic analysis between A. baumannii BD20 and 213 A. baumannii strains retrieved from the NCBI GenBank database was performed using the BacWGSTdb 2.0 server. ResultsA. baumannii BD20 (MLST 491) was resistant to all the antibiotics tested, except for colistin and polymyxin B. Along with many other antibiotic resistance genes, the isolate harbored three classes of beta lactamase–producing genes: blaGES-11 (class A), blaOXA-69 (class D), blaADC-10 (class C), and blaADC-11 (class C). Additionally, the strain carried several virulence genes and metal resistance determinants, which may contribute to its increased virulence. Core genome MLST–based phylogenomic analysis revealed that A. baumannii BD20 was closely related to another ST491 strain isolated from Singapore. ConclusionsThe findings of this study underscore the growing challenge of MDR A. baumannii, emphasizing the need for vigilant surveillance and infection-control measures in healthcare settings in order to address these emerging threats effectively.

In silico Molecular Docking of Cyclic Peptides against TEM-1 Beta-Lactamases for Effective Antimicrobial Drug Development

Targeting the class A Beta lactamases Omega loop is an ideal way to combat drug resistance because of its significant role in the catalytic activity and deacylation process inhibition. Therefore, the molecular docking approach with computerized peptide-based in silico screening has been applied for the identification of inhibitors of TEM-type βLs. Among the subjected 105 peptides, Chrombacin (-47.8 KJ/mol), Gassericin A (-35.7 KJ/mol), Duramycin (-34.1 KJ/mol), Brevinin-1DYa (-34.0 KJ/mol), Amoebapore A (-31.2 KJ/mol), Mundticin ATO6 (-29.0 KJ/mol), Lactocyclicin Q (-26.3 KJ/mol), Cinnamycin (-25.9 KJ/mol showed highest binding energy. Among the peptides that showed the highest docking score Elafin, Cinnamycin, Duramycin interacted with Lys 73 of the α domain of catalytic residues of TEM-1 Beta lactamases, whereas Taromycin A, Gassericin A interacted with Lys 234 of the β domain, depicting a strong inhibition and also exhibited desirable physicochemical properties. Hence further in vitro examination of these cyclic peptides against the resistant strains is warranted to help design further novel inhibitors based on their scaffolds and also for the development of an effective drug combination regime.

Efficacy of Nitrofurantoin and Fosfomycin against Extended Spectrum Beta Lactamase Producing Uropathogens in the Era of Antibiotic Resistance: A Cross-sectional Study

Background: Urinary Tract Infection (UTI) is one of the most common bacterial infections that require medical care. It accounts for 25% of all infections. Limited number of antibiotics are available for the treatment of UTI due to increased resistance among uropathogens. Aim of the study is to determine the causative agents of UTI and to evaluate the action of nitrofurantoin and fosfomycin against Enterobacteriaceae in ESBL (Extended spectrum beta-lactamase) producing strains. Material and Methods: It is a retrospective study carried out in the department of Microbiology, MAMC, Agroha. Data related to urine culture and antibiotic susceptibility pattern from January 2023 to December 2023 was taken from the records and analysed. Results: Out of 1648 urine samples processed, 569 showed significant bacterial growth. Escherichia coli (45.3%) was the most common isolate followed by Klebsiella pneumoniae (20.5%), Enterococcus (17.2%), Staphylococcus aureus (5%). Among the gram negative bacilli, 40% were ESBL producers. These ESBL producing strains were 99% sensitive to Fosfomycin and 75% sensitive to Nitrofurantoin. Conclusion: The study revealed that Nitrofurantoin and Fosfomycin are very effective oral drugs for empirical treatment against gram negative uropathogens causing UTI, especially multi drug resistant strains.