Frequency, serotyping, antibiogram, and seasonality of Salmonella isolated from red meat markets.

Bacterial pathogenic strains are as adaptable as Salmonella strains and cause diverse intestinal and extraintestinal diseases in humans and other mammals worldwide. Red meat and its products are important hosts for many zoonotic diseases. This work was designed to investigate the frequency, serotypes, and antimicrobial resistance profile of isolated Salmonella spp. in red meat (cattle, sheep, and goats) sold in Dhamar Governorate, Yemen. A total of 250 red meat samples were collected from the retail seller market between July and December 2022. All samples were transported immediately to the laboratory, subcultured on selective enrichment agar, and identified by serotyping and antimicrobial susceptibility tests via disk diffusion methods. The results indicated 26 positive samples of Salmonella out of the 250 samples (10.4%). Notably, isolates belong to ten various serotypes: S. Typhimurium 19.2%, S. Anatum 15.4%, S. Newport 11.5%, S. Enteritidis 11.5%, S. Muenchen 11.5%, S. Infantis 7.7%, S. Montevideo 7.7%, S. Dublin 7.7%, S. Senftenberg 3.9%, and S. Arizona 3.9%. The antibiotic resistance profile revealed that 57.5%, 53.9%, and 53.9% of isolates are resistant to erythromycin, tetracycline, and norfloxacin, respectively. This resistance among Salmonella spp. suggests a significant threat to health, which will in turn require an active safety measure and response. On the other hand, the seasonal variations "August and July" were found to be associated with an increased frequency of Salmonella isolation.

Phenotypic and genotypic determination of resistance to common disinfectants among strains of Acinetobacter baumannii producing and non-producing biofilm isolated from Iran.

BACKGROUND: Nosocomial infections are a global problem in hospitals all around the world. It is considered a major health problem, especially in developing countries. The increase in the patient's stay in hospitals has increased the mortality rate, and consequently, the costs drastically increase. The main purpose of using disinfectants in the hospital environment is to reduce the risk of nosocomial infections. Ethylene diamine tetra acetic acid (EDTA) causes lysis and increases susceptibility to antimicrobial agents in the planktonic form of bacteria. This substance affects the permeability of the outer membrane of bacteria. It also prevents the formation of biofilms by bacteria. MATERIALS AND METHODS: In the current study, 120 isolates of Acinetobacter baumannii (A. baumannii) were confirmed by phenotypic and genotypic methods. Antibiogram was performed and then the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of isolates against 5% sodium hypochlorite, ethanol %70, sayasept-HP 2%, chlorhexidine 2%, dettol 4/8% were evaluated. In addition, the disinfectant effect was re-evaluated with the mixture of EDTA solution. All isolates were examined for biofilm presence by crystal violet staining method in triplicates and repeated three times for each strain. Also for all isolates detection of efflux pump genes (Qac-E, qacE-Δ1, SUG-E) by PCR technique was done. RESULTS: Antibiogram results of A. baumannii showed that 6.7% were Multi-drug-resistant (MDR), and 89.2% were Extensively drug-resistant (XDR) isolates. The highest effect of disinfectants was related to 5% sodium hypochlorite, and the least effect was 70% ethanol. EDTA increases the efficacy of selected disinfectants significantly. The highest prevalence of the efflux pump genes was related to SUG-E (95%) and Qac-E (91.7%), and, the qacE-Δ1 gene with 12.5%. The biofilm production rate was 91.3% among all isolates. CONCLUSION: The best and safest way to disinfect hospital floors and surfaces is to choose the right disinfectants, and learn how to use them properly. In this study, a mixture of disinfectants and EDTA had a significant effect on bactericidal activity. it was found that improper use of disinfectants, especially the use of sub-inhibitory dilutions, increases the resistance of bacteria to disinfectants.

Assessment of Antibiotic Resistance in Pediatric Infections: A Romanian Case Study on Pathogen Prevalence and Effective Treatments.

Antibiotic misuse in Romania has exacerbated the issue of antibiotic resistance, as patients often use antibiotics without proper medical consultation. This study aimed to assess the resistance of prevalent bacteria to different antibiotics. In this observational study conducted over six months, we analyzed 31 pediatric patients aged from 12 days to 13 years using the disk diffusion method. We identified 31 bacterial isolates, including 8 Gram-negative and 8 Gram-positive strains, with the most common being Pseudomonas aeruginosa, Escherichia coli, Streptococcus pneumoniae, methicillin-resistant Staphylococcus aureus, Streptococcus species, and Elizabethkingia meningoseptica. Our findings revealed that the most effective antibiotics were linezolid, ertapenem, and teicoplanin. In contrast, nearly all tested bacteria exhibited resistance to penicillin, followed by oxacillin and ampicillin. Resistance to cephalosporins varied with generation, showing higher resistance to lower-generation cephalosporins. The study highlights significant antibiotic resistance among common bacterial pathogens in Romanian pediatric patients, emphasizing the urgent need for controlled antibiotic use and alternative treatment strategies to combat this growing issue. Effective antibiotics such as linezolid and ertapenem offer potential solutions, whereas reliance on penicillin and lower-generation cephalosporins is increasingly futile.

Establishment of an Antimicrobial Stewardship Program to Spare the Use of Oral Fluoroquinolones for Acute Uncomplicated Cystitis in Outpatients.

The increase in fluoroquinolone (FQ)-resistant Escherichia coli (EC) is a serious global problem. In addition, much of acute uncomplicated cystitis (AUC) cases are caused by EC. FQs have been selected for the treatment of cystitis in outpatients, and there is concern about treatment failure. It is therefore necessary to select appropriate antimicrobials to spare FQs. However, there are few reported effective antimicrobial stewardship programs (ASPs) for outpatients. We aimed to establish the effective ASP for outpatients diagnosed with AUC caused by EC, to spare the use of FQs, and to explore optimal oral antimicrobials for AUC. The study subjects were outpatients treated for AUC caused by extended-spectrum ß-lactamase-non-producing EC (non-ESBL-EC). Based on the antibiogram results, we recommended cefaclor (CCL) as the initial treatment for AUC, and educated clinical pharmacists who also worked together to advocate for CCL or cephalexin (CEX) prescriptions. FQ usages decreased, and cephalosporin (Ceph) prescriptions increased in all medical departments. The Ceph group (n = 114; CCL = 60, CEX = 54) in the non-FQ group had fewer treatment failures than the FQ group (n = 86) (12.3% vs. 31.4%). Cephs, including CCL and CEX, were effective treatments for AUC caused by non-ESBL-EC. Antimicrobial selection based on antibiogram results and the practice of an ASP in collaboration with clinical pharmacists were useful for optimizing antimicrobial therapy in outpatients.

PCR-based RFLP and ERIC-PCR patterns of Helicobacter pylori strains linked to multidrug resistance in Egypt.

H. pylori infects approximately 50% of the world's population that causes chronic gastritis, and may lead to peptic ulcer disease (PUD). H. pylori-induced chronic infections are associated with gastric adenocarcinoma and low-grade gastric lymphoma. In Egypt, H. pylori strains are widespread and became resistant to antimicrobial agents, thus advanced typing methods are needed to differentiate infectious strains that are resistant to antibiotics, and therefore earlier prognosis and infection control. The main objectives were (i) to determine susceptibility of infectious H. pylori strains to some antimicrobial agents that are currently used in eradication therapy in Egypt; (ii) to identify diverse strains commonly detected in the gastrointestinal (GIT) endoscopy units in Egypt through phenotypic and genotypic analyses. In this observational study we isolated 167 isolates from 232 gastric biopsies (antrum and corpus) of patients who were admitted to the upper GIT endoscopy units in five governmental Egyptian hospitals. Antimicrobial susceptibility patterns were investigated using Kirby Bauer disc diffusion and agar dilution Minimum Inhibitory Concentrations (MICs) methods. Phenotypic characterization was based on biotyping and antibiogram typing techniques. Genotypic characterization was carried out using PCR-based Restriction Fragment Length Polymorphism (RFLP) and Enterobacterial Repetitive Intergenic Consensus (ERIC)-PCR analyses. H. pylori isolates were highly resistant to diverse antimicrobial agents including Metronidazole, Fluoroquinolones, Macrolides, Amoxycillin, Tetracycline and Gentamicin. Two factors contributed to the increased resistance of H. pylori to the conventional therapy seen in Egypt: (i) Metronidazole and Amoxycillin are inexpensive and available drugs being abused by patients; (ii) the regional prescribing practice of Macrolids commonly used to treat upper respiratory and urinary tract infections. Five different biotypes were identified depending on the ability of the isolates to synthesize different enzymes. Nine antibiogram types were identified. PCR-RFLP analysis revealed fifteen different fingerprints while ERIC-PCR revealed 22 fingerprints. Biotyping alone or in combination with antibiogram typing are highly useful molecular tools in the prognosis of strain relatedness. PCR-RFLP and ERIC-PCR acquired good discriminatory power for identifying H. pylori infectious sub-types.

Acute cholangitis: a state-of-the-art review.

Acute cholangitis is a potentially life-threatening bacterial infection of the intra and/or extrahepatic bile ducts. It remains the second and third cause of community-acquired and hospital-acquired bacteremia, respectively, and is associated with mortality rates of up to 15%, despite advances in broad-spectrum antimicrobial therapy and improved access to emergency biliary tract decompression procedures. Even though not much has changed in recent years in terms of diagnosis or treatment, new data have emerged regarding multidrug-resistant bacteria that serve as etiologic agents of cholangitis. Moreover, different approaches in antibiotic regimes depending on severity grading and bile sample cultures as well as novel minimally invasive endoscopic procedures that can help when consecrated treatments such as endoscopic retrograde cholangiopancreatography (ERCP) fail, cannot be performed, or are unavailable have been proposed. This state-of-the-art review aims to offer a complete and updated assessment of the epidemiology, novel diagnostic and therapeutic methods, complications, and prognostic variables of acute cholangitis. The authors will review the prognostic implications of unusual complications, the relevance of regular bile samples and antibiograms, and their new role in guiding antibiotic therapy and limiting antibiotic resistance to present an organized and comprehensive approach to the care of acute cholangitis.

Exploring the Antimicrobial Resistance Profile of Salmonella typhi and Its Clinical Burden.

Background: Typhoid fever caused by Salmonella enterica serovar Typhi (S. typhi) continues to pose a significant risk to public health in developing countries, including Pakistan. This study investigated the epidemiological factors linked to suspected and confirmed S. typhi infections in Peshawar's hospital population. Methodology: A total of 5735 blood samples of patients with suspected enteric fever were collected from September 2022 to November 2023. S. typhi infection was confirmed using microbiological culture of blood samples, biochemical-based tests, and DNA-sequencing methods. Drug sensitivity testing on cultures was conducted as per the CLSI guidelines. Chi-square tests were used to analyze the clinical and epidemiologic characteristics of 5735 samples stratified by S. typhi infection status, and risk factors were assessed by applying logistic regression models to estimate odds ratios (ORs). Results: The number of confirmed typhoid fever cases in this hospital-based study population was 691 (/5735, 12.0%), more prevalent in males (447/3235 13.8%) and children (0-11 years) (429/2747, 15.6%). Compared to children, the risk of S. typhi infection was lower in adolescence (adjusted OR = 0.52; 95% CI: 0.42-0.66), adulthood (19-59 years; aOR = 0.30; 95% CI: 0.25-0.38), and older adulthood (aOR = 0.08; 95% CI: 0.04-0.18) (p < 0.001). Compared to males, the risk of S. typhi infection was lower in females (aOR = 0.67; 95% CI = 0.56-0.80; p = 0.002). Living in a rural residence (compared to urban) was associated with a higher risk of infection (aOR = 1.38; 95% CI: 1.16-1.63; p = 0.001), while access to a groundwater source (compared to municipal water supply) led to a lower risk (aOR = 0.56; 95% CI: 0.43-0.73; p = 0.002). Vaccination demonstrated a robust protective effect (aOR = 0.069; 95% CI = 0.04-0.11, p = 0.002). For those with typhoid infections, clinical biomarker analysis revealed the presence of leucopenia (65/691, 9.4%), thrombocytopenia (130/691, 18.8%), and elevated alanine aminotransferase (ALT) (402/691, 58.2%) and C-reactive protein (CRP) (690/691, 99.9%) levels. Worryingly, among the positive S. typhi isolates, there was a high prevalence of drug resistance (653/691), including multidrug-resistant (MDR 82/691, 11.9%) and extensively drug-resistant types (XDR, 571/691, 82.6%). Conclusions: This study highlights the importance of age, sex, locality, water source, and vaccination status in shaping the epidemiological landscape of S. typhi in the Peshawar district. It implies that expanding vaccination coverage to the broader population of Khyber Pakhtunkhwa province, particularly in the district of Peshawar, would be beneficial.

Evaluation of the quickmic system in the rapid diagnosis of Gram-negative bacilli bacteremia.

Rapid microbiological diagnosis of the antibiotic susceptibility of Gram-negative bacilli is a priority in clinical microbiology, especially in cases of bacteremia. The rapid advancement of antimicrobial resistance proposes a challenge for empirical antibiotic therapy and shows the need for fast antibiotic susceptibility diagnostics to guide treatments. The QuickMIC System (Gradientech AB, Uppsala, Sweden) is a recently developed rapid diagnostic tool for antibiotic susceptibility testing. Our study evaluates a rapid phenotypic system (QuickMIC) that provides information on the susceptibility of 12 antibiotics against Escherichia coli, Klebsiella spp., Pseudomonas aeruginosa, Acinetobacter baumannii, Enterobacter cloacae, Proteus spp., Citrobacter spp., and Serratia marcescens. A total of 816 antibiotic/microorganism combinations were tested, resulting in eight discrepancies. The concordance between the antibiotics offered by QuickMIC and reference methods (MicroScan WalkAway plus system, Beckman Coulter; Etest (BioMerieux microdilution system (Bruker); Real-time PCR (GeneXpert, Cepheid); and immunochromatography (Biotech) was 99.02%. Time elapsed to obtain a valid minimal inhibitory concentration (MIC) was between 2 and 4 h. The QuickMIC system allows for the early adjustment of antibiotic treatment in these infections. Given the existing limitations of currently available rapid methods, its clinical utility is particularly relevant in the management of P. aeruginosa infections and AmpC-producing Enterobacterales. The use of rapid methods can help diversify antibiotic use and reduce carbapenem consumption. IMPORTANCE: The rapid diagnosis of antibiotic sensitivity in Gram-negative bacilli is of paramount importance in clinical microbiology, particularly in cases of bacteremia. The escalating challenge of antimicrobial resistance underscores the need for expeditious antibiotic susceptibility diagnostics to guide empirical antibiotic therapy effectively. In light of this, we present our study that evaluates the QuickMIC System, a recently developed rapid diagnostic antibiogram. QuickMIC System, offers a novel approach to phenotypic testing, providing information on the activity of 12 antibiotics against key pathogens, including Escherichia coli, Klebsiella spp., Pseudomonas aeruginosa, Acinetobacter baumannii, Enterobacter cloacae, Proteus spp., Citrobacter spp., and Serratia marcescens. Our investigation involved testing a total of 816 antibiotic/microorganism combinations. The study demonstrated an impressive 99.02% concordance between the QuickMIC System and the reference methods, with only eight discrepancies observed. The time to actionable minimum inhibitory concentration (MIC) ranged between 2 and 4 h, highlighting the system's efficiency in providing rapid results.

A Bayesian Model Based on Local Phenotypic Resistance Data to Inform Empiric Antibiotic Escalation Decisions.

INTRODUCTION: Clinicians commonly escalate empiric antibiotic therapy due to poor clinical progress without microbiology guidance. When escalating, they should take account of how resistance to an initial antibiotic affects the probability of resistance to subsequent options. The term "escalation antibiogram" (EA) has been coined to describe this concept. One difficulty when applying the EA concept to clinical practice is understanding the uncertainty in results and how this changes for specific patient subgroups. METHODS: A Bayesian model was developed to estimate antibiotic resistance rates in Gram-negative bloodstream infections based on phenotypic resistance data. The model generates a series of "credible" curves to fit the resistance data, each with the same probability of representing the true rate given the inherent uncertainty. To avoid overfitting, an integrated penalisation term adaptively smooths the curves given the level of evidence. RESULTS: Rates of resistance to empiric first-choice and potential escalation antibiotics were calculated for the whole hospitalised population based on 10,486 individual bloodstream infections, and for a range of specific patient groups, including ICU (intensive care unit), haematolo-oncology, and paediatric patients. The model generated an expected value (posterior mean) with 95% credible interval to illustrate uncertainty, based on the size of the patient subgroup. For example, the posterior means of piperacillin/tazobactam resistance rates in Gram-negative bloodstream infection are different between patients on ICU and the general hospital population: 27.3% (95% CI 18.1-37.2 vs. 13.4% 95% CI 11.0-16.1) respectively. The model can also estimate the probability of inferiority between two antibiotics for a specific patient population. Differences in optimal escalation antibiotic options between specific patient groups were noted. CONCLUSIONS: EA analysis informed by our Bayesian model is a useful tool to support empiric antibiotic switches, providing an estimate of local resistance rates, and a comparison of antibiotic options with a measure of the uncertainty in the data. We demonstrate that EAs calculated for the whole hospital population cannot be assumed to apply to specific patient group.

Evaluating the Sputum Bacteriological Profile of Lower Respiratory Tract Infections With Bartlett Score Analysis in a Tertiary Care Hospital in Southern Karnataka.

INTRODUCTION: Lower respiratory tract infections (LRTIs) are one of the most commonly encountered infections with significant mortality and morbidity. Sputum is the most frequently obtained sample for LRTI diagnosis. However, sputum samples carry the risk of being non-representative due to the risk of contamination with oral colonizers. To overcome the dilemma with respect to representative sampling, the use of a scoring system such as the Bartlett scoring system is emphasized. This study probes the bacterial profile of sputum samples among patients presenting with LRTIs and their antibiotic susceptibility profile in relation to the Bartlett scoring system. METHODOLOGY: Retrospective data for a period of three years, comprising 4960 sputum samples from patients presenting with LRTI, were collected to study the bacterial profile and antibiogram in comparison with the sputum quality analyzed by the Bartlett scoring system. RESULTS: Out of the 4960 sputum samples analyzed from patients with LRTI, 31.18% yielded the growth of bacterial pathogens, and 98.64% of the sputum samples yielding pathogenic growth had a significant Bartlett score. CONCLUSION: Sputum samples are non-invasive representative samples of lower airway infective pathologies. Sputum quality assessment by Bartlett scoring serves as a proxy marker to rule out respiratory colonization and aid culture-based diagnosis.

Comparison of Different Methods for Assaying the In Vitro Activity of Cefiderocol against Carbapenem-Resistant Pseudomonas aeruginosa Strains: Influence of Bacterial Inoculum.

Carbapenem-resistant Pseudomonas aeruginosa infections represent a critical public health concern, highlighting the need for the development of effective antibiotics. Cefiderocol demonstrated potent in vitro activity against Pseudomonas aeruginosa, particularly in strains that are resistant to other drugs. However, concerns regarding the emergence of drug-resistant strains persist. This study, conducted with 109 carbapenem-resistant Pseudomonas aeruginosa strains from the Spanish Hospital (Dr. Balmis, Alicante). The study evaluated susceptibility to cefiderocol in comparison to alternative antibiotics and including their susceptibility to bacterial inoculum, while assessing various testing methods. Our findings revealed high susceptibility to cefiderocol against carbapenem-resistant strains, with only 2 of 109 strains exhibiting resistance. Comparative analysis demonstrated superiority of cefiderocol towards alternative antibiotics. Both the E-test and disk-diffusion methods showed 100% concordance with the microdilution method in classifying strains as susceptible or resistant. However, 4.6% (5/109) of disc zone diameters fell within the technical uncertainty zone, so the E-test technique was found to be more useful in routine clinical practice. Additionally, escalating bacterial inoculum correlated with decreases in vitro activity, so this parameter should be adjusted very carefully in in vivo studies. This study underscores cefiderocol's potential as a therapeutic option for carbapenem-resistant Pseudomonas aeruginosa infections. However, the emergence of drug-resistant strains emphasizes the critical need for a wise use of antibiotics and a continuous monitoring of resistance to antibiotics. Based on our in vitro data, further investigation concerning the impact of bacterial inoculum on drug efficacy is warranted in order to detect resistance mechanisms and optimize treatment strategies, thereby mitigating the risk of resistance.

Rapid and Simple Morphological Assay for Determination of Susceptibility/Resistance to Combined Ciprofloxacin and Ampicillin, Independently, in Escherichia coli.

Current antibiograms cannot discern the particular effect of a specific antibiotic when the bacteria are incubated with a mixture of antibiotics. To prove that this task is achievable, Escherichia coli strains were treated with ciprofloxacin for 45 min, immobilized on a slide and stained with SYBR Gold. In susceptible strains, the nucleoid relative surface started to decrease near the MIC, being progressively condensed as the dose increased. The shrinkage level correlated with the DNA fragmentation degree. Ciprofloxacin-resistant bacilli showed no change. Additionally, E. coli strains were incubated with ampicillin for 45 min and processed similarly. The ampicillin-susceptible strain revealed intercellular DNA fragments that increased with dose, unlike the resistant strain. Co-incubation with both antibiotics revealed that ampicillin did not modify the nucleoid condensation effect of ciprofloxacin, whereas the quinolone partially decreased the background of DNA fragments induced by ampicillin. Sixty clinical isolates, with different combinations of susceptibility-resistance to each antibiotic, were co-incubated with the EUCAST breakpoints of susceptibility of ciprofloxacin and ampicillin. The morphological assay correctly categorized all the strains for each antibiotic in 60 min, demonstrating the feasible independent evaluation of a mixture of quinolone and beta-lactam. The rapid phenotypic assay may shorten the incubation times and necessary microbial mass currently required for evaluation.

Antibiotyping, RAPD- and ERIC-PCR fingerprinting of Klebsiella pneumoniae clinical isolates at a tertiary reference hospital in Denpasar, Bali, Indonesia.

Background and Objectives: Klebsiella pneumoniae is a healthcare-associated infections agent and could be an extended spectrum ß-lactamase (ESBL) producer. Understanding the transmission of this bacterium in a hospital setting needs accurate typing methods. An antibiogram is used to detect the resistance pattern of the isolates. Random Amplified Polymorphic DNA (RAPD) and Enterobacterial Repetitive Intergenic Consensus (ERIC)-PCR are rapid, technically simple, and easy-to-interpret DNA typing methods. This study aimed to evaluate the use of antibiotyping, RAPD-, and ERIC-PCR to investigate the heterogeneity of K. pneumoniae isolated from clinical specimens. Materials and Methods: The antibiograms of 46 K. pneumoniae clinical isolates were determined by Vitek® 2 Compact. All isolates underwent RAPD-PCR using AP4 primer and ERIC-PCR using ERIC-2 primer. The dendrogram was generated using the GelJ software and analyzed to determine its similarity. The analysis of antibiogram and the molecular typing diversity index was calculated using the formula of the Simpson's diversity index. Results: About 71.7% of the isolates were ESBL-producers, and more than 80% of isolates were susceptible to amikacin, ertapenem, and meropenem. The antibiotyping produced 32 diverse types with DI = 0.964. In addition, the RAPD-PCR produced 47 different types with DI = 1, while ERIC-PCR was 46 (DI=0.999). Conclusion: Antibiotyping, RAPD- and ERIC-PCR showed powerful discrimination power among the isolates, supported the diversity of K. pneumoniae isolates in current study. These combination could be promising tools for clonal relationship determination, including in tracking the transmission of the outbreak's agent in hospital setting.

Coagulase-negative staphylococci from bovine milk: Antibiogram profiles and virulent gene detection.

BACKGROUND: Coagulase-negative Staphylococcus species are an emerging cause of intramammary infection, posing a significant economic and public health threat. The aim of this study was to assess the occurrence of coagulase-negative Staphylococcus species in bovine milk and dairy farms in Northwestern Ethiopia and to provide information about their antibiotic susceptibility and virulence gene profiles. METHODS: The cross-sectional study was conducted from February to August 2022. Coagulase-negative Staphylococcus species were isolated from 290 milk samples. Species isolation and identification were performed by plate culturing and biochemical tests and the antimicrobial susceptibility pattern of each isolate was determined by the Kirby-Bauer disc diffusion test. The single-plex PCR was used to detect the presence of virulent genes. The STATA software version 16 was used for data analysis. The prevalence, proportion of antimicrobial resistance and the number of virulent genes detected from coagulase-negative Staphylococcus species were analyzed using descriptive statistics. RESULTS: Coagulase-negative Staphylococcus species were isolated in 28.6%, (95% CI: 23.5-34.2) of the samples. Of these, the S. epidermidis, S. sciuri, S. warneri, S. haemolyticus, S. simulans, S. chromogens, S. cohnii, and S. captis species were isolated at the rates of 11, 5.2, 3.4, 3.1, 3.1, 1, 1, and 0.7% respectively. All the isolates showed a high percentage (100%) of resistance to Amoxicillin, Ampicillin, and Cefotetan and 37.5% of resistance to Oxacillin. The majority (54.2%) of coagulase-negative isolates also showed multidrug resistance. Coagulase-negative Staphylococcus species carried the icaD, pvl, mecA, hlb, sec, and hla virulent genes at the rates of 26.5%, 22.1%, 21.7%, 9.6%, 9.6% and 8.4% respectively. CONCLUSION: The present study revealed that the majority of the isolates (54.2%) were found multidrug-resistant and carriage of one or more virulent and enterotoxin genes responsible for intramammary and food poisoning infections. Thus, urgent disease control and prevention measures are warranted to reduce the deleterious impact of coagulase-negative species. To the best of our knowledge, this is the first study in Ethiopia to detect coagulase-negative Staphylococcus species with their associated virulent and food poisoning genes from bovine milk.

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

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

Phytochemical Screening and Antibacterial Activity of Commercially Available Essential Oils Combinations with Conventional Antibiotics against Gram-Positive and Gram-Negative Bacteria.

The present study aims to evaluate the antibacterial activity of five commercially available essential oils (EOs), Lavender (LEO), Clove (CEO), Oregano (OEO), Eucalyptus (EEO), and Peppermint (PEO), against the most-known MDR Gram-positive and Gram-negative bacteria-Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 25922), and Pseudomonas aeruginosa (ATCC 27853)-alone and in various combinations. Gas Chromatography-Mass Spectrometry (GC-MS) analysis established their complex compositions. Then, their antibacterial activity-expressed as the inhibition zone diameter (IZD) value (mm)-was investigated in vitro by the diffusimetric antibiogram method, using sterile cellulose discs with Ø 6 mm impregnated with 10 µL of sample and sterile borosilicate glass cylinders loaded with 100 µL; the minimum inhibitory concentration (MIC) value (µg/mL) for each EO was calculated from the IZD values (mm) measured after 24 h. The following EO combinations were evaluated: OEO+CEO, CEO+EEO, CEO+PEO, LEO+EEO, and EEO+PEO. Then, the influence of each dual combination on the activity of three conventional antibacterial drugs-Neomycin (NEO), Tetracycline (TET), and Bacitracin (BAC)-was investigated. The most active EOs against S. aureus and E. coli were LEO and OEO (IZD = 40 mm). They were followed by CEO and EEO (IZD = 20-27 mm); PEO exhibited the lowest antibacterial activity (IZD = 15-20 mm). EEO alone showed the highest inhibitory activity on P. aeruginosa (IZD = 25-35 mm). It was followed by CEO, LEO, and EEO (IZD = 7-11 mm), while PEO proved no antibacterial action against it (IZD = 0 mm). Only one synergic action was recorded (OEO+CEO against P. aeruginosa); EEO+PEO revealed partial synergism against S. aureus and CEO+PEO showed additive behavior against E. coli. Two triple associations with TET showed partial synergism against E. coli, and the other two (with NEO and TET) evidenced the same behavior against S. aureus; all contained EEO+PEO or CEO+PEO. Most combinations reported indifference. However, numerous cases involved antagonism between the constituents included in the double and triple combinations, and the EOs with the strongest antibacterial activities belonged to the highest antagonistic combinations. A consistent statistical analysis supported our results, showing that the EOs with moderate antibacterial activities could generate combinations with higher inhibitory effects based on synergistic or additive interactions.

Detection and antibiogram profile of diarrheagenic Escherichia coli isolated from two abattoir settings in northwest Ethiopia: a one health perspective.

BACKGROUND: Diarrheagenic Escherichia coli (E. coli) is a zoonotic pathogen that contaminates abattoir workers, slaughter environments, slaughter equipment, and carcasses during abattoir processing. Infection with E. coli is associated with the consumption of contaminated food and water, and it is a potential threat to the health and welfare of both humans and animals. Hence, this study aimed to detect diarrheagenic E. coli and assess its antibiogram profile in two abattoir settings, in one health lens. METHODS: A cross-sectional study in one health approach was conducted from December 2020 to June 2021. A total of 384 samples from abattoir workers' hands, carcasses, knives, cattle feces, abattoir water and effluents were collected. Bacterial culture and biochemical tests were conducted to isolate E. coli, while conventional polymerase chain reaction was performed to identify virulence genes. The antibiogram of diarrheagenic E. coli was tested against nine antimicrobials using the Kirby Bauer disk diffusion method. RESULTS: A total of 115 (29.95%) E. coli were isolated from the 384 samples, and from these isolates, about 17 (14.8%) were confirmed to be diarrheagenic E. coli (DEC). Among the DEC pathotypes, nine (52.94%), five (29.4%), and three (17.65%) were Shiga toxin-producing, enterohemorrhagic, and enterotoxigenic E. coli, respectively. While 14 (82.35%) DEC isolates harbored the stx2 gene, five (29.41%) the eae gene, five (29.41%) the hlyA gene and three (17.65%) harbored the st gene. All the DEC isolates were resistant to erythromycin and vancomycin; whereas, they were susceptible to ampicillin, nalidixic acid and norfloxacin. Furthermore, 64.7% of DEC isolates showed resistance to both ceftazidime and kanamycin and 88.24% of the isolates showed multidrug resistance. CONCLUSION: This study detected DEC isolates having different virulence genes, which showed single and multiple antimicrobial resistance. Given the existing poor hygienic and sanitary practices along the abattoir-to-table food chain, coupled with the habit of raw meat consumption, this result indicates a potential public and animal health risk from the pathogen and antimicrobial resistance.

Online-Assisted Survey on Antibiotic Use by Pet Owners in Dogs and Cats.

The aim of the study was two-fold: first, to collect data on the use of antibiotics in Germany for dogs and cats and, second, their owners' experiences and opinions. Using an anonymous online survey, dog and cat owners were asked about the last antibiotic administration in their pet. The inclusion criterion was any antibiotic administration within the last year. A total of 708 questionnaires from 463 dogs and 245 cats could be evaluated. Diarrhea was reported as the most common reason for antibiotic administration in dogs (18.4%). Wound infection/abscess/bite injury was the second most common reason in dogs (16.0%). In cats wound infection/abscess/bite injury was the most common reason (23.3%), followed by dental treatment (21.2%) and upper respiratory tract infections (16.7%). The most common antibiotics used systemically in both species were amoxicillin/clavulanic acid (32.5%), amoxicillin (14.8%), metronidazole (6.9%), and doxycycline (6.8%). While efficacy (99.9%) and tolerability (94.8%) were rated as most important for the choice of antibiotics, costs (51.6%) were cited as predominantly unimportant. First-line antibiotics were used significantly more often than critically important antibiotics. The majority of animal owners show awareness for avoidance of antibiotic resistance and the use of critically important antibiotics.

Prevalence and antimicrobial susceptibility of Salmonella enteritidis and Salmonella typhimurium isolated from hen eggs and quail eggs in Karaj, Iran.

BACKGROUND AND AIM: Different Salmonella serotypes are considered one of the most important food pathogens in the world. Poultry meat and eggs are the primary carriers of Salmonella in human populations. This study aimed to estimate the Salmonella enteritidis and Salmonella typhimurium contamination rates of retail hen and quail eggs in Karaj, Iran. Moreover, the antimicrobial resistance patterns of the strains were evaluated, and the efficiency of the standard culture method and multiplex polymerase chain reaction (m-PCR) were compared. MATERIALS AND METHODS: In this descriptive cross-sectional study over 1 year (Jan-Dec 2022), 150 commercial and 150 backyard hen eggs and 300 commercial quail eggs, without cracks and fractures, were collected randomly from best selling groceries in Karaj city. All samples were examined for Salmonella contamination independently by standard culture and m-PCR approaches. A standard disc diffusion method was employed to assess the antimicrobial susceptibility of the strains against 18 antimicrobial agents. RESULTS: Out of 300 examined eggs, 2 S. enteritidis strains were isolated from the shell of backyard hen eggs. The same serotype was also detected in the contents of one of these two eggs. One S. typhimurium was isolated from the shell of a commercial hen egg. Overall, the Salmonella contamination of the shell and contents was 1% and 0.3%, respectively. Salmonella was not isolated from the eggshells or the contents of the quail eggs. There was complete agreement between the results of m-PCR and the standard culture methods. Among the 18 tested antibiotics, the highest resistance was recorded for colistin (100%), followed by nalidixic acid (75%). CONCLUSION: As most Salmonella spp. are associated with human food poisoning, continuous surveillance is required to effectively reduce the risk posed by contaminated poultry eggs. Furthermore, mandatory monitoring of antimicrobial use on Iranian poultry farms is recommended.

Francisella salimarina infection in farmed cobia (Rachycentron canadum) and dusky grouper (Epinephelus marginatus) in Brazil: A case report.

This study aimed to identify and characterize isolates of Francisella salimarina associated with an outbreak on a marine fish farm in Brazil and to analyse their genetic variability and antimicrobial susceptibility. In 2021, diseased cobias (Rachycentron canadum, n = 10) and dusky groupers (Epinephelus marginatus, n = 10) were sampled and subjected to bacteriological and pathological examinations. The isolates obtained were morphologically and biochemically characterized and identified by matrix-assisted laser desorption/ionization-time of flight (MALDI-ToF) and 16S rRNA gene sequencing. The genetic diversity of these isolates was analysed using repetitive extragenic palindromic-polymerase chain reaction (REP-PCR). Antimicrobial susceptibility was assessed using the disk diffusion technique. Macroscopically, the fish presented skin ulcerations, ocular lesions, hepatomegaly and splenomegaly. A pleomorphic, gram-negative, catalase- and oxidase-positive bacterium was isolated from seven cobias and two groupers. The 16S rRNA gene sequences showed >99% coverage and identity with other deposited sequences of F. salimarina. The results of the biochemical analysis corresponded to these bacterial species. Histologically, granulomas were observed in the spleen, liver and heart of the cobias (n = 6), and necrotizing and fibrinous dermatitis and myositis were identified in some groupers (n = 2). The isolates exhibited the same banding pattern when REP-PCR was performed, indicating that they were clonally related. Finally, the antibiogram test, no inhibition halo was observed for amoxicillin and trimethoprim-sulfamethoxazole. To our knowledge, this is the first report of F. salimarina infection in cobias and dusky groupers.