Trends in Antimicrobial Drug Resistance of Streptococcus pneumoniae Isolates at Jordan University Hospital (2000⁻2018)

The Evolution of the Antimicrobial Resistance of Streptococcus pneumoniae in Tunisia: A Multicentric Analysis over Two Decades (2000-2019)

Background/Objectives: Streptococcus pneumoniae is a leading respiratory pathogen responsible for significant morbidity and mortality, particularly among vulnerable populations. Understanding its antimicrobial resistance patterns and serotype distribution is crucial for guiding treatment and prevention strategies. This study aims to examine these trends in S. pneumoniae isolates from Tunisia over a two-decade period (2000-2019). Methods: A retrospective time series analysis was conducted on data (n = 4284) gathered from eight university hospital centers across Tunisia. Antimicrobial susceptibility testing was performed according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. Pneumococcal serotypes were determined for a subset of samples from 2012 to 2019 (n = 903) using multiplex PCR and latex agglutination. Results: Penicillin G resistance decreased from 9-13.7% during 2000-2002 to 4.3% by 2019, while amoxicillin resistance increased until reaching 10% in 2019. Erythromycin resistance initially increased before stabilizing between 61.9% and 66.3% during 2014-2019, whereas tetracycline resistance declined from 2000 to 2008 and fluctuated around 40% during 2009-2019. Levofloxacin resistance did not exceed 1.2% throughout the study period. The most prevalent serotypes were 14, 19F, 19A, 23F, 3, 6B, 6A, and 9V. Among them, serotype 3 was the most susceptible overall. Serotypes 23F, 14, 9V, and 6B displayed the highest levels of multi-drug resistance. Conclusions: Penicillin G (high-dosage), cefotaxime, and levofloxacin are still effective against most S. pneumoniae strains in Tunisia, while erythromycin and tetracycline are not reliable options for treating pneumococcal infections. Alarming resistance rates among prevalent serotypes, except serotype 3, underscore the need for preventive measures, rational antibiotic use, and ongoing surveillance.

Public Patterns and Determinants of Antibiotic Self-Medication and Antibiotic Knowledge in Southern Jordan

Antibiotic self-medication, which refers to acquisition and using antibiotics to treat infections based on personal experience and/or without a doctor's advice or prescription, is a significant public health issue jeopardizing patient health outcomes. The purpose of the present cross-sectional online survey was to assess the frequency of self-medication among the general public in various geographical locations in southern Jordan, as well as to examine the determinants to self-medication. The survey was distributed through several social media networks over the period November-December 2022, and included demographic information as well as items related to the use and abuse of antibiotics, information sources about antibiotics, the duration of use of antibiotics, and assessment of the public knowledge about appropriate antibiotic use. Inferential analysis, such as the Chi-Square test and logistic regression, were adopted to assess the associations between the different variables with self-medication. A total of 984 respondents were enrolled in the study. Of these, 752 had been using antibiotics during the last year. However, the self-medicating cases were 413 of the 752. The main source of information about the utilization of antibiotics among participants in the survey was pharmacists. The participants commonly (36.0%) tended to use antibiotics until the symptoms disappeared. Nearly half of the respondents reported usually taking antibiotics for treating a runny nose (rhinorrhea). The logistic regression analysis indicated that self-medication with antibiotics was significantly associated with female gender (p-value < 0.001), low educational level (p-value = 0.014), rural living location (p-value 0.003), no health insurance (p-value = 0.001) and occupation (p-value = 0.005). Meanwhile age had no significant relationship to self-medication. Finally, the results revealed poor understanding of key appropriate antibiotic usage, which inevitably influences self-medication practice. It is crucial to come up with several programs and governmental policies to suppress widespread antibiotic self-medication as it will affect the health of future generations of Jordanian citizens.

A Multicenter Evaluation of Overall Susceptibility and Antimicrobial Resistance Among Streptococcus pneumoniae Isolates

PURPOSE

S. pneumoniae ranks as the fourth-most lethal pathogen globally in terms of fatalities associated with or attributable to resistance. In this study, the Antimicrobial Testing Leadership and Surveillance (ATLAS) analysis from India aims to study the overall antimicrobial susceptibility (AMS) among pneumococcal isolates collected between 2018 and 2021.

METHODS

Non-duplicate clinically significant S. pneumoniae isolates were collected between 2018 and 2021. In vitro activity of antibiotics was assessed against S. pneumoniae. Susceptibility was confirmed at an International Health Management Associates (IHMA) laboratory using supplied broth microdilution panels (Omron Microscan Systems, Inc., Omron Corp., Kyoto, Japan), according to the Clinical and Laboratory Standards Institute (CLSI) guidelines for all antibiotics.

RESULTS

Of the total 86 non-duplicate isolates of Streptococcus pneumoniae collected from the tertiary care centers, the proportion of isolates increased from 8.14% (n=7) in 2018 to 43.02% (n=37) in 2020. Most isolates (n = 18; 48.65%) were collected from the age group of 31-60 years in the year 2020. Erythromycin revealed a decrease in susceptibility from the year 2018 (71.43%) to 2020 (16.22%). A decreased susceptibility of 90% was recorded for levofloxacin in the year 2021. Meropenem revealed a decrease in susceptibility from the year 2018 (85.71%) to 2020 (35.14%). Penicillin susceptibility decreased from 37.5% in 2019 to 27.03% in the year 2020. Clindamycin indicated a 100% susceptibility in the year 2018 which then decreased to 71.88% in 2019 and 56.76% in 2020. Linezolid and vancomycin were found to have uniform susceptibility of 100% throughout the years from 2018 to 2021.

CONCLUSION

An increase in resistance to penicillin and macrolides among S. pneumoniae isolates was observed in the Indian population. Addressing the elevating rates of S. pneumoniae resistance may require pneumococcal conjugate vaccines (PCVs) with expanded serotype coverage and targeted antimicrobial stewardship efforts.

Antibiotic Resistance of Streptococcus pneumoniae in the Nasopharynx of Healthy Children Less than Five Years Old after the Generalization of Pneumococcal Vaccination in Marrakesh, Morocco

Streptococcus pneumoniae (S. pneumoniae) remains one of the most important pathogens causing childhood infections. The spread of antibiotic-resistant bacteria is a leading cause of treatment failure in children. The purpose of this investigation is to report the antibiotic and multidrug resistance (MDR) of S. pneumoniae strains isolated from healthy children throughout the years 2020–2022. Antimicrobial susceptibility testing of S. pneumoniae strains in selected antimicrobials was performed using disk diffusion and E-test methods on bloodMueller–Hinton agar. The antimicrobials tested included oxacillin, amoxicillin, ceftriaxone, norfloxacin, gentamicin, vancomycin, erythromycin, clindamycin, pristinamycin, tetracycline, chloramphenicol, and trimethoprim-sulfamethoxazole. A total of 201 S. pneumoniae strains were isolated from the nasopharynx of healthy children in Marrakesh, Morocco. The highest rate of resistance of S. pneumoniae was found in penicillin (57.2%), followed by tetracycline (20.9%), and erythromycin (17.9%). The rates of resistance to clindamycin, trimethoprim-sulfamethoxazole, and chloramphenicol were 14.9%, 4%, and 1.5%, respectively. All isolates were susceptible to norfloxacin, gentamicin, vancomycin, and pristinamycin. Approximately 17% of all S. pneumoniae strains were resistant to at least three different antibiotic families. This study showed a low rate of antibiotics resistance among nasopharyngeal S. pneumoniae strains, and it is thus essential to monitor S. pneumoniae susceptibility in healthy children.

Knowledge, Attitude and Conspiracy Beliefs of Healthcare Workers in Lebanon towards Monkeypox

The emergence of a monkeypox (MPOX) outbreak in 2022 represented the most recent recognizable public health emergency at a global level. Improving knowledge and attitude towards MPOX, particularly among healthcare workers (HCWs), can be a valuable approach in public health preventive efforts aiming to halt MPOX virus spread. The aim of the current study was to evaluate the knowledge and attitude of HCWs in Lebanon towards MPOX and to assess their conspiratorial attitude towards emerging virus infections (EVIs). The current study was based on a cross-sectional online survey distributed via Google Forms during September-December 2022 implementing a convenience sampling approach. The final study sample comprised a total of 646 HCWs: physicians (n = 171, 26.5%), pharmacists (n = 283, 43.8%), and nurses (n = 168, 26.0%), among others (n = 24, 3.7%). Variable defects in MPOX knowledge were detected, with a third of the participants having MPOX knowledge above the 75th percentile (n = 218, 33.7%). Satisfactory attitude towards MPOX (>75th percentile) was observed in less than a third of the participants (n = 198, 30.7%), while a quarter of the study sample endorsed conspiracy beliefs towards EVIs at a high level (>75th percentile, n = 164, 25.4%). Slightly more than two thirds of the participants agreed that MPOX vaccination should be used in disease prevention (n = 440, 68.1%). Better levels of MPOX knowledge and attitude were significantly associated with postgraduate education and older age. Physicians had significantly higher MPOX knowledge compared to other occupational categories. Less endorsement of conspiracies towards EVIs was significantly associated with male sex, occupation as a physician, and postgraduate education. Higher MPOX knowledge was associated with better attitude towards the disease. The current study showed unsatisfactory MPOX knowledge among Lebanese HCWs. Educational efforts can be valuable to improve the attitude towards the disease. Despite the relatively low level of embracing conspiracy beliefs regarding EVIs among HCWs in this study compared to previous studies, this area should be considered based on its potential impact on health-seeking behavior.

Serotype distribution and antimicrobial susceptibility of invasive Streptococcus pneumoniae isolates among adult and elderly population before and after introduction of pneumococcal conjugate vaccine in Casablanca, Morocco

BACKGROUND

Streptococcus pneumoniae (S. pneumoniae), remains a major cause of mortality and morbidity worldwide. The objective of this study was to determine the trends of invasive pneumococcal diseases (IPD) in adult and elderly population in Casablanca (Morocco) before and after introduction of pneumococcal conjugate vaccine (PCV) by determining the distribution of pneumococcal serotypes and antibiotic resistance profile of isolated strains.

METHOD

The proposed study is a retrospective laboratory-based surveillance of IPD in hospitalized adult (15-59 years old) and elderly (≥ 60 years old) patients in Ibn Rochd University Hospital Centre from 2007 to 2019 (13 years). All the 250 non-duplicate clinical invasive isolates from adult and elderly patients, confirmed as S. pneumoniae according to the laboratory standard identification procedures, are included in this study.

RESULTS

A significant decrease of the overall incidence in IPD was observed only in adults from 0.71 to 0.54/100000 populations (P  =  0.02) and to 0.47/100000 populations (P  =  0.0137) in the early and mature post-vaccine period respectively compared to the pre-vaccine period. Our results also showed a significant reduction in the overall prevalence of vaccine serotypes from 28.17 to 6.90% (P  =  0.0021) for the PCV-10 serotypes, and from 46.48 to 25.86% (P  =  0.0164) for the PCV-13 serotypes only in the mature post-vaccine period (2015-2019). In parallel, the rate of non-vaccine serotypes did not significantly change in the early post-vaccine period (2011-2014) while it increased considerably from 54 to 74.14% (P  =  0.0189) during the mature post-vaccine period. The rate of penicillin non-susceptible pneumococcal isolates decreased significantly from 23.94 to 8.77% (P  =  0.02) in adult patients, and the rate of cotrimoxazole non-susceptible pneumococcal isolates significantly decreased from 29.58 to 8.77% in the early post-vaccine period (P  =  0.003) and to 7.24% in the mature post-vaccine period (P  =  0.0007).

CONCLUSION

Although childhood vaccination has considerably reduced the incidence of IPD in adult population through the herd effect, IPD remain a real public health problem due to the alarming increase in non-vaccine serotypes (NVS) and the lack of herd effect among elderly population. The rate of antibiotic resistance was relatively low. Nevertheless, resistance constitutes a serious problem to the therapeutic arsenal due to the known capacity for genetic dissemination in the pneumococcus.

Penicillin- and Cephalosporin-Resistant Pneumococcal Meningitis: Treatment in the Real World and in Guidelines

To report on the therapy used for penicillin- and cephalosporin-resistant pneumococcal meningitis, we conducted an observational cohort study of patients admitted to our hospital with pneumococcal meningitis between 1977 and 2018. According to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) recommendations, we defined pneumococci as susceptible and resistant to penicillin with MIC values of ≤0.06 mg/L and > 0.06 mg/L, respectively; the corresponding values for cefotaxime (CTX) were ≤0.5 mg/L and >0.5 mg/L. We treated 363 episodes of pneumococcal meningitis during the study period. Of these, 24 had no viable strain, leaving 339 episodes with a known MIC for inclusion. Penicillin-susceptible strains accounted for 246 episodes (73%), penicillin-resistant strains for 93 (27%), CTX susceptible for 58, and CTX resistant for 35. Nine patients failed or relapsed and 69 died (20%), of whom 22% were among susceptible cases and 17% were among resistant cases. During the dexamethasone period, mortality was equal (12%) in both susceptible and resistant cases. High-dose CTX (300 mg/Kg/day) helped to treat failed or relapsed cases and protected against failure when used as empirical therapy (P = 0.02), even in CTX-resistant cases. High-dose CTX is a good empirical therapy option for pneumococcal meningitis in the presence of a high prevalence of penicillin and cephalosporin resistance, effectively treating pneumococcal strains with MICs up to 2 mg/L for either penicillin or CTX.

Conspiratorial Attitude of the General Public in Jordan towards Emerging Virus Infections: A Cross-Sectional Study Amid the 2022 Monkeypox Outbreak

Conspiracy theories accompany the emergence of infectious diseases and the 2022 multi-country monkeypox (MPX) outbreak is no exception. It is possible that the adoption of conspiracy beliefs negatively impacts health behavior. We aimed to assess the prevalence of conspiratorial attitudes towards emerging virus infections (EVIs) and the response measures aiming to control these infections among the general public in Jordan. In addition, we assessed MPX knowledge and the belief in the role of men who have sex with men (MSM) in virus spread. The online survey data were collected during 24 May 2022-28 June 2022. The survey instrument was based on previously published scales designed to measure MPX knowledge and EVI conspiracies. A total of 611 respondents formed the final study sample, with a mean age of 44 years and a majority of females (n = 433, 70.9%). On a scale ranging from -10 to +10, the median MPX knowledge score in the study sample was +3 (interquartile range: +1 to +5). Educational level was a determinant of MPX knowledge in multivariate analysis. More than 50% of the participants agreed at least to some extent with 9 out of 12 of the EVI conspiracy items. Multivariate analysis showed that embracing conspiracy beliefs about EVIs was associated with being female, and agreeing with or having no opinion regarding the role of MSM in MPX spread. The current study revealed the high prevalence of belief in conspiracies surrounding EVIs, and its accompanying intervention measures, among the general public in Jordan. In addition, a lower level of MPX knowledge was observed compared to previous studies among university students and health professionals in the country. We recommend evaluating the impact of the widely prevalent conspiracy beliefs on health aspects in future studies. This aim is particularly relevant in the Middle Eastern countries where embracing specific conspiracy ideas is a common occurrence.

Monkeypox Knowledge and Confidence in Diagnosis and Management with Evaluation of Emerging Virus Infection Conspiracies among Health Professionals in Kuwait

As the 2022 human monkeypox (HMPX) multi-country outbreak is spreading, the response of healthcare workers (HCWs) is central to mitigation efforts. The current study aimed to evaluate HMPX knowledge and confidence in diagnosis and management among HCWs in Kuwait. We used a self-administered questionnaire distributed in July-August 2022 through a snowball sampling approach. The survey items evaluated HMPX knowledge, confidence in diagnosis and management of the disease, and the belief in conspiracies regarding emerging virus infections (EVIs). The sample size was 896 HCWs: nurses (n = 485, 54.1%), pharmacists (n = 154, 17.2%), physicians (n = 108, 12.1%), medical technicians/allied health professionals (MT/AHP, n = 96, 10.7%), and dentists (n = 53, 5.9%). An overall low level of HMPX knowledge was noticed for items assessing virus transmission and non-cutaneous symptoms of the disease, with higher knowledge among physicians. Approximately one-fifth of the study sample agreed with the false notion that HMPX is exclusive to male homosexuals (n = 183, 20.4%), which was associated with lower knowledge with higher frequency among MT/AHP compared to nurses, physicians, and pharmacists. Confidence levels were low: confidence in diagnosis based on diagnostic tests (n = 449, 50.1%), confidence in the ability to manage the HMPX (n = 426, 47.5%), and confidence in the ability to diagnose HMPX clinically (n = 289, 32.3%). Higher confidence levels were found among nurses and participants with postgraduate degrees. Higher embrace of conspiracy beliefs regarding EVIs was noticed among participants with lower knowledge, and among those who agreed or were neutral/had no opinion regarding the false idea of HMPX exclusive occurrence among male homosexuals, while lower levels of belief in conspiracies were noticed among physicians, dentists, and pharmacists compared to MT/AHP. Variable levels of HMPX knowledge were observed in this study per item, with low level of knowledge regarding virus transmission. Differences in knowledge and confidence levels in diagnosis and management of HMPX should be considered in education and training aiming to prepare for outbreak response. The relatively high prevalence of embracing conspiratorial beliefs regarding EVIs is worrisome and needs proper interventions. The attitude towards male homosexuals' role in monkeypox spread should be evaluated in future studies considering the possibility of stigma and discrimination in this most-at-risk group.

Identification and molecular characterization of penicillin-nonsusceptible Streptococcus pneumoniae isolates recovered from invasive infections in a pre-pneumococcal vaccine era

BACKGROUND

Given the significant role of penicillin-nonsusceptible Streptococcus pneumoniae in inducing severe infectious diseases, identifying serotypes and genotypes that can mediate antimicrobial resistance has become a pillar of treatment strategies. This study aims to determine the correlation between the minimum inhibitory concentration of antimicrobial agents and amino acid mutations in penicillin-binding proteins. Moreover, molecular serotyping and multiple-locus variable number tandem repeat analysis typing were first-ever performed to characterize the invasive penicillin-nonsusceptible S. pneumoniae isolates in Iran.

METHODS

Of 149 isolates, antimicrobial susceptibility tests were performed against penicillin, ceftriaxone, and cefotaxime by the MIC Test Strip, and sequence analysis of the pbp genes was performed through PCR-sequencing method. All penicillin-nonsusceptible S. pneumoniae isolates were serotyped and genotyped by sequential multiplex PCR and multiple-locus variable-number tandem repeat analysis, respectively.

RESULTS

Among pneumococcal isolates, 53 isolates were classified as penicillin-nonsusceptible S. pneumoniae, of which 38 (71.7%) and 15 (28.3%) were resistant and intermediate to penicillin, respectively. Furthermore, ceftriaxone- and cefotaxime-nonsusceptible pneumococci constituted 33 (62.2%) and 29 cases (54.7%), respectively. Of note, there were 8 and 41 different serotypes and multiple-locus variable-number tandem repeat analysis types, respectively.

CONCLUSIONS

Due to the increasing resistance to antimicrobial agents, the most efficient approach to preventing pneumococcal infection mortality as vaccine-preventable diseases is focusing on wide-spectrum vaccination. Based on our findings, the 13-valent pneumococcal conjugate vaccine could considerably reduce the incidence of invasive pneumococcal diseases due to the high rate of serotype coverage.

Seeking patterns of antibiotic resistance in ATLAS, an open, raw MIC database with patient metadata

Antibiotic resistance represents a growing medical concern where raw, clinical datasets are under-exploited as a means to track the scale of the problem. We therefore sought patterns of antibiotic resistance in the Antimicrobial Testing Leadership and Surveillance (ATLAS) database. ATLAS holds 6.5M minimal inhibitory concentrations (MICs) for 3,919 pathogen-antibiotic pairs isolated from 633k patients in 70 countries between 2004 and 2017. We show most pairs form coherent, although not stationary, timeseries whose frequencies of resistance are higher than other databases, although we identified no systematic bias towards including more resistant strains in ATLAS. We sought data anomalies whereby MICs could shift for methodological and not clinical or microbiological reasons and found artefacts in over 100 pathogen-antibiotic pairs. Using an information-optimal clustering methodology to classify pathogens into low and high antibiotic susceptibilities, we used ATLAS to predict changes in resistance. Dynamics of the latter exhibit complex patterns with MIC increases, and some decreases, whereby subpopulations' MICs can diverge. We also identify pathogens at risk of developing clinical resistance in the near future.

Emerging Status of Multidrug-Resistant Bacteria and Fungi in the Arabian Peninsula

Simple Summary

The incidence and developing status of multidrug-resistant bacteria and fungi, as well as their related mortality, is reviewed by a systematic published literature search from nine countries in the Arabian Peninsula. In order to analyse the emerging status and mortality, a total of 382 research articles were selected from a comprehensive screening of 1705 papers. More than 850 deaths reported since 2010 in the Arabian Peninsula due to the infection of multidrug-resistant bacteria and fungi. Multidrug-resistant bacteria Acinetobacter baumannii, Mycobacterium tuberculosis, Staphylococcus aureus, and fungi Candida auris are the most prevalent and causing high deaths. To control these infections and associated deaths in the Arabian Peninsula, continuous preventive measures, accurate methods for early diagnosis of infection, active surveillance, constant monitoring, developing vaccines, eradicating multidrug resistance modulators, and data sharing among countries are required.

Abstract

We aimed to identify the prevalence and emerging status of multidrug-resistant bacteria and fungi and their associated mortality in nine countries in the Arabian Peninsula. Original research articles and case studies regarding multidrug-resistant bacteria and fungi in the Arabian Peninsula, published during the last 10 years, were retrieved from PubMed and Scopus. A total of 382 studies were included as per the inclusion and exclusion criteria, as well as the PRISMA guidelines, from a thorough screening of 1705 articles, in order to analyse the emerging status and mortality. The emerging nature of >120 multidrug-resistant (MDR) bacteria and fungi in the Arabian Peninsula is a serious concern that requires continuous monitoring and immediate preventive measures. More than 50% (n = 453) of multidrug-resistant, microbe-associated mortality (n = 871) in the Arabian Peninsula was due to MDR Acinetobacter baumannii, Mycobacterium tuberculosis and Staphylococcus aureus infection. Overall, a 16.51% mortality was reported among MDR-infected patients in the Arabian Peninsula from the 382 articles of this registered systematic review. MDR A. baumannii (5600 isolates) prevailed in all the nine countries of the Arabian Peninsula and was one of the fastest emerging MDR bacteria with the highest mortality (n = 210). A total of 13,087 Mycobacterium tuberculosis isolates were reported in the region. Candida auris (580 strains) is the most prevalent among the MDR fungal pathogen in the Arabian Peninsula, having caused 54 mortalities. Active surveillance, constant monitoring, the development of a candidate vaccine, an early diagnosis of MDR infection, the elimination of multidrug resistance modulators and uninterrupted preventive measures with enhanced data sharing are mandatory to control MDR infection and associated diseases of the Arabian Peninsula. Accurate and rapid detection methods are needed to differentiate MDR strain from other strains of the species. This review summarises the logical relation, prevalence, emerging status and associated mortality of MDR microbes in the Arabian Peninsula.

Confidence interval methods for antimicrobial resistance surveillance data

Background

Antimicrobial resistance (AMR) is one of the greatest global health challenges today, but burden assessment is hindered by uncertainty of AMR prevalence estimates. Geographical representation of AMR estimates typically pools data collected from several laboratories; however, these aggregations may introduce bias by not accounting for the heterogeneity of the population that each laboratory represents.

Methods

We used AMR data from up to 381 laboratories in the United States from The Surveillance Network to evaluate methods for estimating uncertainty of AMR prevalence estimates. We constructed confidence intervals for the proportion of resistant isolates using (1) methods that account for the clustered structure of the data, and (2) standard methods that assume data independence. Using samples of the full dataset with increasing facility coverage levels, we examined how likely the estimated confidence intervals were to include the population mean.

Results

Methods constructing 95% confidence intervals while accounting for possible within-cluster correlations (Survey and standard methods adjusted to employ cluster-robust errors), were more likely to include the sample mean than standard methods (Logit, Wilson score and Jeffreys interval) operating under the assumption of independence. While increased geographical coverage improved the probability of encompassing the mean for all methods, large samples still did not compensate for the bias introduced from the violation of the data independence assumption.

Conclusion

General methods for estimating the confidence intervals of AMR rates that assume data are independent, are likely to produce biased results. When feasible, the clustered structure of the data and any possible intra-cluster variation should be accounted for when calculating confidence intervals around AMR estimates, in order to better capture the uncertainty of prevalence estimates.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13756-021-00960-5.

Antimicrobial resistance in clinical bacterial isolates from horses in the UK

BACKGROUND

Surveillance of antimicrobial resistance (AMR) in horses is important to aid empirical treatment decisions and highlight emerging AMR threats.

OBJECTIVE

To describe the AMR patterns of common groups of bacteria from clinical submissions from horses in the UK during 2018, and to determine how this varies by sample site and type of submitting veterinary practice.

STUDY DESIGN

Prospective observational study.

METHODS

All data on bacterial culture and subsequent antimicrobial susceptibility testing (AST) collected in 2018 from six large equine diagnostic laboratories were included. Resistance patterns were analysed including resistance to 1 or 2 antimicrobial classes, multidrug resistance (MDR), extensively drug resistant (XDR), resistance to highest priority critically important antimicrobials and isolates where there was no readily available treatment for adult horses in the UK. Submitting practices were classified according to whether they treated referral cases or not (first opinion). Comparisons between proportions and resistance for each bacterial group and sample site was performed using Chi-squared (or Fisher's exact test).

RESULTS

A total of 6,018 bacterial isolates from 4,038 diagnostic submissions were included from respiratory (n = 1555), urogenital (n = 1,010), skin/hair/wound/abscess (n = 753), surgical site infection (SSI) /catheter-related-infection (CRI) /orthopaedic infections (n = 347) and unknown/'other' submissions (n = 373). There were 2,711 Gram-negative isolates and 3,307 Gram-positive isolates. Prevalence of MDR for E. coli was 31.7%, Staphylococcus spp. 25.3% and > 25% for the majority of bacterial isolates from SSI/CRI/orthopaedic submissions. For Enterococcus spp. there was no readily available treatment for adult horses in the UK in 30.2% of positive submissions. MDR was significantly higher from referral hospital than first opinion submissions for the majority of pathogens (except Actinobacillus spp. and Pasteurella spp. and β-haemolytic Streptococcus spp.).

MAIN LIMITATIONS

Since culture and susceptibility results are not systematic analyses based on harmonised methods, selection bias could impact the findings.

CONCLUSIONS

Ongoing surveillance is essential to understand emerging patterns of resistance. MDR is high in SSI/CRI/orthopaedic infections, which is important for hospital biosecurity and guiding treatment decisions. Harmonisation of diagnostic procedures and interpretation of results amongst veterinary laboratories will improve AMR surveillance and data comparison among laboratories.