The role of surveillance systems in confronting the global crisis of antibiotic-resistant bacteria

Integrated surveillance systems for antibiotic resistance in a One Health context: a scoping review

BACKGROUND

Antibiotic resistance (ABR) has emerged as a major threat to health. Properly informed decisions to mitigate this threat require surveillance systems that integrate information on resistant bacteria and antibiotic use in humans, animals, and the environment, in line with the One Health concept. Despite a strong call for the implementation of such integrated surveillance systems, we still lack a comprehensive overview of existing organizational models for integrated surveillance of ABR. To address this gap, we conducted a scoping review to characterize existing integrated surveillance systems for ABR.

METHODS

The literature review was conducted using the PRISMA guidelines. The selected integrated surveillance systems were assessed according to 39 variables related to their organization and functioning, the socio-economic and political characteristics of their implementation context, and the levels of integration reached, together with their related outcomes. We conducted two distinct, complementary analyses on the data extracted: a descriptive analysis to summarize the characteristics of the integrated surveillance systems, and a multiple-correspondence analysis (MCA) followed by a hierarchical cluster analysis (HCA) to identify potential typology for surveillance systems.

RESULTS

The literature search identified a total of 1330 records. After the screening phase, 59 references were kept from which 14 integrated surveillance systems were identified. They all operate in high-income countries and vary in terms of integration, both at informational and structural levels. The different systems combine information from a wide range of populations and commodities -in the human, animal and environmental domains, collection points, drug-bacterium pairs, and rely on various diagnostic and surveillance strategies. A variable level of collaboration was found for the governance and/or operation of the surveillance activities. The outcomes of integration are poorly described and evidenced. The 14 surveillance systems can be grouped into four distinct clusters, characterized by integration level in the two dimensions. The level of resources and regulatory framework in place appeared to play a major role in the establishment and organization of integrated surveillance.

CONCLUSIONS

This study suggests that operationalization of integrated surveillance for ABR is still not well established at a global scale, especially in low and middle-income countries and that the surveillance scope is not broad enough to obtain a comprehensive understanding of the complex dynamics of ABR to appropriately inform mitigation measures. Further studies are needed to better characterize the various integration models for surveillance with regard to their implementation context and evaluate the outcome of these models.

Cas12a/Guide RNA-Based Platform for Rapidly and Accurately Detecting blaKPC Gene in Carbapenem-Resistant Enterobacterales

Purpose

Accurate detection and identification of pathogens and their associated resistance mechanisms are essential prerequisites for implementing precision medicine in the management of Carbapenem-resistant Enterobacterales (CRE). Among the various resistance mechanisms, the production of KPC carbapenemase is the most prevalent worldwide. Consequently, this study aims to develop a convenient and precise nucleic acid detection platform specifically for the blaKPC gene.

Methods

The initial phase of our research methodology involved developing a CRISPR/Cas12a detection framework, which was achieved by designing highly specific single-guide RNAs (sgRNAs) targeting the blaKPC gene. To enhance the sensitivity of this system, we incorporated three distinct amplification techniques-polymerase chain reaction (PCR), loop-mediated isothermal amplification (LAMP), and recombinase polymerase amplification (RPA)-into the CRISPR/Cas12a framework. Subsequently, we conducted a comparative analysis of the sensitivity and specificity of these three amplification methods when used in combination with the CRISPR/Cas12a system. Additionally, we assessed the clinical applicability of the methodologies by evaluating fluorescence readouts from 80 different clinical isolates. Furthermore, we employed lateral flow assay technology to provide a visual representation of the results, facilitating point-of-care testing.

Results

Following a comparative analysis of the sensitivity and specificity of the three methods, we identified the RPA-Cas12a approach as the optimal detection technique. Our findings demonstrated that the limit of detection (LoD) of the RPA-Cas12a platform was 1 aM (~1 copy/µL) for plasmid DNA and 5 × 10³ fg/µL for genomic DNA. Furthermore, both the sensitivity and specificity of the platform achieved 100% upon validation with 80 clinical isolates.

Conclusion

These findings suggest that the developed RPA-Cas12a platform represents a promising tool for the cost-effective, convenient, and accurate detection of the blaKPC gene.

Clinical and molecular epidemiology of carbapenem-resistant Enterobacteriaceae in pediatric inpatients in South China

IMPORTANCE

This study assessed the clinical and molecular epidemiology of carbapenem-resistant Enterobacteriaceae in pediatric inpatients at three hospitals in South China by means of screening stool samples for carbapenem-resistant genes and a nested case-control study to determine risk factors for carriage of carbapenem-resistant Enterobacteriaceae. Of 4,033 fecal samples screened, 158 (3.92%) were positive for CRE, including Escherichia coli (51.27 %), Klebsiella pneumoniae (37.97%), and Enterobacter cloacae (6.96%). The most common carbapenemase genes harbored by gastrointestinal CRE strains were blaNDM-5, blaNDM-1, and blaIMP-4. Hematological malignancies, respiratory diseases, otolaryngological diseases, nervous system diseases, oral administration of third-generation cephalosporins, and the combined use of two or more antibiotics were independently associated with CRE colonization.

Monooxygenases and Antibiotic Resistance: A Focus on Carbapenems

Carbapenems are a group of broad-spectrum beta-lactam antibiotics that in many cases are the last effective defense against infections caused by multidrug-resistant bacteria, such as some strains of Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii. Resistance to carbapenems has emerged and is beginning to spread, becoming an ongoing public-health problem of global dimensions, causing serious outbreaks, and dramatically limiting treatment options. This paper reviews the role of flavin monooxygenases in antibiotic resistance, with a specific focus on carbapenem resistance and the recently discovered mechanism mediated by Baeyer-Villiger monooxygenases. Flavin monooxygenases are enzymes involved in the metabolism and detoxification of compounds, including antibiotics. Understanding their role in antibiotic resistance is crucial. Carbapenems are powerful antibiotics used to treat severe infections caused by multidrug-resistant bacteria. However, the rise of carbapenem-resistant strains poses a significant challenge. This paper explores the mechanisms by which flavin monooxygenases confer resistance to carbapenems, examining molecular pathways and genetic factors. Additionally, this paper highlights the discovery of Baeyer-Villiger monooxygenases' involvement in antibiotic resistance. These enzymes catalyze the insertion of oxygen atoms into specific chemical bonds. Recent studies have revealed their unexpected role in promoting carbapenem resistance. Through a comprehensive analysis of the literature, this paper contributes to the understanding of the interplay between flavin monooxygenases, carbapenem resistance, and Baeyer-Villiger monooxygenases. By exploring these mechanisms, it aims to inform the development of strategies to combat antibiotic resistance, a critical global health concern.

What are the missing pieces needed to stop antibiotic resistance?

As recognized by several international agencies, antibiotic resistance is nowadays one of the most relevant problems for human health. While this problem was alleviated with the introduction of new antibiotics into the market in the golden age of antimicrobial discovery, nowadays few antibiotics are in the pipeline. Under these circumstances, a deep understanding on the mechanisms of emergence, evolution and transmission of antibiotic resistance, as well as on the consequences for the bacterial physiology of acquiring resistance is needed to implement novel strategies, beyond the development of new antibiotics or the restriction in the use of current ones, to more efficiently treat infections. There are still several aspects in the field of antibiotic resistance that are not fully understood. In the current article, we make a non-exhaustive critical review of some of them that we consider of special relevance, in the aim of presenting a snapshot of the studies that still need to be done to tackle antibiotic resistance.

Cracking the Code: Unveiling the Diversity of Carbapenem-Resistant Klebsiella pneumoniae Clones in the Arabian Peninsula through Genomic Surveillance

The rise of antimicrobial resistance is a global challenge that requires a coordinated effort to address. In this study, we examined the genetic similarity of carbapenem-resistant Klebsiella pneumoniae (CRKP) in countries belonging to the Gulf Cooperation Council (GCC) to gain a better understanding of how these bacteria are spreading and evolving in the region. We used in silico genomic tools to investigate the occurrence and prevalence of different types of carbapenemases and their relationship to specific sequence types (STs) of CRKP commonly found in the region. We analyzed 720 publicly available genomes of multi-drug resistant K. pneumoniae isolates collected from six GCC countries between 2011 and 2020. Our findings showed that ST-14 and ST-231 were the most common STs, and 51.7% of the isolates carried bla_OXA-48-like genes. Additionally, we identified rare carbapenemase genes in a small number of isolates. We observed a clonal outbreak of ST-231 in Oman, and four Saudi isolates were found to have colistin resistance genes. Our study offers a comprehensive overview of the genetic diversity and resistance mechanisms of CRKP isolates in the GCC region that could aid in developing targeted interventions to combat this pressing global issue.

Molecular Dynamic Analysis of Carbapenem-Resistant Klebsiella pneumonia’s Porin Proteins with Beta Lactam Antibiotics and Zinc Oxide Nanoparticles

To prevent the rapidly increasing prevalence of bacterial resistance, it is crucial to discover new antibacterial agents. The emergence of Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae has been associated with a higher mortality rate in gulf union countries and worldwide. Compared to physical and chemical approaches, green zinc oxide nanoparticle (ZnO-NP) synthesis is thought to be significantly safer and more ecofriendly. The present study used molecular dynamics (MD) to examine how ZnO-NPs interact with porin protein (GLO21), a target of β-lactam antibiotics, and then tested this interaction in vitro by determining the zone of inhibition (IZ), minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC), as well as the alteration of KPC’s cell surface. The nanoparticles produced were characterized by UV-Vis spectroscopy, zetasizer, Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). In silico investigation was conducted using a variety of computational techniques, including Autodock Vina for protein and ligand docking and Desmond for MD simulation. The candidate ligands that interact with the GLO21 protein were biosynthesized ZnO-NPs, meropenem, imipenem, and cefepime. Analysis of MD revealed that the ZnO-NPs had the highest log P value (−9.1 kcal/mol), which indicates higher permeability through the bacterial surface, followed by cefepime (−7.9 kcal/mol), meropenem (−7.5 kcal/mol), and imipenem (−6.4 kcal/mol). All tested compounds and ZnO-NPs possess similar binding sites of porin proteins. An MD simulation study showed a stable system for ZnO-NPs and cefepime, as confirmed by RMSD and RMSF values during 100 ns trajectories. The test compounds were further inspected for their intersection with porin in terms of hydrophobic, hydrogen, and ionic levels. In addition, the stability of these bonds were measured by observing the protein–ligand contact within 100 ns trajectories. ZnO-NPs showed promising results for fighting KPC, represented in MIC (0.2 mg/mL), MBC (0.5 mg/mL), and ZI (24 mm diameter). To draw the conclusion that ZnO-NP is a potent antibacterial agent and in order to identify potent antibacterial drugs that do not harm human cells, further in vivo studies are required.

Multidrug-resistant Acinetobacter baumannii in healthcare settings in Africa

The emergence of multidrug-resistant Acinetobacter baumannii is a major concern to healthcare providers and facilities in many parts of the world. This bacterial pathogen is commonly implicated in hospital-acquired infections, particularly in critically ill patients admitted to the intensive care unit (ICU). The extensive use of antibiotics, particularly in ICUs, and the lack of proper infection control interventions in many hospitals have led to an increased emergence of multidrug-resistant A. baumannii. Infections due to multidrug-resistant A. baumannii are associated with prolonged hospital stays and high morbidity and mortality, particularly among hospitalized ICU patients. The lack of antibiotic stewardship programmes in many healthcare facilities has exacerbated the burden of A. baumannii infections in many parts of Africa. This review discusses the prevalence and antibiotic-resistance pattern of the multidrug-resistant A. baumannii, and the possible ways to address or minimise its emergence in healthcare settings in Africa.

Prevalence of ESKAPE pathogens in the environment: Antibiotic resistance status, community-acquired infection and risk to human health

The ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) pathogens are characterised by increased levels of resistance towards multiple classes of first line and last-resort antibiotics. Although these pathogens are frequently isolated from clinical environments and are implicated in a variety of life-threatening, hospital-associated infections; antibiotic resistant ESKAPE strains have been isolated from environmental reservoirs such as surface water, wastewater, food, and soil. Literature on the persistence and subsequent health risks posed by the ESKAPE isolates in extra-hospital settings is however, limited and the current review aims to elucidate the primary reservoirs of these pathogens in the environment, their antibiotic resistance profiles, and the link to community-acquired infections. Additionally, information on the current state of research regarding health-risk assessments linked to exposure of the ESKAPE pathogens in the natural environment, is outlined.

Evidence of a decrease in sales of antimicrobials of very high importance for humans in dairy herds after a new regulation restricting their use in Quebec, Canada

In the province of Quebec, Canada, a new regulation restricting usage of antimicrobials of very high importance for human health (Health Canada: category 1 antimicrobials) in production animals is effective since February 2019. The objective of this study was to estimate changes in AM sales in dairy herds after the implementation of the regulation. Therefore, invoice data were extracted from veterinary software, Vet-Expert, used by most dairy veterinarians in the province of Quebec, and antimicrobial quantities were transformed in Canadian defined course doses for cattle (DCDbovCA). The sum of antimicrobials sales monthly in each herd was estimated in DCDbovCA from June 2016 to May 2020. To evaluate the herd-level change in AM sales and the impact of different factors, the number of DCDbovCA by herd from June 2017 to May 2018 (pre-regulation period) were compared with those of June 2019 to May 2020 (post-regulation period). Total category 1 AM sales of 3,569 Quebec's herds went from a range of 14,258 to 21,528 DCDbovCA/month to a range of 1,494 to 4,707 DCDbovCA/month after the implementation of the new regulation. Moreover, using data from 3,337 herds, we estimated a mean (95% confidence interval) reduction in 19 DCDbovCA/herd-year (14.8, 24.2), while the pre-regulation herd-level category 1 AM sales was 26 DCDbovCA/herd-year. This reduction was achieved without evidence of an increase in other antimicrobials. Finally, the veterinary facility associated with the herd was an important determinant of the herd-level reduction in category 1 antimicrobials. This study was the first to quantify a significant reduction in category 1 AM sales following the implementation of a restrictive regulation in dairy production in Canada. These results demonstrate that such an approach is effective to reduce the sales of a specific category of antimicrobial in animal production.

Exploiting genomics to mitigate the public health impact of antimicrobial resistance

Antimicrobial resistance (AMR) is a major global public health threat, which has been largely driven by the excessive use of antimicrobials. Control measures are urgently needed to slow the trajectory of AMR but are hampered by an incomplete understanding of the interplay between pathogens, AMR encoding genes, and mobile genetic elements at a microbial level. These factors, combined with the human, animal, and environmental interactions that underlie AMR dissemination at a population level, make for a highly complex landscape. Whole-genome sequencing (WGS) and, more recently, metagenomic analyses have greatly enhanced our understanding of these processes, and these approaches are informing mitigation strategies for how we better understand and control AMR. This review explores how WGS techniques have advanced global, national, and local AMR surveillance, and how this improved understanding is being applied to inform solutions, such as novel diagnostic methods that allow antimicrobial use to be optimised and vaccination strategies for better controlling AMR. We highlight some future opportunities for AMR control informed by genomic sequencing, along with the remaining challenges that must be overcome to fully realise the potential of WGS approaches for international AMR control.

Plethora of Resistance Genes in Carbapenem-Resistant Gram-Negative Bacteria in Greece: No End to a Continuous Genetic Evolution

Carbapenem-resistant Gram-negative bacteria are a public health threat that requires urgent action. The fact that these pathogens commonly also harbor resistance mechanisms for several other antimicrobial classes further reduces patient treatment options. The present study aimed to provide information regarding the multidrug resistance genetic background of carbapenem-resistant Gram-negative bacteria in Central Greece. Strains from a tertiary care hospital, collected during routine practice, were characterized using a DNA microarray-based assay. Various different resistance determinants for carbapenems, other beta-lactams, aminoglycosides, quinolones, trimethoprim, sulfonamides and macrolides were detected among isolates of the same sequence type. Eighteen different multidrug resistance genomic profiles were identified among the twenty-four K. pneumoniae ST258, seven different profiles among the eight K. pneumoniae ST11, four profiles among the six A. baumannii ST409 and two among the three K. oxytoca. This report describes the multidrug resistance genomic background of carbapenem-resistant Gram-negative bacteria from a tertiary care hospital in Central Greece, providing evidence of their continuous genetic evolution.

Antibiotic resistance in the patient with cancer: Escalating challenges and paths forward

Infection is the second leading cause of death in patients with cancer. Loss of efficacy in antibiotics due to antibiotic resistance in bacteria is an urgent threat against the continuing success of cancer therapy. In this review, the authors focus on recent updates on the impact of antibiotic resistance in the cancer setting, particularly on the ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.). This review highlights the health and financial impact of antibiotic resistance in patients with cancer. Furthermore, the authors recommend measures to control the emergence of antibiotic resistance, highlighting the risk factors associated with cancer care. A lack of data in the etiology of infections, specifically in oncology patients in United States, is identified as a concern, and the authors advocate for a centralized and specialized surveillance system for patients with cancer to predict and prevent the emergence of antibiotic resistance. Finding better ways to predict, prevent, and treat antibiotic-resistant infections will have a major positive impact on the care of those with cancer.

Resistance in Enterobacterales is higher among people with HIV

BACKGROUND

Multidrug-resistant Enterobacterales (MDR-E) are important pathogens. People with human immunodeficiency virus (HIV) may be at greater risk for MDR-E infection given relatively high antibiotic exposure and burden of comorbidities.

METHODS

Analyses were conducted using data collected on 36,521 patients in a healthcare system in North Carolina, who had at least 1 clinical culture with growth of an Enterobacterales species from 2000-2018; 440 were people with HIV infection (PWH). We used generalized linear models to estimate prevalence ratios and differences contrasting patients with and without HIV for resistance to individual antibiotic classes, as well as MDR-E. We assessed trends in prevalence over time by calculating the 5-year moving average and fitting restricted cubic spline models.

RESULTS

The overall prevalence of MDR-E was higher among PWH (21.5% [95% CI: 18.2%-25.1%]) versus patients without HIV (16.5% [95% CI: 16.2%-16.9%], with an adjusted prevalence ratio of 1.38 (95% CI: 1.14-1.65). PWH had higher rates of antimicrobial resistance than patients without HIV for all antibiotic classes analyzed, including penicillins, penicillin/beta-lactamase inhibitor combinations, and sulfonamides. MDR-E prevalence was 3 to 10 percentage points higher among PWH than patients without HIV throughout the study period based on the 5-year moving average.

CONCLUSION

In a large clinical study population in the southeastern US from 2000-2018, the prevalence of antibacterial resistance among Enterobacterales was consistently higher among PWH than patients without HIV. These data highlight the importance of identifying and mitigating the factors contributing to antimicrobial resistance in PWH, given the potential clinical consequences of these resistant pathogens.

Nationwide Surveillance and Molecular Characterization of Critically Drug-Resistant Gram-Negative Bacteria: Results of the Research University Network Thailand Study

A large-scale surveillance is an important measure to monitor the regional spread of antimicrobial resistance. We prospectively studied the prevalence and molecular characteristics of clinically important Gram-negative bacilli, including Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii complex (ABC), and Pseudomonas aeruginosa, from blood, respiratory tract, urine, and sterile sites at 47 hospitals across Thailand. Among 187,619 isolates, 93,810 isolates (50.0%) were critically drug resistant, of which 12,915 isolates (13.8%) were randomly selected for molecular characterization. E. coli was most commonly isolated from all specimens, except the respiratory tract, in which ABC was predominant. Prevalence of extended-spectrum cephalosporin resistance (ESCR) was higher in E. coli (42.5%) than K. pneumoniae (32.0%), but carbapenem-resistant (CR)-K. pneumoniae (17.2%) was 4.5-fold higher than CR-E. coli (3.8%). The majority of ESCR/CR-E. coli and K. pneumoniae isolates carried bla_CTX-M (64.6% to 82.1%). bla_NDM and bla_OXA-48-like were the most prevalent carbapenemase genes in CR-E. coli/CR-K. pneumoniae (74.9%/52.9% and 22.4%/54.1%, respectively). In addition, 12.9%/23.0% of CR-E. coli/CR-K. pneumoniae cocarried bla_NDM and bla_OXA-48-like. Among ABC isolates, 41.9% were extensively drug resistant (XDR) and 35.7% were multidrug resistant (MDR), while P. aeruginosa showed XDR/MDR at 6.3%/16.5%. A. baumannii was the most common species among ABC isolates. The major carbapenemase gene in MDR-A. baumannii/XDR-A. baumannii was bla_OXA-23-like (85.8%/93.0%), which had much higher rates than other ABC species. bla_IMP, bla_VIM, bla_OXA-40-like, and bla_OXA-58-like were also detected in ABC at lower rates. The most common carbapenemase gene in MDR/XDR-P. aeruginosa was bla_IMP (29.0%/30.6%), followed by bla_VIM (9.5%/25.3%). The findings reiterate an alarming situation of drug resistance that requires serious control measures.

resistancebank.org, an open-access repository for surveys of antimicrobial resistance in animals

Antimicrobial resistance (AMR) is a growing threat to the health of humans and animals that requires global actions. In high-income countries, surveillance systems helped inform policies to curb AMR in animals. In low- and middle-income countries (LMICs), demand for meat is rising, and developing policies against AMR is urgent. However, surveillance of AMR is at best nascent, and the current evidence base to inform policymakers is geographically heterogeneous. We present resistancebank.org, an online platform that centralizes information on AMR in animals from 1,285 surveys from LMICs. Surveys were conducted between 2000 and 2019 and include 22,403 resistance rates for pathogens isolated from chickens, cattle, sheep, and pigs. The platform is built as a shiny application that provides access to individual surveys, country-level reports, and maps of AMR at 10 × 10 kilometers resolution. The platform is accessed via any internet browser and enables users to upload surveys to strengthen a global database. resistancebank.org aims to be a focal point for sharing AMR data in LMICs and to help international funders prioritize their actions.

Comparison of Antimicrobial-Resistant Escherichia coli Isolates from Urban Raccoons and Domestic Dogs

Wildlife can be exposed to antimicrobial-resistant bacteria (ARB) via multiple pathways. Spatial overlap with domestic animals is a prominent exposure pathway. However, most studies of wildlife-domestic animal interfaces have focused on livestock and little is known about the wildlife-companion animal interface. Here, we investigated the prevalence and phylogenetic relatedness of extended-spectrum cephalosporin-resistant (ESC-R) Escherichia coli from raccoons (Procyon lotor) and domestic dogs (Canis lupus familiaris) in the metropolitan area of Chicago, IL, USA. To assess the potential importance of spatial overlap with dogs, we explored whether raccoons sampled at public parks (i.e., parks where people and dogs could enter) differed in prevalence and phylogenetic relatedness of ESC-R E. coli to raccoons sampled at private parks (i.e., parks where people and dogs could not enter). Raccoons had a significantly higher prevalence of ESC-R E. coli (56.9%) than dogs (16.5%). However, the richness of ESC-R E. coli did not vary by host species. Further, core single-nucleotide polymorphism (SNP)-based phylogenetic analyses revealed that isolates did not cluster by host species, and in some cases displayed a high degree of similarity (i.e., differed by less than 20 core SNPs). Spatial overlap analyses revealed that ESC-R E. coli were more likely to be isolated from raccoons at public parks than raccoons at private parks, but only for parks located in suburban areas of Chicago, not urban areas. That said, ESC-R E. coli isolated from raccoons did not genetically cluster by park of origin. Our findings suggest that domestic dogs and urban/suburban raccoons can have a diverse range of ARB, some of which display a high degree of genetic relatedness (i.e., differ by less than 20 core SNPs). Given the differences in prevalence, domestic dogs are unlikely to be an important source of exposure for mesocarnivores in urbanized areas. IMPORTANCE Antimicrobial-resistant bacteria (ARB) have been detected in numerous wildlife species across the globe, which may have important implications for human and animal health. Wildlife can be exposed to ARB via numerous pathways, including via spatial overlap with domestic animals. However, the interface with domestic animals has mostly been explored for livestock and little is known about the interface between wild animals and companion animals. Our work suggests that urban and suburban wildlife can have similar ARB to local domestic dogs, but local dogs are unlikely to be a direct source of exposure for urban-adapted wildlife. This finding is important because it underscores the need to incorporate wildlife into antimicrobial resistance surveillance efforts, and to investigate whether certain urban wildlife species could act as additional epidemiological pathways of exposure for companion animals, and indirectly for humans.

An integrated surveillance network for antimicrobial resistance, India

Objective

To assess the preparedness of veterinary laboratories in India to participate in an integrated antimicrobial resistance surveillance network and to address gaps in provision identified.

Methods

The Indian Council of Medical Research and the Indian Council of Agricultural Research collaborated: (i) to select eight nationally representative veterinary microbiology laboratories whose capacity for participating in an integrated antimicrobial resistance surveillance network would be assessed using a standardized tool; (ii) to identify gaps in provision from the assessment findings; and (iii) to develop a plan, and take the necessary steps to address these gaps in consultation with participating organizations.

Findings

The main gaps in provision identified were: (i) a lack of dedicated funding for antimicrobial resistance surveillance; (ii) the absence of standard guidelines for antimicrobial susceptibility testing; (iii) a shortage of reference strains for testing and quality assurance; and (iv) the absence of mechanisms for sharing data. We addressed these gaps by creating a veterinary standard operating procedure for antimicrobial susceptibility testing, by carrying out a validation exercise to identify problems with implementing the procedure and by conducting capacity-building workshops for veterinary laboratories.

Conclusion

Antimicrobial resistance surveillance networks depend on the availability of accurate, quality-controlled testing. The challenges identified in creating an integrated surveillance network for India can be overcome by developing a comprehensive plan for improving laboratory capacity in human, veterinary and environmental sectors that is supported by the necessary funds. The study’s findings may provide guidance for other low- and middle-income countries planning to develop a similar network.

Surveillance of Resistance to New Antibiotics in an Era of Limited Treatment Options

As with any health threat, our ability to respond to the emergence and spread of antimicrobial resistance depends on our ability to understand the scale of the problem, magnitude, geographical spread, and trends over time. This is especially true for resistance emergence to newer antibiotics coming to the market as last-resort treatments. Yet current antibiotic surveillance systems are limited to monitoring resistance to commonly prescribed drugs that have been on the market for a long time. This qualitative study determined the essential elements and requirements of antimicrobial resistance surveillance for new antibiotics based on literature review, interviews and expert consensus. After an extensive mapping exercise, 10 experts participated in a modified Delphi consultation to identify consensus on all elements required for surveillance of resistance to novel antibiotics. The main findings indicate that there is a need for a two-phase system; an early alert system transitioning to routine surveillance, led by the public sector to gather and share essential data on resistance to newer antibiotics in a transparent manner. The system should be decentralized, run largely from national level, but be coordinated by an arm of an existing international public health institution. Priority should be given to monitoring emergence of resistance among already multi-drug resistant pathogens causing infections, over a broader selection of pathogens to maximize clinical impact. In conclusion, we cannot rely on current AMR surveillance systems to monitor resistance emergence to new antibiotics. A new, public system should be set-up, starting with a focus on detecting resistance emergence, but expanding to a more comprehensive surveillance as soon as there is regional spread of resistance to the new antibiotic. This article provides a framework based on expert agreement, which could guide future initiatives.

Evaluating the Integration of One Health in Surveillance Systems for Antimicrobial Use and Resistance: A Conceptual Framework

It is now widely acknowledged that surveillance of antimicrobial resistance (AMR) must adopt a "One Health" (OH) approach to successfully address the significant threats this global public health issue poses to humans, animals, and the environment. While many protocols exist for the evaluation of surveillance, the specific aspect of the integration of a OH approach into surveillance systems for AMR and antimicrobial Use (AMU), suffers from a lack of common and accepted guidelines and metrics for its monitoring and evaluation functions. This article presents a conceptual framework to evaluate the integration of OH in surveillance systems for AMR and AMU, named the Integrated Surveillance System Evaluation framework (ISSE framework). The ISSE framework aims to assist stakeholders and researchers who design an overall evaluation plan to select the relevant evaluation questions and tools. The framework was developed in partnership with the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS). It consists of five evaluation components, which consider the capacity of the system to: [1] integrate a OH approach, [2] produce OH information and expertise, [3] generate actionable knowledge, [4] influence decision-making, and [5] positively impact outcomes. For each component, a set of evaluation questions is defined, and links to other available evaluation tools are shown. The ISSE framework helps evaluators to systematically assess the different OH aspects of a surveillance system, to gain comprehensive information on the performance and value of these integrated efforts, and to use the evaluation results to refine and improve the surveillance of AMR and AMU globally.

Policy implications for awareness gaps in antimicrobial resistance (AMR) and antimicrobial use among commercial Nepalese poultry producers

BACKGROUND

Nepal's poultry industry has increased with a growing middle class, which has translated to an increase in antimicrobial consumption and thus a rise in antimicrobial resistance (AMR). Describing and understanding antimicrobial use practices among commercial poultry producers in Nepal may help minimize the risks of AMR development in both humans and animals and determine the effectiveness of relevant policies.

METHODS

From July to August 2018, poultry farmers were randomly recruited from Nepal's Chitwan District to participate in a cross-sectional study. The lead producer in each poultry operation was administered a quantitative structured-survey via a 30-min interview. Participants were asked to provide demographics, production practices, and knowledge about their antimicrobial use practices. Descriptive data analysis was performed to obtain frequencies and compare practices.

RESULTS

In total, 150 commercial poultry producers of whom raised between 300 and 40,000 birds completed the interviews. Only 33% (n = 49) of producers reported knowing what AMR was, and among them only 50% (n = 25) consulted a veterinarian for treatment options. Antimicrobial administration for growth promotion was still employed by 13% of poultry producers. Similarly, critically important antimicrobial drugs, specifically colistin, were identified at 35% of participating operations. Producers reported low overall understanding and compliance of withdrawal periods (n = 41; 27%), which may result in both AMR development and adverse health reactions among consumers who ingest antimicrobial residues. Although Nepal has publicized antimicrobial use policies and awareness campaigns to instill healthy production practices, most producers (82%) were unaware of them.

CONCLUSION

Many Nepalese poultry producers lack overall antimicrobial use and AMR awareness, which is evidenced by low antimicrobial withdrawal period compliance, use of antimicrobials for growth promotion, and the sustained use of critically important antimicrobials. Improved outreach and educational capacities, paired with increased veterinary resources and extensive monitoring in operations and retail meat products, may increase AMR awareness and policy enforcement.

Fecal Carriage and Molecular Epidemiology of Carbapenem-Resistant Enterobacteriaceae from Inpatient Children in a Pediatric Hospital of Shanghai

Purpose

To determine the epidemiology characteristics of intestinal colonization of carbapenem-resistant Enterobacteriaceae (CRE) among inpatients in a pediatric hospital in China.

Methods

A retrospective study was conducted from April to December 2019. Medical records were reviewed to extract the clinical information. Antimicrobial susceptibility was performed by broth microdilution method. Drug resistance determinants and plasmid types were analyzed using polymerase chain reaction (PCR) assays. Multilocus sequence typing (MLST) and Enterobacterial repetitive intergenic consensus sequences PCR (ERIC-PCR) were employed to determine the genetic relationships between strains.

Results

A total of 90 CRE strains were isolated, with a fecal carriage rate of 8.6% (90/1052), and mainly distributed in E. aerogenes (n=30), K. pneumoniae (n=25) and E. coli (n=23). More than 50% of CRE colonizers had a history of invasive procedures and antibiotic exposures. As high as 91.1% (82/90) of CRE isolates carried carbapenemase genes, with bla_NDM-5 (n=56) being the most common, and mainly found in E. aerogenes (51.8%, 29/56) and E. coli (32.1%, 18/56) isolates, which primarily belonged to ST4 (100%, 29/29) and ST692 (55.6%, 10/18), respectively. Followed by bla_KPC-2 (n=12), and all found in K. pneumoniae ST11 isolates. Other carbapenemase genes including bla_NDM-1, bla_IMP-4 and bla_IMP-26. Meanwhile, ESBL genes (bla_CTX-M, bla_TEM-1 and bla_SHV) and AmpC genes (bla_DHA-1 and bla_EBC) were also detected. All CRE isolates showed high resistance to cephalosporins and carbapenemases (97.8%-100.0%) but remained susceptible to tigecycline (98.9%). IncX3 was a major plasmid type in NDM-containing strains (91.3%), and 91.7% of KPC-2-producing K. pneumoniae harboring IncFII and IncFIB plasmids. The ERIC-PCR revealed that several strains with identical STs were genetically similar.

Conclusion

This study revealed a major intestinal colonization of ST4 NDM-5 E. aerogenes, ST11 KPC-2 K. pneumoniae and ST692 NDM-5 E. coli strains among inpatients in a pediatric hospital. Infection control measures should be implemented immediately to prevent the spread of these strains in clinical settings.

Genomic and Resistance Epidemiology of Gram-Negative Bacteria in Africa: a Systematic Review and Phylogenomic Analyses from a One Health Perspective

Antibiotic resistance (AR) is one of the major public health threats and challenges to effective containment and treatment of infectious bacterial diseases worldwide. Here, we used different methods to map out the geographical hot spots, sources, and evolutionary epidemiology of AR. Escherichia coli, Klebsiella pneumoniae, Salmonella enterica, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp., Neisseria meningitis/gonorrhoeae, Vibrio cholerae, Campylobacter jejuni, etc., were common pathogens shuttling AR genes in Africa. Transmission of the same clones/strains across countries and between animals, humans, plants, and the environment was observed. We recommend Enterobacter spp. or K. pneumoniae as better sentinel species for AR surveillance.

Antibiotic resistance (AR) remains a major threat to public and animal health globally. However, AR ramifications in developing countries are worsened by limited molecular diagnostics, expensive therapeutics, inadequate numbers of skilled clinicians and scientists, and unsanitary environments. The epidemiology of Gram-negative bacteria, their AR genes, and geographical distribution in Africa are described here. Data were extracted and analyzed from English-language articles published between 2015 and December 2019. The genomes and AR genes of the various species, obtained from the Pathosystems Resource Integration Center (PATRIC) and NCBI were analyzed phylogenetically using Randomized Axelerated Maximum Likelihood (RAxML) and annotated with Figtree. The geographic location of resistant clones/clades was mapped manually. Thirty species from 31 countries and 24 genera from 41 countries were analyzed from 146 articles and 3,028 genomes, respectively. Genes mediating resistance to β-lactams (including bla_TEM-1, bla_CTX-M, bla_NDM, bla_IMP, bla_VIM, and bla_OXA-48/181), fluoroquinolones (oqxAB, qnrA/B/D/S, gyrA/B, and parCE mutations, etc.), aminoglycosides (including armA and rmtC/F), sulfonamides (sul1/2/3), trimethoprim (dfrA), tetracycline [tet(A/B/C/D/G/O/M/39)], colistin (mcr-1), phenicols (catA/B, cmlA), and fosfomycin (fosA) were mostly found in Enterobacter spp. and Klebsiella pneumoniae, and also in Serratia marcescens, Escherichia coli, Salmonella enterica, Pseudomonas, Acinetobacter baumannii, etc., on mostly IncF-type, IncX_3/4, ColRNAI, and IncR plasmids, within IntI1 gene cassettes, insertion sequences, and transposons. Clonal and multiclonal outbreaks and dissemination of resistance genes across species and countries and between humans, animals, plants, and the environment were observed; Escherichia coli ST103, K. pneumoniae ST101, S. enterica ST1/2, and Vibrio cholerae ST69/515 were common strains. Most pathogens were of human origin, and zoonotic transmissions were relatively limited.

IMPORTANCE Antibiotic resistance (AR) is one of the major public health threats and challenges to effective containment and treatment of infectious bacterial diseases worldwide. Here, we used different methods to map out the geographical hot spots, sources, and evolutionary epidemiology of AR. Escherichia coli, Klebsiella pneumoniae, Salmonella enterica, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp., Neisseria meningitis/gonorrhoeae, Vibrio cholerae, Campylobacter jejuni, etc., were common pathogens shuttling AR genes in Africa. Transmission of the same clones/strains across countries and between animals, humans, plants, and the environment was observed. We recommend Enterobacter spp. or K. pneumoniae as better sentinel species for AR surveillance.

Molecular docking analysis of P2X7 receptor with the beta toxin from Clostridium perfringens

Clostridium perfringens beta-toxin (CPB) is linked to necrotic enteritis (over proliferation of bacteria) in several species showing cytotoxic effect on primary porcine endothelial and human precursor immune cells. P2X7 receptor on THP-1 cells is known to bind CPB. This is critical to understand the mechanism of pore formation for effective drug design. The structure of CPB and P2X7 receptor proteins were modeled using standard molecular modeling procedures (I-TASSER and Robetta server). This is followed by protein-protein docking (HADDOCK server) to study their molecular interaction. Interacting residues (19 residues from CPB and 21 residues from P2X7) were identified using the PISA server. Thus, we document the molecular docking analysis of P2X7 receptor with the beta toxin from Clostridium perfringens towards drug design and development of drugs to control necrotic enteritis.

Dissemination of Carbapenemases (KPC, NDM, OXA-48, IMP, and VIM) Among Carbapenem-Resistant Enterobacteriaceae Isolated From Adult and Children Patients in China

This study aimed to investigate the dissemination and characteristics of bla_KPC, bla_NDM, bla_OXA-48-like , bla_IMP, and bla_VIM among the carbapenem-resistant Enterobacteriaceae (CRE) strains isolated from adult and children patients. A total of 935 non-duplicate CRE strains were collected from 36 hospitals in 24 provinces or cities across China from 2016 to 2018. Antimicrobial susceptibility testing was performed by broth microdilution method and carbapenemase genes bla_KPC, bla_NDM, bla_OXA-48-like , bla_IMP, and bla_VIM were screened by PCR and confirmed by DNA sequencing. Overall, carbapenemases were produced in 97.4% (911/935) of CRE strains, including KPC-2 (51.6%, 482/935), NDM (35.7%, 334/935), and OXA-48-like carbapenemases (7.3%, 68/935). Overall, the most prevalent carbapenemase gene was bla_KPC-2 among Klebsiella pneumoniae (64.6%, 457/709) and the CRE strains isolated from adult patients (70.3%, 307/437), and bla_NDM among Escherichia coli (96.0%, 143/149) and the CRE strains from children (49.0%, 247/498). The bla_OXA-232-positive carbapenem-resistant K. pneumoniae (9.3%, 66/709) were all isolated from children. Sixteen strains were positive for bla_IMP and 9 strains produced multiple carbapenemases. No strain was positive for bla_VIM. Most of the CRE strains (>90%) were resistant to cephalosporins and carbapenems, more than half (>50%) were resistant to aminoglycosides and fluoroquinolones, but the majority (95.8 and 98.4%) were susceptible to polymyxin B and tigecycline. Ceftazidime-avibactam showed excellent in vitro activity against bla_KPC-2 and bla_OXA-48-like positive strains (100% susceptible). In China, KPC-2, NDM, and OXA-48-like carbapenemases were predominant among CRE clinical isolates. The most prevalent carbapenemase gene was bla_KPC-2 among K. pneumoniae isolates from adult patients, and bla_NDM among E. coli isolates from children.

Surveillance of Omadacycline Activity Tested against Clinical Isolates from the United States and Europe: Report from the SENTRY Antimicrobial Surveillance Program, 2016 to 2018

Omadacycline is a broad-spectrum aminomethylcycline approved in October 2018 by the U.S. Food and Drug Administration for treating acute bacterial skin and skin structure infections and community-acquired pneumonia as both an oral and intravenous once-daily formulation. In this report, the activities of omadacycline and comparators were tested against 49,000 nonduplicate bacterial isolates collected prospectively during 2016 to 2018 from medical centers in Europe (24,500 isolates, 40 medical centers [19 countries]) and the United States (24,500 isolates, 33 medical centers [23 states and all 9 U.S. census divisions]). Omadacycline was tested by broth microdilution following the methods in Clinical and Laboratory Standards Institute document M07 (Methods for Dilution Antimicrobial Susceptibility Tests for Bacteria That Grow Aerobically; Approved Standard, 11th ed., 2018). Omadacycline (MIC_50/90, 0.12/0.25 mg/liter) inhibited 98.6% of Staphylococcus aureus isolates at ≤0.5 mg/liter, including 96.3% of methicillin-resistant S. aureus isolates and 99.8% of methicillin-susceptible S. aureus isolates. Omadacycline potency was comparable for Streptococcus pneumoniae (MIC_50/90, 0.06/0.12 mg/liter), viridans group streptococci (MIC_50/90, 0.06/0.12 mg/liter), and beta-hemolytic streptococci (MIC_50/90, 0.12/0.25 mg/liter), regardless of species and susceptibility to penicillin, macrolides, or tetracycline. Omadacycline was active against all Enterobacterales tested (MIC_50/90, 1/8 mg/liter; 87.5% of isolates were inhibited at ≤4 mg/liter) except Proteus mirabilis (MIC_50/90, 16/>32 mg/liter) and indole-positive Proteus spp. (MIC_50/90, 8/32 mg/liter) and was most active against Escherichia coli (MIC_50/90, 0.5/2 mg/liter), Klebsiella oxytoca (MIC_50/90, 1/2 mg/liter), and Citrobacter spp. (MIC_50/90, 1/4 mg/liter). Omadacycline inhibited 92.4% of Enterobacter cloacae species complex and 88.5% of Klebsiella pneumoniae isolates at ≤4 mg/liter. Omadacycline was active against Haemophilus influenzae (MIC_50/90, 0.5/1 mg/liter), regardless of β-lactamase status, and against Moraxella catarrhalis (MIC_50/90, ≤0.12/0.25 mg/liter). The potent activity of omadacycline against Gram-positive and -negative bacteria indicates that omadacycline merits further study in serious infections in which multidrug resistance and mixed Gram-positive and Gram-negative bacterial infections may be a concern.

Mandatory surveillance and outbreaks reporting of the WHO priority pathogens for research & discovery of new antibiotics in European countries

OBJECTIVES

In 2017 the WHO published a global priority list of 12 antibiotic-resistant bacteria (ARB) in urgent need of new antibiotics. We aimed to identify and assess publicly accessible mandatory surveillance systems and outbreaks reporting for these pathogens in the 28 European Union and four European Free Trade Association member states.

METHODS

Compulsory reporting was mapped by reviewing national documents without applying language restrictions and through expert consultation. Information on surveillance targets, indicators, metrics and dissemination modalities was extracted and a qualitative assessment was performed for open access systems only.

RESULTS

Twenty-one countries (66%) had a mandate to survey at least one among the 12 WHO priority pathogens; 15 provided access to surveillance frameworks. These systems covered most frequently carbapenem-resistant Enterobacteriales (12; 38%), methicillin-resistant Staphylococcus aureus (12; 38%), and vancomycin-resistant enterococci (8; 25%). None of the European countries required reporting of resistance in Salmonella, Campylobacter, Helicobacter pylori and Neisseria gonorrhoeae. High heterogeneity was observed in data collection, reporting and dissemination among countries with clinical outcomes and risk factors being reported in less than half (22% and 25%). Only six countries (19%) implemented mandatory surveillance of outbreaks due to at least one WHO priority pathogen.

CONCLUSIONS

Our review shows that despite the increasing burden of ARB on the European population, very few countries implemented mandatory surveillance and outbreak reporting of the WHO priority pathogens. International efforts are needed to define the effectiveness of implementing mandatory reporting of these pathogens and to assess their role in reducing the spread of ARB in health-care and community settings.

Resurgence of pneumococcal meningitis in Europe and Northern America

BACKGROUND

Streptococcus pneumoniae is the most common pathogen causing bacterial meningitis. The routine use of multivalent conjugate pneumococcal vaccines has led to a decline of invasive pneumococcal disease caused by serotypes included in the vaccine serotypes. Recently, several reports have described a concomitant rise in the incidence of non-vaccine serotypes, suggesting serotype replacement.

OBJECTIVE

We aim to review the effect of pneumococcal vaccination on the incidence of pneumococcal meningitis in Europe and northern America with a particular interest in serotype replacement.

SOURCES

Articles that include data on invasive pneumococcal disease incidence before and after the introduction of vaccination, or on invasive pneumococcal serotype, are discussed, with a focus on pneumococcal meningitis.

CONTENT

The introduction of pneumococcal conjugate vaccines has universally resulted in a decline in vaccine-serotype pneumococcal meningitis incidence throughout Europe and northern America. Serotype replacement by non-vaccine serotypes has however been reported following the introduction of the 7-, 10- and 13-valent pneumococcal conjugate vaccines, which in several regions abolished the overall effect of vaccination on pneumococcal meningitis incidence.

IMPLICATIONS

The promising decline in the incidence of pneumococcal meningitis following the introduction of vaccination seems to have been temporary. Replacement by non-vaccine serotypes illustrates that pneumococcal meningitis continues to pose a major challenge. We need new approaches to prevention, new vaccines and continued efforts to improve treatment for patients with pneumococcal meningitis.

Satellite tracking of gulls and genomic characterization of faecal bacteria reveals environmentally mediated acquisition and dispersal of antimicrobial-resistant Escherichia coli on the Kenai Peninsula, Alaska

Gulls (Larus spp.) have frequently been reported to carry Escherichia coli exhibiting antimicrobial resistance (AMR E. coli); however, the pathways governing the acquisition and dispersal of such bacteria are not well described. We equipped 17 landfill-foraging gulls with satellite transmitters and collected gull faecal samples longitudinally from four locations on the Kenai Peninsula, Alaska to assess: (a) gull attendance and transitions between sites, (b) spatiotemporal prevalence of faecally shed AMR E. coli, and (c) genomic relatedness of AMR E. coli isolates among sites. We also sampled Pacific salmon (Oncorhynchus spp.) harvested as part of personal-use dipnet fisheries at two sites to assess potential contamination with AMR E. coli. Among our study sites, marked gulls most commonly occupied the lower Kenai River (61% of site locations) followed by the Soldotna landfill (11%), lower Kasilof River (5%) and upper Kenai River (<1%). Gulls primarily moved between the Soldotna landfill and the lower Kenai River (94% of transitions among sites), which were also the two locations with the highest prevalence of AMR E. coli. There was relatively high spatial and temporal variability in AMR E. coli prevalence in gull faeces and there was no evidence of contamination on salmon harvested in personal-use fisheries. We identified E. coli sequence types and AMR genes of clinical importance, with some isolates possessing genes associated with resistance to as many as eight antibiotic classes. Our findings suggest that gulls acquire AMR E. coli at habitats with anthropogenic inputs and subsequent movements may represent pathways through which AMR is dispersed.

Effects of laboratory capabilities on combating antimicrobial resistance, 2013-2016: A static model panel data analysis

OBJECTIVES

Antimicrobial resistance (AMR) has become a serious global public health problem. The World Health Organization (WHO) and European Union (EU) have taken actions to combat this issue, in which laboratory capability construction is a crucial part. This study aimed to explore the relationship between laboratory capabilities and antimicrobial resistance from a macro perspective.

METHODS

The study used annual national level penal data from the EU Laboratory Capability Monitoring System and Antimicrobial Resistance Surveillance Europe 2013-2016. A conventional static panel data analysis was constructed to establish the relationship between the antimicrobial resistance rates and laboratory capabilities.

RESULTS

Laboratory capability on antimicrobial drug resistance characterisation and monitoring (LC8) showed a positive effect on Escherichia coli (E. coli) combined resistance rate (Y5), E. coli resistant rate of aminoglycosides (Y4), and Klebsiella pneumoniae resistant rate of carbapenems (Y8) (OR=0.929, 0.957, and 0.861; P=0.035, 0.007, and 0.026, respectively). However, following the diagnostic testing guidelines (LC2) caused higher resistance rates of Klebsiella pneumoniae to fluoroquinolones (Y6), third-generation cephalosporins (Y7), and aminoglycosides (Y9) (OR=1.076, 1.093, and1.065; P=0.011, 0.032, and 0.002, respectively).

CONCLUSIONS

Antimicrobial drug resistance characterisation and monitoring by laboratories has contributed to minimising antimicrobial resistance, while the mechanism of laboratory capabilities to pose an ineffective or negative impact on AMR remains to be further studied.

Temporal and Geographic Variation in Antimicrobial Susceptibility and Resistance Patterns of Enterococci: Results From the SENTRY Antimicrobial Surveillance Program, 1997-2016

Background

The SENTRY Antimicrobial Surveillance Program was established in 1997 and presently encompasses more than 750 000 bacterial isolates from over 400 medical centers worldwide. Among these pathogens, enterococci represents a prominent cause of bloodstream (BSIs), intra-abdominal (IAIs), skin and skin structure, and urinary tract infections (UTIs). In the present study, we reviewed geographic and temporal trends in Enterococcus species and resistant phenotypes identified throughout the SENTRY Program.

Methods

From 1997 to 2016, a total of 49 491 clinically significant enterococci isolates (15 species) were submitted from 298 medical centers representing the Asia-Pacific (APAC), European, Latin American (LATAM), and North American (NA) regions. Bacteria were identified by standard algorithms and matrix-assisted laser desorption ionization–time of flight mass spectrometry. Susceptibility (S) testing was performed by reference broth microdilution methods and interpreted using Clinical and Laboratory Standards Institute/US Food and Drug Administration and European Committee on Antimicrobial Susceptibility Testing criteria.

Results

The most common Enterococcus species in all 4 regions were Enterococcus faecalis (64.7%) and E. faecium (EFM; 29.0%). Enterococci accounted for 10.7% of BSIs in NA and was most prominent as a cause of IAIs (24.0%) in APAC and of UTIs (19.8%) in LATAM. A steady decrease in the susceptibility to ampicillin and vancomycin was observed in all regions over the 20-year interval. Vancomycin-resistant enterococci (VRE) accounted for more than 8% of enterococcal isolates in all regions and was most common in NA (21.6%). Among the 7615 VRE isolates detected, 89.1% were the VanA phenotype (91.0% EFM) and 10.9% were VanB. Several newer antimicrobial agents demonstrated promising activity against VRE, including daptomycin (99.6–100.0% S), linezolid (98.0%–99.6% S), oritavancin (92.2%–98.3% S), tedizolid (99.5%–100.0% S), and tigecycline (99.4%–100.0% S).

Conclusions

Enterococci remained a prominent gram-positive pathogen in the SENTRY Program from 1997 through 2016. The overall frequency of VRE was 15.4% and increased over time in all monitored regions. Newly released agents with novel mechanisms of action show promising activity against VRE.

Twenty Years of the SENTRY Antifungal Surveillance Program: Results for Candida Species From 1997-2016

Background

The emergence of antifungal resistance threatens effective treatment of invasive fungal infection (IFI). Invasive candidiasis is the most common health care–associated IFI. We evaluated the activity of fluconazole (FLU) against 20 788 invasive isolates of Candida (37 species) collected from 135 medical centers in 39 countries (1997–2016). The activity of anidulafungin, caspofungin, and micafungin (MCF) was evaluated against 15 308 isolates worldwide (2006–2016).

Methods

Species identification was accomplished using phenotypic (1997–2001), genotypic, and proteomic methods (2006–2016). All isolates were tested using reference methods and clinical breakpoints published in the Clinical and Laboratory Standards Institute documents.

Results

A decrease in the isolation of Candida albicans and an increase in the isolation of Candida glabrata and Candida parapsilosis were observed over time. Candida glabrata was the most common non–C. albicans species detected in all geographic regions except for Latin America, where C. parapsilosis and Candida tropicalis were more common. Six Candida auris isolates were detected: 1 each in 2009, 2013, 2014, and 2015 and 2 in 2016; all were from nosocomial bloodstream infections and were FLU-resistant (R). The highest rates of FLU-R isolates were seen in C. glabrata from North America (NA; 10.6%) and in C. tropicalis from the Asia-Pacific region (9.2%). A steady increase in isolation of C. glabrata and resistance to FLU was detected over 20 years in the United States. Echinocandin-R (EC-R) ranged from 3.5% for C. glabrata to 0.1% for C. albicans and C. parapsilosis. Resistance to MCF was highest among C. glabrata (2.8%) and C. tropicalis (1.3%) from NA. Mutations on FKS hot spot (HS) regions were detected among 70 EC-R isolates (51/70 were C. glabrata). Most isolates harboring FKS HS mutations were resistant to 2 or more ECs.

Conclusions

EC-R and FLU-R remain uncommon among contemporary Candida isolates; however, a slow and steady emergence of resistance to both antifungal classes was observed in C. glabrata and C. tropicalis isolates.

Ceftobiprole activity when tested against contemporary bacteria causing bloodstream infections in the United States (2016-2017)

Ceftobiprole medocaril, the prodrug of ceftobiprole, is an advanced-generation cephalosporin that is approved in many European and non-European countries for the treatment of adults with hospital-acquired pneumonia (excluding ventilator-associated pneumonia) and community-acquired pneumonia and is currently being evaluated in a global phase 3 clinical trial of patients with Staphylococcus aureus bacteremia. This study investigated the in vitro activity of ceftobiprole and comparators against a total of 5466 gram-positive and -negative isolates from bloodstream infections (BSIs) that were collected in the United States during 2016 and 2017 as part of the SENTRY Antimicrobial Surveillance Program. Ceftobiprole was highly active (isolates were >99% susceptible) against S. aureus (including methicillin-resistant S. aureus), coagulase-negative staphylococci, Enterococcus faecalis, streptococci, and non-extended-spectrum β-lactamase (non-ESBL) phenotype Enterobacteriaceae. As expected, lower activities were observed against Enterococcus faecium, ESBL-phenotype Enterobacteriaceae, Pseudomonas aeruginosa, and Acinetobacter baumannii. These results support further clinical evaluation of ceftobiprole for the treatment of BSIs caused by susceptible organisms.

Antibiotic resistance trends of ESKAPE pathogens in Kwazulu-Natal, South Africa: A five-year retrospective analysis

Background

To combat antimicrobial resistance, the World Health Organization developed a global priority pathogen list of antibiotic-resistant bacteria for prioritisation of research and development of new, effective antibiotics.

Objective

This study describes a five-year resistance trend analysis of the ESKAPE pathogens: Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter spp., from Kwazulu-Natal, South Africa.

Methods

This retrospective study used National Health Laboratory Services data on 64 502 ESKAPE organisms isolated between 2011 and 2015. Susceptibility trends were ascertained from minimum inhibitory concentrations and interpreted using Clinical and Laboratory Standards Institute guidelines.

Results

S. aureus was most frequently isolated (n = 24, 495, 38%), followed by K. pneumoniae (n = 14, 282, 22%). Decreasing rates of methicillin-resistant S. aureus (28% to 18%, p < 0.001) and increasing rates of extended spectrum beta-lactamase producing K. pneumoniae (54% to 65% p < 0.001) were observed. Carbapenem resistance among K. pneumoniae and Enterobacter spp. was less than 6% during 2011–2014, but increased from 4% in 2014 to 16% in 2015 (p < 0.001) among K. pneumoniae. P. aeruginosa increased (p = 0.002), but resistance to anti-pseudomonal antimicrobials decreased from 2013 to 2015. High rates of multi-drug resistance were observed in A. baumanni (> 70%).

Conclusion

This study describes the magnitude of antimicrobial resistance in KwaZulu-Natal and provides a South African perspective on antimicrobial resistance in the global priority pathogen list, signalling the need for initiation or enhancement of antimicrobial stewardship and infection control measures locally.

Combined international external quality assessment results of medical laboratory performance and reporting of samples with known antimicrobial resistance

Background

Reporting on the presence of antimicrobial resistance is of considerable concern both for individual patient care and for understanding the underlying health status within the community at large. Antimicrobial resistance is solely dependent upon clinical laboratory detection and thus can be impacted upon by the quality and competence of medical laboratories. Proficiency testing or external quality assessment (PT/EQA) is the international standard for the direct measurement of medical laboratory performance on critical testing.

Methods

An international, intercontinental collaborative retrospective study of medical laboratory performance in antibiotic resistance was performed by the Microbiology Working Group (MWG) of the European Organisation for External Quality Assurance for Laboratory Medicine (EQALM) with particular examination of laboratory performance on the testing and reporting of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE) and carbapenem-resistant Enterobacteriaceae (CRE).

Results

The results of 1880 medical laboratories were compiled. Strictly accurate reporting of isolates as resistant occurred with MRSA 96.9%, with VRE 91.3% and with CRE 93.1% of the time. On the other hand, very major errors (reporting of false susceptibility) were observed with 2.2% of MRSA and 2.4% of VRE and 0.8% of CRE. Major errors (false resistance) were reported for vancomycin susceptibility testing for MRSA at a rate of 0.6%.

Conclusions

Depending on how clinical physicians read and understand microbiology susceptibility reports, proficient acceptable results were reported either between 91% and 94% of the time, or between 97% and 100%. While very major errors are infrequently reported, they were found in all regions and could potentially cause poor treatment decisions by clinicians. A collective analysis of multi-program PT/EQA information can provide valuable insights into the testing and reporting practices of medical laboratories.

Activity of omadacycline tested against Enterobacteriaceae causing urinary tract infections from a global surveillance program (2014)

Omadacycline is an aminomethylcycline with in vitro activity against many gram-negative pathogens. Omadacycline and comparators were tested against Enterobacteriaceae from urinary tract infections (UTIs) selected from a 2014 global surveillance program and compared to results of isolates from 2010 surveillance. The omadacycline MIC_50/90 for Enterobacteriaceae collected during 2014 was 2/≥8 μg/mL (1/4 μg/mL minus Proteus, Providencia, and Morganella spp.). The MIC_50/90 for E. coli was 1/2 μg/mL, similar to that in 2010 (MIC_50/90, 0.5/2 μg/mL). The MICs for 91.7% of Klebsiella spp. isolates in 2014 (89.7%, 2010) were ≤4 μg/mL. In 2010 and 2014, a total of 100.0% and 95.8% of ESBL screen-positive (SP) phenotype E. coli and 73.9% and 75.0% of ESBL SP Klebsiella spp., respectively, exhibited MIC values at ≤4 μg/mL. Omadacycline was active against UTI-causing Enterobacteriaceae isolates from NA and EU. Further study of omadacycline to treat UTIs caused by Enterobacteriaceae may be indicated.

Surveillance of tigecycline activity tested against clinical isolates from a global (North America, Europe, Latin America and Asia-Pacific) collection (2016)

Tigecycline and comparators were tested by the reference broth microdilution method against 33 348 non-duplicate bacterial isolates collected prospectively in 2016 from medical centres in the Asia-Pacific (3443 isolates), Europe (13 530 isolates), Latin America (3327 isolates) and the USA (13 048 isolates). Among 7098 Staphylococcus aureus isolates tested, >99.9% were inhibited by ≤0.5 mg/L tigecycline (MIC_50/90, 0.06/0.12 mg/L), including >99.9% of methicillin-resistant S. aureus and 100.0% of methicillin-susceptible S. aureus. Tigecycline was slightly more active against Enterococcus faecium (MIC_50/90, 0.03/0.06 mg/L) compared with Enterococcus faecalis (MIC_50/90, 0.06/0.12 mg/L) and its activity was not adversely affected by vancomycin resistance when tested against these organisms. Tigecycline potency was comparable for Streptococcus pneumoniae (MIC_50/90, 0.03/0.06 mg/L), viridans group streptococci (MIC_50/90, 0.03/0.06 mg/L) and β-haemolytic streptococci (MIC_50/90, 0.06/0.06 mg/L) regardless of species and penicillin susceptibility. Tigecycline was active against Enterobacteriaceae (MIC_50/90, 0.25/1 mg/L; 97.8% inhibited at ≤2 mg/L) but was slightly less active against Enterobacteriaceae isolates expressing resistant phenotypes: carbapenem-resistant Enterobacteriaceae (MIC_50/90, 0.5/2 mg/L; 98.0% susceptible); multidrug-resistant (MIC_50/90, 0.5/2 mg/L; 93.1% susceptible); and extensively drug-resistant (MIC_50/90, 0.5/4 mg/L; 87.8% susceptible). Tigecycline inhibited 74.4% of 888 Acinetobacter baumannii isolates at ≤2 mg/L (MIC_50/90, 2/4 mg/L) and demonstrated good in vitro activity against Stenotrophomonas maltophilia (MIC_50/90, 1/2 mg/L; 90.6% inhibited at ≤2 mg/L) Tigecycline was active against Haemophilus influenzae (MIC_50/90, 0.12/0.25 mg/L) regardless of β-lactamase status. Tigecycline represents an important treatment option for resistant Gram-negative and Gram-positive bacterial infections.

Antimicrobial activity of ceftobiprole and comparator agents when tested against contemporary Gram-positive and -negative organisms collected from Europe (2015)

Susceptibility testing of ceftobiprole and comparators against 12,240 isolates was performed following CLSI/EUCAST guidelines. The percentage of susceptible MRSA isolates was higher for ceftobiprole (96.5% susceptible) than for ceftaroline (86.2% susceptible). Both ceftobiprole (MIC_50/90, 0.5/2 mg/L) and ceftaroline (MIC_50/90, 0.25/1 mg/L) demonstrated potent activity against coagulase-negative staphylococci. Ceftobiprole demonstrated good potency against Enterococcus faecalis (MIC_50/90 values of 0.5/2 mg/L); ceftaroline (MIC_50/90, 2/8 mg/L) was 4-fold less active against these strains. Ceftobiprole activity was comparable to that of the other β-lactam agents tested against S. pneumoniae (MIC_90, 0.5 mg/L vs 0.12-2 mg/L [other β-lactams]), viridans-group streptococci (MIC₉₀,0.25 mg/L vs 0.006-1 mg/L [other β-lactams]), and β-hemolytic streptococci (MIC_90,0.03 mg/L vs 0.015-0.06 mg/L [other β-lactams]). Overall, 73.8% of Enterobacteriaceae isolates tested were susceptible to ceftobiprole. Ceftobiprole inhibited 70.4% of P. aeruginosa at ≤4 mg/L and all isolates of Haemophilus influenzae and Moraxella catarrhalis at ≤ 0.5 mg/L. Ceftobiprole was active in vitro against a broad range of clinically-relevant contemporary Gram-positive and Gram-negative bacterial isolates.

Ceftolozane-tazobactam activity against drug-resistant Enterobacteriaceae and Pseudomonas aeruginosa causing healthcare-associated infections in Latin America: report from an antimicrobial surveillance program (2013–2015)

This study evaluated the in vitro activity of ceftolozane-tazobactam and comparator agents tested against Latin American isolates of Enterobacteriaceae and Pseudomonas aeruginosa from patients with health care-associated infections. Ceftolozane-tazobactam is an antipseudomonal cephalosporin combined with a well-established β-lactamase inhibitor.

A total of 2415 Gram-negative organisms (537 P. aeruginosa and 1878 Enterobacteriaceae) were consecutively collected in 12 medical centers located in four Latin American countries. The organisms were tested for susceptibility by broth microdilution methods as described by the CLSI M07-A10 document and the results interpreted according to EUCAST and CLSI breakpoint criteria.

Results

Ceftolozane-tazobactam (MIC_50/90, 0.25/32 μg/mL; 84.2% susceptible) and meropenem (MIC_50/90, ≤0.06/0.12 μg/mL; 92.6% susceptible) were the most active compounds tested against Enterobacteriaceae. Among the Enterobacteriaceae isolates tested, 6.6% were carbapenem-resistant Enterobacteriaceae and 26.4% exhibited an extended-spectrum β-lactamase non-carbapenem-resistant phenotype. Whereas ceftolozane-tazobactam showed good activity against extended-spectrum beta-lactamase, non-carbapenem-resistant phenotype strains of Enterobacteriaceae (MIC_50/90, 0.5/>32 μg/mL), it lacked useful activity against strains with a (MIC_50/90, >32/>32 μg/mL; 1.6% S) carbapenem-resistant phenotype. Ceftolozane-tazobactam was the most potent (MIC_50//90, 0.5/16 μg/mL) β-lactam agent tested against P. aeruginosa isolates, inhibiting 86.8% at an MIC of ≤4 μg/mL. P. aeruginosa exhibited high rates of resistance to cefepime (16.0%), ceftazidime (23.6%), meropenem (28.3%), and piperacillin-tazobactam (16.4%).

Conclusions

Ceftolozane-tazobactam was the most active β-lactam agent tested against P. aeruginosa and demonstrated higher in vitro activity than available cephalosporins and piperacillin-tazobactam when tested against Enterobacteriaceae.

The 2016 Garrod Lecture: The role of the healthcare epidemiologist in antimicrobial chemotherapy-a view from the USA

Antimicrobial chemotherapy now spans 80 years and four generations. The healthcare epidemiologist has an important role to play in this field. Efforts focus in three areas: (i) minimizing the transmission of antimicrobial-resistant bacteria in healthcare settings (infection control); (ii) optimizing use of currently available antibacterial drugs (antibiotic stewardship); and (iii) recognizing and responding to opportunities for new drug development. For each area, the epidemiologist provides data that address four practical questions-'What is the problem?', 'What should be done?', 'Is it being done?' and 'Is it working?'. A team approach is crucial to acting on the epidemiological data. Examples are presented to illustrate different roles of the epidemiologist, and tools and measures that have been developed to address some problems of current importance. Monitoring of quality, integrity and security of data remains a major focus. The epidemiologist will continue to have a key role in antimicrobial chemotherapy.

Surveillance of Omadacycline Activity against Clinical Isolates from a Global Collection (North America, Europe, Latin America, Asia-Western Pacific), 2010-2011

Omadacycline is a broad-spectrum aminomethylcycline in late-stage clinical development for the treatment of acute bacterial skin and skin structure infections and community-acquired pneumonia as an oral and an intravenous once-daily formulation. In this study, omadacycline and comparators were tested against 69,246 nonduplicate bacterial isolates collected prospectively during 2010 and 2011 from medical centers in Asia-Pacific (11,397 isolates), Europe (23,490 isolates), Latin America (8,038 isolates), and North America (26,321 isolates). Omadacycline was tested by broth microdilution following Clinical and Laboratory Standards Institute M07-A10 (2015) methods. A total of 99.9% of Staphylococcus aureus isolates were inhibited by ≤2 μg/ml of omadacycline (MIC_50/90, 0.12/0.25 μg/ml), including 100.0% of methicillin-susceptible S. aureus isolates and 99.8% of methicillin-resistant S. aureus isolates. Omadacycline potencies were comparable for Streptococcus pneumoniae (MIC_50/90, 0.06/0.06 μg/ml), viridans group streptococci (MIC_50/90, 0.06/0.12 μg/ml), and beta-hemolytic streptococci (MIC_50/90, 0.06/0.12 μg/ml) regardless of species and susceptibility to penicillin. Omadacycline was active against Enterobacteriaceae and was most active against Escherichia coli (MIC_50/90, 0.5/2 μg/ml), Enterobacter aerogenes (MIC_50/90, 2/4 μg/ml), Klebsiella oxytoca (MIC_50/90, 1/4 μg/ml), and Citrobacter spp. (MIC_50/90, 1/4 μg/ml). Omadacycline was active against Haemophilus influenzae (MIC_50/90, 1/1 μg/ml) regardless of β-lactamase status and against Moraxella catarrhalis (MIC_50/90, 0.12/0.25 μg/ml). The potent activity of omadacycline against Gram-positive and Gram-negative bacteria indicates that omadacycline merits further study in serious infections in which multidrug resistance and mixed Gram-positive and Gram-negative infections may be a concern.

In Vitro Activity of Delafloxacin against Contemporary Bacterial Pathogens from the United States and Europe, 2014

The in vitro activities of delafloxacin and comparator antimicrobial agents against 6,485 bacterial isolates collected from medical centers in Europe and the United States in 2014 were tested. Delafloxacin was the most potent agent tested against methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus, Streptococcus pneumoniae, viridans group streptococci, and beta-hemolytic streptococci and had activity similar to that of ciprofloxacin and levofloxacin against certain members of the Enterobacteriaceae. Overall, the broadest coverage of the tested pathogens (Gram-positive cocci and Gram-negative bacilli) was observed with meropenem and tigecycline in both Europe and the United States. Delafloxacin was shown to be active against organisms that may be encountered in acute bacterial skin and skin structure infections, respiratory infections, and urinary tract infections.