Search Results (22)

Camel-associated antimicrobial resistance (AMR) is an underrecognized component of the One Health landscape, particularly in the Gulf Cooperation Council (GCC) and North Africa. Available evidence demonstrates the presence of clinically significant resistance mechanisms in camel populations, including extended-spectrum beta-lactamases, carbapenemases, colistin resistance genes, and multidrug-resistant clones. Molecular similarities between camel and human isolates suggest potential cross-species transmission and highlight camels as possible reservoirs within interconnected human–animal–environment systems. Despite documented resistance patterns, camel production systems remain largely excluded from national AMR surveillance and stewardship frameworks. This gap reflects limited camel-specific data on antimicrobial usage and structural challenges related to pastoral mobility, cross-border trade, and emerging commercial intensification. Strengthening diagnostic capacity, implementing tailored antimicrobial stewardship strategies, and integrating camels into national AMR action plans are essential to mitigate potential public health risks. Proactive inclusion of camel systems within regional AMR governance frameworks is necessary to prevent further amplification of resistance. Full article

Background: The global spread of antimicrobial resistance is one of the defining challenges of our time. Preserving the efficacy of antibiotics is a shared responsibility, which includes conducting regular surveillance studies. The poultry industry, which produces the highest quantity of animal-derived protein in the shortest time, faces significant challenges from Escherichia coli, a bacterium frequently responsible for clinical disease. Methods: This study aimed to assess the susceptibility of E. coli isolates collected from clinical cases in turkeys across Hungary to antibiotics of veterinary and public health importance using minimum inhibitory concentration (MIC) determination. Results: Over the course of one year, we analyzed a total of 70 clinical isolates. Most isolates (64.3%) were resistant to amoxicillin, and the observed 25.7% resistance to amoxicillin–clavulanic acid suggests that the majority of strains are beta-lactamase producers. The highest resistance level was observed against neomycin (74.3%). Resistance to critically important antibiotics, including enrofloxacin (28.6%), ceftriaxone (8.6%), and colistin (7.1%) raises significant public health concerns. When comparing our results with human hospital resistance data from Hungary, most findings showed comparable values, with the exception of neomycin, which exhibited markedly higher resistance in the isolates from poultry. Conclusions: Our findings underscore the necessity of regular surveillance studies, which should be periodically repeated in the future to observe temporal trends. These results should also be linked to antibiotic usage patterns, and the genetic background of multidrug-resistant strains should be further examined using next-generation sequencing techniques. This study provides critical insights into the current antimicrobial resistance landscape in the Hungarian poultry industry and highlights the urgent need for targeted interventions to prevent the dissemination of resistant strains to humans. The findings contribute valuable data for developing future AMR management strategies in veterinary and public health contexts. Full article

Background: Antimicrobial resistance (AMR) has become a serious global challenge in the 21st century. Poultry, including turkeys, are a vital source of animal-derived protein worldwide. Commensal bacterial strains in poultry can act as reservoirs for AMR, making monitoring them crucial for both veterinary and public health. Enterococcus species are emerging pathogens, particularly in severe nosocomial infections. Methods: This study aimed to assess the resistance profiles of commensal Enterococcus strains isolated (n = 470) from large-scale turkey flocks in Hungary. From each animal, two swab samples were collected: one from the oropharyngeal region near the tracheal entrance and one from the cloaca. The samples were subsequently processed, and the minimum inhibitory concentration (MIC) was determined following the Clinical and Laboratory Standards Institute (CLSI) guidelines. The tested antibiotics included amoxicillin, amoxicillin–clavulanic acid, imipenem, neomycin, doxycycline, florfenicol, tylosin, enrofloxacin, potentiated sulfonamide, vancomycin, ceftriaxone, spectinomycin, tiamulin, lincomycin, and colistin. The dilution range for MIC determination was set between 512 and 0.001 µg/mL. Results: Resistance to amoxicillin, a first-line treatment for Enterococcus infections, was low (11.1%). However, high resistance levels were observed for tylosin (62.6%), florfenicol (51.1%), doxycycline (48.7%), and enrofloxacin (45.5%). Notably, vancomycin resistance reached 15.5%, a finding consistent with global trends. Compared to human-derived Enterococcus data, resistance to aminopenicillins was significantly lower in turkey isolates, while neomycin resistance levels were comparable to those observed in human E. faecalis strains. Conclusions: The findings underscore the necessity of continuous surveillance of AMR trends in poultry production. While amoxicillin remains an effective treatment, the presence of multidrug-resistant strains and vancomycin-resistant isolates raises concerns regarding the potential dissemination of resistance genes. Future studies should incorporate next-generation sequencing to elucidate the genetic mechanisms underlying resistance. Additionally, integrating antibiotic usage data from farms may provide further insights into resistance dynamics. Strengthening antibiotic stewardship programs and fostering collaboration between veterinary and human medicine are crucial steps in addressing AMR under the One Health framework. Full article

Background: The rise in multidrug-resistant (MDR) Gram-negative bacteria (GNB) poses a critical threat to global health, exacerbated by the increased use of antibiotics during the SARS-CoV-2 pandemic. Colistin, often considered a last-resort antibiotic, has seen heightened usage, raising concerns about resistance and clinical outcomes. This study investigates the evolution of colistin resistance in GNB during the SARS-CoV-2 pandemic, with a focus on clinical outcomes in colistin-treated patients. Methods: Conducted in “Saint Spiridon” Hospital, Iasi, Romania, the study assesses antibiotic usage, trend in GNB resistance to colistin, and mortality rates across distinct pandemic phases (pre-pandemic, Delta, Omicron, and post-pandemic). A retrospective longitudinal analysis spanning 2011 to 2023 was performed. Statistical models were employed to analyze mortality risk and assess the pandemic’s impact on antimicrobial dynamics. Results: Colistin usage increased significantly during the pandemic, with the highest doses recorded during the Omicron phase. Resistance to colistin, particularly among A. baumannii and K. pneumoniae, was associated with increased mortality rates. The statistical model demonstrated robust predictive accuracy for mortality across the pandemic phases, with an AUC of 0.866 in the post-pandemic period. The findings underscore the critical role of A. baumannii as a driver of adverse outcomes, with co-infections significantly linked to systemic infections and higher mortality. Conclusions: The study highlights the evolving trends in colistin therapy and resistance, emphasizing the pandemic’s impact on antimicrobial stewardship and the persistent challenges posed by MDR pathogens. We emphasize the need for antimicrobial resistance surveillance, including the monitoring of colistin resistance, which is considered a last-resort antibiotic. Full article

Antimicrobial resistance (AMR) is a significant global health threat, with multidrug-resistant (MDR) bacterial clones becoming a major concern. Polymyxins, especially colistin, have reemerged as last-resort treatments for MDR Gram-negative infections. However, colistin use in livestock has spread mobile colistin resistance (mcr) genes, notably mcr-1, impacting human health. In consequence, its livestock use was banned in 2017, originating a natural experiment to study bacterial adaptation. The aim of this work was to analyse the changes in the mcr-1 genetic background after colistin restriction across the world. This study analyses 3163 Escherichia coli genomes with the mcr-1 gene from human and livestock hosts, mainly from Asia (n = 2621) and Europe (n = 359). Genetic characterisation identifies IncI2 (40.4%), IncX4 (26.7%), and multidrug-resistant IncHI2 (18.8%) as the most common plasmids carrying mcr-1. There were differences in plasmids between continents, with IncX4 (56.6%) being the most common in Europe, while IncI2 (44.8%) was predominant in Asia. Promoter variants related to reduced fitness costs and ISApl1 showed a distinct pattern of association that appears to be associated with adaptation to colistin restriction, which differed between continents. Thus, after the colistin ban, Europe saw a shift to specialised mcr-1 plasmids as IncX4, while ISApl1 decreased in Asia due to changes in the prevalence of the distinct promoter variants. These analyses illustrate the evolution of mcr-1 adaptation following colistin use restrictions and the need for region-specific strategies against AMR following colistin restrictions. Full article

Background: The COVID-19 pandemic posed numerous challenges to public health systems, particularly in antimicrobial stewardship. This study aimed to assess antibiotic consumption before and during the COVID-19 pandemic to evaluate the effectiveness of the implemented antimicrobial stewardship program. Methods: This retrospective study was carried out at the University Hospital in Krakow, Poland, between 1 January 2019 and 31 December 2020. A total of 80,639 patients were enrolled. Antibiotic usage was measured as the percentage of patients receiving antibiotics and the number of days of therapy (DOTs). The World Health Organization (WHO) methodology and Anatomical Therapeutic Chemical (ATC) codes and AWaRe classification were utilized. The analyzed ATC antibiotic groups included penicillins (J01CA, J01CE, J01CF, J01CR, excluding piperacillin/tazobactam), piperacillin with tazobactam-beta-lactamase inhibitor (J01CR05), third- and fourth-generation cephalosporins (J01DD, J01DE), carbapenems (J01DH), macrolides (J01FA), fluoroquinolones (J01M), colistin (J01XB01), metronidazole (J01XD01) and others (J01DF, J01DI, J01E, J01G, J01XA, J01A). In the AWaRe classification, Access, Watch and Reserve groups of antibiotics were included. Results: In 2020, 79.2% of COVID-19 patients and 40.1% of non-COVID-19 patients were treated with antibiotics, compared to 28.8% in 2019. Also, in 2020, the antibiotic consumption in non-ICU COVID-19 patients was twice as high as in non-COVID-19 patients: 50.9 vs. 38.5 DOTs/100 patient days (pds). Conversely, in the ICU, antibiotic consumption in COVID-19 patients was 112.1 DOTs/100 pds compared to 248.9 DOTs/100 pds in non-COVID-19 patients. Significant increases were observed in the usage of third- and fourth-generation cephalosporins in 2020. The analysis according to the AWaRe system revealed the highest usage of the Watch group—ranging from 61.9% to 78.7%—and very high usage of the Reserve group—from 5.8% to 11.1%—in non COVID-19 and COVID-19 patients, respectively. Conclusions: Our findings highlight substantial issues with antibiotic use both before and during the COVID-19 pandemic. The results underscore the urgent need for improved antimicrobial stewardship policy implementation. Full article

The emergence of antimicrobial resistance represents a serious threat to public health and for infections due to multidrug-resistant (MDR) microorganisms, representing one of the most important causes of death worldwide. The renewal of old antimicrobials, such as colistin, has been proposed as a valuable therapeutic alternative to the emergence of the MDR microorganisms. Although colistin is well known to present several adverse toxic effects, its usage in clinical practice has been reconsidered due to its broad spectrum of activity against Gram-negative (GN) bacteria and its important role of “last resort” agent against MDR-GN. Despite the revolutionary perspective of treatment with this old antimicrobial molecule, many questions remain open regarding the emergence of novel phenotypic traits of resistance and the optimal usage of the colistin in clinical practice. In last years, several forward steps have been made in the understanding of the resistance determinants, clinical usage, and pharmacological dosage of this molecule; however, different points regarding the role of colistin in clinical practice and the optimal pharmacokinetic/pharmacodynamic targets are not yet well defined. In this review, we summarize the mode of action, the emerging resistance determinants, and its optimal administration in the treatment of infections that are difficult to treat due to MDR Gram-negative bacteria. Full article

Escherichia coli (E. coli) is an important foodborne pathogen and a biomarker for monitoring antimicrobial resistance. Investigating the prevalence of E. coli in the poultry industry holds great importance, particularly in Henan province, a major poultry-producing region in China. Here, we investigated the antimicrobial resistance (AMR) phenotypes of E. coli strains obtained from the poultry industry in Henan, China. A total of 344 E. coli strains were isolated from 638 samples collected from seven farms, three slaughterhouses, and ten terminal markets. Approximately 96.4%, 81.7%, and 52.5% of the isolates from the farms, slaughterhouses, and terminal markets exhibited multidrug resistance. Whole-genome sequencing was performed on 169 strains to reveal their genomic characteristics. The sequence type (ST) analysis revealed that ST10 and ST156 were the most frequent types within the poultry supply chain, whereas ST10 and ST162 were commonly found across the farms, slaughterhouses, and terminal markets. Fourteen ST10 E. coli strains belonged to phylogenetic group A, while fifteen ST165 and six ST162 E. coli strains belonged to phylogenetic group B1. In addition, several antimicrobial resistance genes and virulence factor genes were identified. The bla_NDM-5 gene mediated carbapenem resistance in two E. coli strains, while mcr-1-mediated colistin resistance was detected in nine E. coli strains. Phylogenetic group A exhibited fewer virulence genes compared to other groups of E. coli. Plasmid replicons, such as IncFIB (AP001918), IncX1, IncFIC (FII), and IncFII (pHN7A8), were frequently observed. These findings provide valuable insights into the current AMR profiles of E. coli strains isolated from the poultry industry in Central China and highlight the need to implement good manufacturing practices and reduce antibiotic usage to mitigate potential risks associated with E. coli. Full article

Reports have documented antimicrobial usage in aquaculture, and the aquatic ecosystem can be considered a genetic storage site for antibiotic-resistant bacteria. This study assessed the prevalence of antimicrobial resistance (AMR) among Gram-negative bacteria recovered from retail seafood in Hiroshima, Japan. A total of 412 bacteria were isolated and screened for the presence of β-lactamases, acquired carbapenemases, and mobile colistin-resistance (mcr) genes. Forty-five (10.9%) isolates were dominated by Morganella (28%), Proteus (22%), Aeromonas (14%), Citrobacter (8%), and Escherichia (8%) and carried AMR genes. The identified AMR genes included those encoded in integrons (19), aac(6՛)-Ib (11), bla_TEM-1 (7), bla_CTX-M-like (12), bla_CTX-M-65 (2), bla_SHV-12 (1), bla_SHV-27 (1), bla_OXA-10 (1), bla_OXA-2 (1), and mcr (2). The most common clinical resistances were against ampicillin, colistin, sulfamethoxazole/trimethoprim, tetracycline, and ciprofloxacin. Multidrug resistance (MDR) occurred in 27 (60%) AMR isolates, and multiple antibiotic resistance indices ranged from 0.2 to 0.8. A conjugation experiment showed that 10 of the 11 selected MDR strains harbored conjugable plasmids, although PCR-based replicon typing described seven strains as untypable. IncF replicon was identified in MDR extended-spectrum β-lactamase-producing Escherichia coli of the pathogenic B2 phylogroup. Our findings suggest that retail seafood harbors MDR bacteria of human interest that require strict resistance surveillance in the seafood production continuum. Full article

The purpose of this study was twofold: first, to conduct a situational analysis, and second, to assess the knowledge, attitudes, and practices (KAP) of broiler poultry farmers (BPF) regarding antimicrobial use (AMU) and antimicrobial resistance (AMR). Data were collected from 500 BPF across 40 districts, representing 88.1% of Nepal’s broiler poultry population. Among these farmers, 81.0% were male, 59.6% had up to 4 years of experience in poultry farming, and 50.8% had completed at least a high school education. The most used antimicrobials on the farms were doxycycline (23.5%), neomycin (17.1%), and colistin sulfate (9.6%) out of 27 reported antimicrobials. While the BPF exhibited limited knowledge (62.6%) and practice (55.5%) related to AMU and AMR, their overall attitude toward these issues was positive (91.6%). This study also identified significant factors influencing farmers’ attitudes toward AMU and AMR. Farmers aged 31–40 showed a stronger inclination compared to other age groups (OR = 4.2, p = 0.02), and those using antimicrobials for preventive purposes had a more favorable attitude compared to those using them for other purposes (OR = 5.9, p = 0.02). In light of these findings, this study recommends the implementation of effective regulatory measures for drug usage, along with awareness programs addressing AMU and AMR to address the issue of AMR in poultry production. Full article

Antimicrobial resistance is one of the most crucial One Health topics worldwide. Consequently, various national and international surveillance programs collect data and report trends regularly. Ceftiofur, colistin and enrofloxacin belong to the most important and critical class of anti-infective medications in both human and veterinary medicine. In the present study, antimicrobial resistance was analyzed using the epidemiological cut-off (ECOFF) value on 6569 Escherichia coli isolated from pigs in Bavaria, Germany, during five years, from 2016 to 2020. The statistically relevant results regarding antimicrobial resistance revealed a decrease for colistin, an increase for enrofloxacin, and a constant level for ceftiofur. In Germany, the usage of all three antimicrobial substances in livestock has fallen by 43.6% for polypeptides, 59.0% for fluoroquinolones and 57.8% for the 3rd + 4th generation cephalosporines during this time. Despite the decline in antimicrobial usage, a reduction regarding antimicrobial resistance was solely observed for colistin. This finding illustrates that in addition to the restriction of pharmaceutical consumption, further measures should be considered. Improved biosecurity concepts, a reduction in crowding, and controlled animal movements on farms may play a key role in finally containing the resistance mechanisms of bacteria in farm animals. Full article

The increasing incidence of extended-spectrum β-lactamase (ESBL)-producing Escherichia (E.) coli in backyard chicken farming in Pakistan is of serious concern. This study aimed to assess the prevalence, antimicrobial resistance patterns and risk factors associated with ESBL avian pathogenic E. coli (APEC) isolated from backyard chickens in the Jhang district, Punjab, Pakistan. In total, 320 cloacal swabs were collected from four breeds of backyard chicken (Aseel, Golden, Misri and Necked Neck). ESBL E. coli were phenotypically identified using double disc synergy test (DDST) and corresponding genes were confirmed by multiplex polymerase chain reaction (mPCR). Out of the 320 samples, 164 (51.3%) were confirmed as E. coli, while 74 (45.1%) were characterized as ESBL E. coli. The frequency of isolation of ESBL E. coli was highest in Aseel chickens (35.1%). Of the 164 confirmed E. coli, 95.1%, 78.6%, 76.8%, 71.3%, 70.1%, 68.9%, 60.4% and 57.3% were resistant against tylosin, doxycycline, cefotaxime, enrofloxacin, colistin, trimethoprim/sulfamethoxazole, chloramphenicol and gentamicin, respectively. The ESBL gene types detected and their corresponding proportions were bla_CTX-M (54.1 %, 40/74), bla_TEM, (12.2%, 9/74) and co-existence (bla_CTX-M and bla_TEM) were shown in 33.8% (25/74). The bla_CTX-M gene sequence showed homology to bla_CTX-M-15 from clinical isolates. The mean multiple antibiotic resistance index (MARI) was found to be higher among ESBL E. coli (0.25) when compared to non-ESBL E. coli (0.17). Both free-range husbandry management system (p = 0.02, OR: 30.00, 95% CI = 1.47–611.79) and high antimicrobial usage in the last 6 months (p = 0.01, OR: 25.17, 95% CI = 1.81–348.71) were found significantly associated with isolation of ESBL-producing E. coli in the tested samples using binary logistic regression analysis. This study confirmed the potential of backyard chickens as a reservoir for ESBL E. coli in the Jhang district, Punjab, Pakistan. Full article

The emergence of colistin resistance raises growing concerns because of its use as a last-resort antimicrobial for the treatment of severe gram-negative bacterial infections in humans. Plasmid-borne mobile colistin resistance genes (mcr) are particularly worrisome due to their high propensity to spread. An mcr-9-positive Escherichia coli was isolated from a piglet in Italy, representing the first isolation of this gene from an E. coli of animal origin in the country. Whole genome sequencing (WGS) revealed that mcr-9 was borne by an IncHI2 plasmid carrying several other resistance genes. The strain was indeed phenotypically resistant to six different antimicrobial classes, including 3rd and 4th generation cephalosporins. Despite the presence of mcr-9, the isolate was susceptible to colistin, probably because of a genetic background unfavourable to mcr-9 expression. The lack of colistin resistance, coupled with the fact that the farm of origin had not used colistin in years, suggests that mcr-9 in such a multidrug-resistant strain can be maintained thanks to the co-selection of neighbouring resistance genes, following usage of different antimicrobials. Our findings highlight how a comprehensive approach, integrating phenotypical testing, targeted PCR, WGS-based techniques, and information on antimicrobial usage is crucial to shed light on antimicrobial resistance. Full article

Carbapenem-resistant Acinetobacter baumannii (CRAB) is designated as an urgent public health threat, both due to its remarkable multidrug resistance and propensity for clonal spread. This study aimed to explore the phenotypic and molecular characteristics of antimicrobial resistance in CRAB isolates (n = 73) from intensive care unit (ICU) patients in two university hospitals in Bulgaria (2018–2019). The methodology included antimicrobial susceptibility testing, PCR, whole-genome sequencing (WGS), and phylogenomic analysis. The resistance rates were as follows: imipenem, 100%; meropenem, 100%; amikacin, 98.6%; gentamicin, 89%; tobramycin, 86.3%; levofloxacin, 100%; trimethoprim–sulfamethoxazole, 75.3%; tigecycline, 86.3%; colistin, 0%; and ampicillin–sulbactam, 13.7%. All isolates harbored bla_OXA-51-like genes. The frequencies of distribution of other antimicrobial resistance genes (ARGs) were: bla_OXA-23-like, 98.6%; bla_{OXA-24/40-like}, 2.7%; armA, 86.3%; and sul1, 75.3%. The WGS of selected extensively drug-resistant A. baumannii (XDR-AB) isolates (n = 3) revealed the presence of OXA-23 and OXA-66 carbapenem-hydrolyzing class D β-lactamases in all isolates, and OXA-72 carbapenemase in one of them. Various insertion sequencies, such as ISAba24, ISAba31, ISAba125, ISVsa3, IS17, and IS6100, were also detected, providing increased ability for horizontal transfer of ARGs. The isolates belonged to the widespread high-risk sequence types ST2 (n = 2) and ST636 (n = 1) (Pasteur scheme). Our results show the presence of XDR-AB isolates, carrying a variety of ARGs, in Bulgarian ICU settings, which highlights the crucial need for nationwide surveillance, especially in the conditions of extensive antibiotic usage during COVID-19. Full article

There is little published information on antimicrobial resistance (AMR) in animals in Ghana. We determined the prevalence and factors associated with AMR, multi-drug resistance (MDR-resistance to ≥3 antimicrobial classes) and colistin resistance in Enterobacteriaceae in healthy pigs in Accra, Ghana. Rectal swabs obtained from the pigs on 20 farms from January to March 2022, were examined for Escherichia coli, Enterobacter spp. and Klebsiella pneumoniae. AMR was determined using standard microbiological techniques and the mcr-1 gene detected through molecular analysis. Enterobacteriaceae were isolated from 197 of 200 pigs: these comprised 195 E. coli isolates, 38 Enterobacter spp. and 3 K. pneumoniae, either singly or combined. Over 60% of E. coli were resistant to tetracycline, with 27% and 34% being resistant to amoxicillin/clavulanic acid and ampicillin, respectively; 23% of E. coli and 5% of Enterobacter spp. exhibited MDR phenotypes. Phenotypic colistin resistance was found in 8% of E. coli and Enterobacter spp., with the mcr-1 gene detected in half. Our study findings should be incorporated into on-going AMR, MDR and colistin resistance surveillance programs in Ghana. We further advocate for tailored-specific education for pig farmers on animal antimicrobial use and for strengthened regulatory policy on antimicrobial usage and monitoring in the animal production industry. Full article