Disease burden, associated mortality and economic impact of antimicrobial resistant infections in Australia

Tetracycline and chloramphenicol exposure induce decreased susceptibility to tigecycline and genetic alterations in AcrAB-TolC efflux pump regulators in Escherichia coli and Klebsiella pneumoniae

Tigecycline (Tgc), a third-generation tetracycline is found as the last line of defense against multi-drug resistant bacteria. Recent increased rate of resistance to tgc, a human-restricted agent among animal bacteria poses a significant global health challenge. Overuse of first generation tetracyclines (Tet) and phenicols in animals have been suggested to be associated with Tgc resistance development. In the current study we aimed to determine the effect of tetracycline (Tet) and chloramphenicol (Chl) overexposure on Tgc susceptibility. A Tet and Chl-susceptible isolate of K. pneumoniae and E. coli were exposed to successively increasing concentrations of tetracycline and chloramphenicol separately until a ≥4 times increase in Tet and Chl MICs was observed. Susceptibility changes to several antimicrobial agents were tested using disk diffusion and broth dilution methods. The genetic alterations of genes coding for major AcrAB regulators including acrR (repressor of acrAB), ramR (repressor of ramA), soxR (repressor of soxS) in K. pneumoniae and lon (proteolytic degradation of MarA), marR (repressor of marA), acrR and soxR in E. coli were investigated. The expression level of acrB was measured using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) method. The excessive exposure (15 to 40 selection cycles) of studied bacteria to both antibiotics significantly decreased susceptibility of Tet-resistant (R) and Chl-R variants of E. coli (n = 6) and K. pneumoniae (n = 6) to several groups of antibiotics including tigecycline (4-16 and 8-64 times respectively) and quinolones. About 58% of variants (n = 7) carried genetic alterations in AcrAB regulators including ramR (frameshift mutations/locus deletion), MarR (L33R, A70T, G15S amino acid substitutions) and Lon (L630F change, frameshift mutation) which were associated with acrB upregulation. Our study demonstrated the capacity of chloramphenicol and tetracycline exposure for selection of mutants which revealed tigecycline resistance/decreased susceptibility mostly mediated by active efflux mechanism. Unaltered acrB expression level in some strains indicates possible contribution of other efflux pumps or non-efflux-based mechanisms in the development of multiple- antibiotic resistance phenotype.

Emerging threats: Antimicrobial resistance in extended-spectrum beta-lactamase and carbapenem-resistant Escherichia coli

Antimicrobial resistance (AMR) in Escherichia coli strains, particularly those producing Extended-Spectrum Beta-Lactamase (ESBL) and Carbapenemase (CR-Ec), represents a serious global health threat. These resistant strains have been associated with increased morbidity, mortality, and healthcare costs, as they limit the effectiveness of standard antibiotic therapies. The prevalence of ESBL- and CR-Ec-producing strains continues to rise, driven by the overuse and misuse of antibiotics in healthcare and agricultural settings, and facilitated by global interconnectedness through international travel, trade, and food distribution. This review article examines the molecular mechanisms behind ESBL and CR resistance, focusing on the key genes involved in these processes, such as blaCTX-M, blaKPC, and blaNDM, and the clinical challenges posed by these strains. Additionally, the public health impact, including the spread of infections in hospital and community environments, is highlighted. The discussion emphasizes the urgent need for improved diagnostic tools, robust surveillance systems, and innovative therapeutic strategies. Emerging treatments, including phage therapy and novel antibiotic combinations, show promise in addressing these challenges and offer potential breakthroughs in combating resistant strains. Lastly, the review calls for stronger antimicrobial stewardship and policy reforms to mitigate the spread of resistant E. coli strains and protect global public health. Effective intervention at multiple levels, from diagnostics to policy, is critical to controlling the threat posed by AMR.

Prevalence and risk factors of antibiotic resistance for urinary tract infections in patients presenting to a Belgian tertiary care emergency department: testing the national guidelines against the local setting

OBJECTIVES

Urinary tract infections (UTIs) are an important cause of empiric antibiotic (over)treatment at the emergency department (ED). To enhance empiric antibiotic choices, mapping the national and local microbiology and antimicrobial resistance (AMR) patterns is crucial. This study aims to examine resistance patterns at a Brussels ED and to identify risk factors for AMR to evaluate current treatment guidelines and help combat AMR.

METHODS

Adult patients undergoing urinalysis at the ED of a Brussels tertiary care hospital with positive urine cultures were included. Descriptive microbiological mapping of UTI or asymptomatic bacteriuria (ASB) micro-organisms was performed. Potential risk factors of antibiotic resistance in Gram-negative bacteria were assessed by using logistic regression analysis.

RESULTS

Out of 96 patients with Gram-negative bacteria in urinary culture, the predominant uropathogen was Escherichia coli (58.3%), with 8.6% being extended spectrum beta-lactamase (ESBL)-producing strains. Overall, fosfomycin (29.2%) and nitrofurantoin (28.6%) showed the highest resistance rates. Ceftriaxone revealed lower resistance rates (13.1%) compared to ciprofloxacin (17.0%) and cefuroxime (18.4%). Temocillin exhibited the lowest resistance rate (8.2%) especially against ESBLs (0%). Ciprofloxacin resistance increased with age (OR 1.05 [1.01-1.10]) and recurrent UTIs (OR 4.79 [1.18-19.42]). Male gender was associated with higher odds of temocillin resistance (OR 5.79 [1.18-28.34]).

CONCLUSION

In the studied Belgian ED setting, ceftriaxone seems slightly safer than ciprofloxacin, especially for recurrent UTI patients. However, overall, and especially in patients at risk for ESBL-producing bacteria, temocillin would be an even better choice in our setting. National microbiological data should be reviewed to support recommending temocillin as a first-line antibiotic in patients presenting with upper UTI.

Molecular characteristics of CTX-M β-lactamase-producing and quinolone-resistant Escherichia coli among deer in a popular tourist spot in Japan

Introduction. Antimicrobial resistance (AMR) is a growing global concern. Clonal lineages of CTX-M β-lactamase-producing Escherichia coli (CTXE) and quinolone-resistant E. coli (QREC) were disseminated among the deer population in a famous tourist destination (Nara Park; NP) in Japan. Hypothesis/gap statement. The molecular characteristics of CTXE or QREC isolates, which could pose a threat to public health, have not been elucidated. Aim. This study aimed to characterize the genetic traits of CTXE and QREC isolates derived from NP deer and compare them with lineages prevalent worldwide. Methodology. Sixteen CTXE and three QREC isolates recovered from NP deer faeces between 2018 and 2020 were analysed using whole-genome sequencing (WGS). For endemic lineages, phylogenetic trees were constructed against the isolates registered in the EnteroBase database using the core genome SNP scheme. Results. The most prevalent lineage in NP deer was ST3580. Several pandemic lineages, such as sequence type (ST) 38, ST58 and ST117, were included. The QREC lineages prevalent among deer were designated as extra-intestinal pathogenic E. coli or uropathogenic E. coli (UPEC). Thirteen of the 24 antimicrobial resistance genes (ARGs) were considered high-risk ARG families. Chromosomal integration of bla CTX-M-15 was observed in all plasmid-negative isolates. Phylogenetic analysis suggested relationships between NP isolates and isolates sourced from the environment or poultry. Conclusion. ST3580 has a high potential for clonal dissemination. Furthermore, multiple clinically relevant lineages of CTXE and QREC are endemic in NP deer; however, they could be less virulent than isolates belonging to the same lineages, which could cause severe infectious diseases. Further studies are required to investigate the relationship between chromosomal integration of plasmid-encoded genes and the stable propagation of AMR bacteria in wildlife and the environment.

Antibiotic resistance: a global crisis, problems and solutions

Healthy state is priority in today's world which can be achieved using effective medicines. But due to overuse and misuse of antibiotics, a menace of resistance has increased in pathogenic microbes. World Health Organization (WHO) has announced ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) as the top priority pathogens as these have developed resistance against certain antibiotics. To combat such a global issue, it is utmost important to identify novel therapeutic strategies/agents as an alternate to such antibiotics. To name certain antibiotic adjuvants including: inhibitors of beta-lactamase, efflux pumps and permeabilizers for outer membrane can potentially solve the antibiotic resistance problems. In this regard, inhibitors of lytic domain of lytic transglycosylases provide a novel way to not only act as an alternate to antibiotics but also capable of restoring the efficiency of previously resistant antibiotics. Further, use of bacteriophages is another promising strategy to deal with antibiotic resistant pathogens. Taking in consideration the alternatives of antibiotics, a green synthesis nanoparticle-based therapy exemplifies a good option to combat microbial resistance. As horizontal gene transfer (HGT) in bacteria facilitates the evolution of new resistance strains, therefore identifying the mechanism of resistance and development of inhibitors against it can be a novel approach to combat such problems. In our perspective, host-directed therapy (HDT) represents another promising strategy in combating antimicrobial resistance (AMR). This approach involves targeting specific factors within host cells that pathogens rely on for their survival, either through replication or persistence. As many new drugs are under clinical trials it is advisable that more clinical data and antimicrobial stewardship programs should be conducted to fully assess the clinical efficacy and safety of new therapeutic agents.

Leveraging existing data to improve antimicrobial resistance-related mortality estimates for Australia

Antimicrobial resistance (AMR) is a global pandemic, however, estimating its burden is a complex process. As a result, many countries rely on global estimates to infer burden within their own setting. With a growing number of recent publications quantifying AMR burden in Australia, and an expansion of surveillance programs, enumerating AMR mortality for Australia is feasible. We aimed to leverage existing published data to assess methodological factors contributing to the considerable variation in AMR-related mortality and provide two reliable estimates of AMR mortality in Australia. This is a necessary step towards generating meaningful measures of AMR burden in Australia.

Human milk oligosaccharides regulate human macrophage polarization and activation in response to Staphylococcus aureus

Human milk oligosaccharides (HMOs) are present in high numbers in milk of lactating women. They are beneficial to gut health and the habitant microbiota, but less is known about their effect on cells from the immune system. In this study, we investigated the direct effect of three structurally different HMOs on human derived macrophages before challenge with Staphylococcus aureus (S. aureus). The study demonstrates that individual HMO structures potently affect the activation, differentiation and development of monocyte-derived macrophages in response to S. aureus. 6´-Sialyllactose (6'SL) had the most pronounced effect on the immune response against S. aureus, as illustrated by altered expression of macrophage surface markers, pointing towards an activated M1-like macrophage-phenotype. Similarly, 6'SL increased production of the pro-inflammatory cytokines TNF-α, IL-6, IL-8, IFN-γ and IL-1β, when exposing cells to 6'SL in combination with S. aureus compared with S. aureus alone. Interestingly, macrophages treated with 6'SL exhibited an altered proliferation profile and increased the production of the classic M1 transcription factor NF-κB. The HMOs also enhanced macrophage phagocytosis and uptake of S. aureus. Importantly, the different HMOs did not notably affect macrophage activation and differentiation without S. aureus exposure. Together, these findings show that HMOs can potently augment the immune response against S. aureus, without causing inflammatory activation in the absence of S. aureus, suggesting that HMOs assist the immune system in targeting important pathogens during early infancy.

Antimicrobial resistance in ocular infection: A review

Antimicrobial resistance (AMR) is a global public health threat with significant impact on treatment outcomes. The World Health Organization's Global Action Plan on AMR recommended strengthening the evidence base through surveillance programs and research. Comprehensive, timely data on AMR for organisms isolated from ocular infections are needed to guide treatment decisions and inform researchers and microbiologists of emerging trends. This article aims to provide an update on the development of AMR in ocular organisms, AMR in bacterial ocular infections and on AMR stewardship programs globally. The most common ocular pathogens are Pseudomonas aeruginosa, Staphylococcus spp., Streptococcus pneumoniae, and Haemophilus influenzae in ocular infections. A variety of studies and a few surveillance programs worldwide have reported on AMR in these infections over time. Fluoroquinolone resistance has increased particularly in Asia and North America. For conjunctivitis, the ARMOR cumulative study in the USA reported a slight decrease in resistance to ciprofloxacin. For keratitis, resistance to methicillin has remained stable for S. aureus and CoNS, while resistance to ciprofloxacin has decreased for MRSA globally. Methicillin-resistance and multidrug resistance are also emerging, requiring ongoing monitoring. Antimicrobial stewardship (AMS) programmes have a critical role in reducing the threat of AMR and improving treatment outcomes. To be successful AMS must be informed by up-to-date AMR surveillance data. As a profession it is timely for ophthalmology to act to prevent AMR leading to greater visual loss through supporting surveillance programmes and establishing AMS.

Deep Eutectic Solvent Eutectogels for Delivery of Broad-Spectrum Antimicrobials

Gel-based wound dressings have gained popularity within the healthcare industry for the prevention and treatment of bacterial and fungal infections. Gels based on deep eutectic solvents (DESs), known as eutectogels, provide a promising alternative to hydrogels as they are non-volatile and highly tunable and can solubilize therapeutic agents, including those insoluble in hydrogels. A choline chloride:glycerol-cellulose eutectogel was loaded with numerous antimicrobial agents including silver nanoparticles, black phosphorus nanoflakes, and commercially available pharmaceuticals (octenidine dihydrochloride, tetracycline hydrochloride, and fluconazole). The eutectogels caused >97% growth reduction in Gram-positive methicillin-resistant Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa bacteria and the fungal species Candida albicans.

Diversity of antimicrobial-resistant bacteria isolated from Australian chicken and pork meat

Antimicrobial-resistant bacteria are frequently isolated from retail meat and may infect humans. To determine the diversity of antimicrobial-resistant bacteria in Australian retail meat, bacteria were cultured on selective media from raw chicken (n = 244) and pork (n = 160) meat samples obtained from all four major supermarket chains in the ACT/NSW, Australia, between March and June 2021. Antimicrobial susceptibility testing (AST) was performed for 13 critically and 4 highly important antibiotics as categorised by the World Health Organization (WHO) for a wide range of species detected in the meat samples. A total of 288 isolates underwent whole-genome sequencing (WGS) to identify the presence of antimicrobial resistance (AMR) genes, virulence genes, and plasmids. AST testing revealed that 35/288 (12%) of the isolates were found to be multidrug-resistant (MDR). Using WGS data, 232/288 (81%) of the isolates were found to harbour resistance genes for critically or highly important antibiotics. This study reveals a greater diversity of AMR genes in bacteria isolated from retail meat in Australia than previous studies have shown, emphasising the importance of monitoring AMR in not only foodborne pathogenic bacteria, but other species that are capable of transferring AMR genes to pathogenic bacteria.

Reducing antibiotic prescribing in general practice in Australia: a cluster randomised controlled trial of a multimodal intervention

BACKGROUND

The health and economic burden of antimicrobial resistance (in Australia is significant. Interventions that help guide and improve appropriate prescribing for acute respiratory tract infections in the community represent an opportunity to slow the spread of resistant bacteria. Clinicians who work in primary care are potentially the most influential health care professionals to address the problem of antimicrobial resistance, because this is where most antibiotics are prescribed.

METHODS

A cluster randomised trial was conducted comparing two parallel groups of 27 urban general practices in Queensland, Australia: 13 intervention and 14 control practices, with 56 and 54 general practitioners (GPs), respectively. This study evaluated an integrated, multifaceted evidence-based package of interventions implemented over a 6-month period. The evaluation included quantitative and qualitative components, and an economic analysis.

RESULTS

A multimodal package of interventions resulted in a reduction of 3.81 prescriptions per GP per month. This equates to 1280.16 prescriptions for the 56GPs in the intervention practices over the 6-month period. The cost per prescription avoided was A$148. The qualitative feedback showed that the interventions were well received by the GPs and did not impact on consultation time. Providing GPs with a choice of tools might enhance their uptake and support for antimicrobial stewardship in the community.

CONCLUSIONS

A multimodal package of interventions to enhance rational prescribing of antibiotics is effective, feasible and acceptable in general practice. Investment in antimicrobial stewardship strategies in primary care may ultimately provide the important returns for public health into the future.

The two-component system WalKR provides an essential link between cell wall homeostasis and DNA replication in Staphylococcus aureus

IMPORTANCE

The opportunistic human pathogen Staphylococcus aureus uses an array of protein sensing systems called two-component systems (TCS) to sense environmental signals and adapt its physiology in response by regulating different genes. This sensory network is key to S. aureus versatility and success as a pathogen. Here, we reveal for the first time the full extent of the regulatory network of WalKR, the only staphylococcal TCS that is indispensable for survival under laboratory conditions. We found that WalKR is a master regulator of cell growth, coordinating the expression of genes from multiple, fundamental S. aureus cellular processes, including those involved in maintaining cell wall metabolism, protein biosynthesis, nucleotide metabolism, and the initiation of DNA replication.

Antimicrobial stewardship: knowledge, attitudes and practices regarding antimicrobial use and resistance among non-healthcare students at the University of Zambia

Background

Antimicrobial resistance (AMR) poses a significant threat to the world and could become humanity's next major challenge. This study assessed non-healthcare students' knowledge, attitude and practices (KAP) towards antimicrobial use (AMU) and AMR at the University of Zambia.

Methods

This cross-sectional study was conducted among 443 non-healthcare students from August to October 2022 using a structured questionnaire. Data analysis was done using IBM SPSS version 24.0.

Results

Of the 433 participants, 55.2%, 63.5% and 45% had moderate KAP scores regarding AMU and AMR. The prevalence of self-medication with antibiotics was 76.7%. Male participants were less likely to have good knowledge (OR = 0.524, 95% CI: 0.347-0.792) and positive attitudes (OR = 0.585, 95% CI: 0.364-0.940) towards AMU and AMR compared with females. Students who were studying Engineering and Mining were more likely to have good knowledge of AMR (OR = 1.891, 95% CI: 1.197-2.987) compared with those in Social Sciences. Those who were in their fourth and fifth years were more likely to have positive attitudes towards AMU and AMR (OR = 1.851, 95% CI: 1.147-2.986) compared with those who were in the first, second and third years. Finally, students who practised self-medication were less likely to have good self-reported practice towards AMR (OR = 0.442, 95% CI: 0.278-0.702) compared with those who did not.

Conclusions

This study demonstrated that non-healthcare students had moderate KAP regarding AMU and AMR. All university students should be provided with education about AMU and AMR through free short courses, seminars, workshops, and AMR and antimicrobial stewardship awareness campaigns.

Crisis averted: a world united against the menace of multiple drug-resistant superbugs -pioneering anti-AMR vaccines, RNA interference, nanomedicine, CRISPR-based antimicrobials, bacteriophage therapies, and clinical artificial intelligence strategies to safeguard global antimicrobial arsenal

The efficacy of antibiotics and other antimicrobial agents in combating bacterial infections faces a grave peril in the form of antimicrobial resistance (AMR), an exceedingly pressing global health issue. The emergence and dissemination of drug-resistant bacteria can be attributed to the rampant overuse and misuse of antibiotics, leading to dire consequences such as organ failure and sepsis. Beyond the realm of individual health, the pervasive specter of AMR casts its ominous shadow upon the economy and society at large, resulting in protracted hospital stays, elevated medical expenditures, and diminished productivity, with particularly dire consequences for vulnerable populations. It is abundantly clear that addressing this ominous threat necessitates a concerted international endeavor encompassing the optimization of antibiotic deployment, the pursuit of novel antimicrobial compounds and therapeutic strategies, the enhancement of surveillance and monitoring of resistant bacterial strains, and the assurance of universal access to efficacious treatments. In the ongoing struggle against this encroaching menace, phage-based therapies, strategically tailored to combat AMR, offer a formidable line of defense. Furthermore, an alluring pathway forward for the development of vaccines lies in the utilization of virus-like particles (VLPs), which have demonstrated their remarkable capacity to elicit a robust immune response against bacterial infections. VLP-based vaccinations, characterized by their absence of genetic material and non-infectious nature, present a markedly safer and more stable alternative to conventional immunization protocols. Encouragingly, preclinical investigations have yielded promising results in the development of VLP vaccines targeting pivotal bacteria implicated in the AMR crisis, including Salmonella, Escherichia coli, and Clostridium difficile. Notwithstanding the undeniable potential of VLP vaccines, formidable challenges persist, including the identification of suitable bacterial markers for vaccination and the formidable prospect of bacterial pathogens evolving mechanisms to thwart the immune response. Nonetheless, the prospect of VLP-based vaccines holds great promise in the relentless fight against AMR, underscoring the need for sustained research and development endeavors. In the quest to marshal more potent defenses against AMR and to pave the way for visionary innovations, cutting-edge techniques that incorporate RNA interference, nanomedicine, and the integration of artificial intelligence are currently under rigorous scrutiny.

Antibiotic resistance in wastewater: Indian scenario

The surge of Antibiotic Resistant Bacteria (ARB) in the environment is poised to be the next health threat. World Health Organisation's (WHO's) Global Antimicrobial Surveillance System (GLASS) report indicates that developing countries may be at a greater risk. Among various factors, the major driver here could be untreated wastewater and poor sanitation. Bacteria are extremely adaptable to their surroundings and develop Antimicrobial Resistance (AMR) when exposed to antibiotics and other pollutants that cause microbial stress. Thus, untreated domestic wastewater drains could easily become hotspots for the occurrence of ARBs. This study reports surveillance of sewage-carrying drains across four urban cities in India and demonstrated the presence of ARBs in the bacterial community against 7 classes of antibiotics, namely, β-Lactams, Chloramphenicol, Glycopeptides, Macrolides, Tetracycline, Third Generation Cephalosporin, and Quinolones. Untreated domestic wastewater flowing in target drains was collected twice a month, for a period of six months and the microbial community was subjected to Antibiotic Susceptibility Testing (AST) by plate assays. The zone of inhibition was recorded and interpreted as per the interpretive chart of The Clinical & Laboratory Standards Institute (CLSI) & The European Committee on Antimicrobial Susceptibility Testing (EUCAST). The total number of samples showing resistance against antibiotics was used to define an Antibiotic Resistance Index (ARI), calculated for all 20 sampling sites (drains). Results demonstrated that the highest ARI was observed in Delhi and Mumbai, ranging from 0.81 to 0.92 in Delhi and 0.49-0.56 in Mumbai. This surveillance study reveals the antibiotic resistance pattern of the representative bacterial community in the drains and goes beyond few targeted bacterial species. The alarming presence of antibiotic resistant bacterial community highlights the concern of ARBs being the next looming health threat. This report aims to demonstrates the importance of considering sewage surveillance on routine basis by state authorities.

Exploring the Preferences of the Australian Public for Antibiotic Treatments: A Discrete Choice Experiment

OBJECTIVES

Identify Australian public preferences for antibiotic treatments in the context of antibiotic stewardship.

METHODS

A discrete choice experiment (DCE) was conducted in Australia to investigate the importance of seven attributes associated with antibiotic treatments and related stewardship practices: contribution to antimicrobial resistance (AMR), treatment duration, side effects, days needed to recover, days before taking antibiotics, treatment failure and out-of-pocket costs. The DCE data were analysed using conditional logit, mixed logit and latent class conditional logit models. The relative importance of each attribute was calculated.

RESULTS

A total of 1882 respondents completed the survey; the main study sample consist of 1658 respondents (mean age 48 years) who passed quality checks. All seven attributes significantly influenced respondents' preferences for antibiotic treatments. Based on the designed attribute levels in the DCE, on average, out-of-pocket costs (32.8%) and contribution to antibiotic resistance (30.3%) were the most important attributes, followed by side effects (12.9%). Days before starting medication was least important (3.9%). Three latent classes were identified. Class 1 (including respondents who were more likely to be older and more health literate; 24.5%) gave contribution to antibiotic resistance greater importance in treatment preferences. Class 2 (including respondents more likely to report poorer health; 25.2%) gave out-of-pocket costs greater importance. The remaining (50.4%), who were generally healthier, perceived side effects as the most important attribute.

CONCLUSIONS

Despite concerted public awareness raising campaigns, our results suggest that several factors may influence the preferences of Australians when considering antibiotic use. However, for those more likely to be aware of the need to preserve antibiotics, out-of-pocket costs and limiting the contribution to antibiotic resistance are the dominant influence. Delays in starting treatment were not important for any latent class, suggesting public tolerance for this measure. These results could help inform strategies to promote prudent antibiotic stewardship.

Antimicrobial Resistance Patterns and Risk Factors Associated with ESBL-Producing and MDR Escherichia coli in Hospital and Environmental Settings in Lusaka, Zambia: Implications for One Health, Antimicrobial Stewardship and Surveillance Systems

Antimicrobial resistance (AMR) is a public health problem threatening human, animal, and environmental safety. This study assessed the AMR profiles and risk factors associated with Escherichia coli in hospital and environmental settings in Lusaka, Zambia. This cross-sectional study was conducted from April 2022 to August 2022 using 980 samples collected from clinical and environmental settings. Antimicrobial susceptibility testing was conducted using BD PhoenixTM 100. The data were analysed using SPSS version 26.0. Of the 980 samples, 51% were from environmental sources. Overall, 64.5% of the samples tested positive for E. coli, of which 52.5% were from clinical sources. Additionally, 31.8% were ESBL, of which 70.1% were clinical isolates. Of the 632 isolates, 48.3% were MDR. Most clinical isolates were resistant to ampicillin (83.4%), sulfamethoxazole/trimethoprim (73.8%), and ciprofloxacin (65.7%) while all environmental isolates were resistant to sulfamethoxazole/trimethoprim (100%) and some were resistant to levofloxacin (30.6%). The drivers of MDR in the tested isolates included pus (AOR = 4.6, CI: 1.9-11.3), male sex (AOR = 2.1, CI: 1.2-3.9), and water (AOR = 2.6, CI: 1.2-5.8). This study found that E. coli isolates were resistant to common antibiotics used in humans. The presence of MDR isolates is a public health concern and calls for vigorous infection prevention measures and surveillance to reduce AMR and its burdens.

Identifying and Prioritising Behaviours to Slow Antimicrobial Resistance

As a nation with relatively low levels of AMR, due to both community and agricultural stewardship, as well as geographical isolation, Australia is somewhat unique. As this advantage is being eroded, this project aimed to investigate the spectrum of human behaviours that could be modified in order to slow the spread of AMR, building upon the argument that doable actions are the best-targeted and least complex to change. We conducted a workshop with a panel of diverse interdisciplinary AMR experts (from sociology, microbiology, agriculture, veterinary medicine, health and government) and identified twelve behaviours that, if undertaken by the public, would slow the spread of AMR. These were then assessed by a representative sample of the public (285 Australians) for current participation, likelihood of future participation (likelihood) and perceived benefits that could occur if undertaken (perceived impact). An impact-likelihood matrix was used to identify four priority behaviours: do not pressure your doctor for antibiotics; contact council to find out where you can safely dispose of cleaning products with antimicrobial marketing; lobby supermarkets to only sell antibiotic free meat products; and return unused antibiotics to a pharmacy. Among a multitude of behavioural options, this study also highlights the importance of tailoring doable actions to local conditions, increasing community education, and emphasizing the lack of a one-size fits all approach to tackling this global threat.

The effect of Lactobacillus with prebiotics on KPC-2-producing Klebsiella pneumoniae

Objectives

This study investigated the inhibitory effect of Lactobacillus spp. with prebiotics against Klebsiella pneumoniae carbapenemase-2 (KPC-2)-producing Klebsiella pneumoniae using both in vitro experiments and animal models.

Methods

Thirty-three Lactobacillus spp. strains were confirmed by 16S rDNA sequencing, and four different PFGE genotyped KPC-2-producing K. pneumoniae strains were selected for investigation. In vitro studies, including broth microdilution assays, changes in pH values in lactobacilli cultures with different prebiotics, time-kill tests of Lactobacillus spp. against KPC-2-producing K. pneumoniae and further in vivo Lactobacillus alone or in combination with prebiotics against KPC-2-producing K. pneumoniae in an animal model, were performed.

Results

The lower pH value of the cell-free supernatant was associated with a lower minimal inhibitory percentage of the Lactobacillus strain against KPC-2-producing K. pneumoniae. Furthermore, lactulose/isomalto-oligosaccharide/inulin and fructo-oligosaccharide can enhance the inhibitory effect of all 10⁷ CFU/ml Lactobacillus strains against KPC001. Three Lactobacillus strains (LYC1154, LYC1322, and LYC1511) that could be persistently detected in the stool were tested for their ability to reduce the amount of KPC001 in the feces individually or in combination. A significantly better effect in reducing the amount of KPC001 was observed for the combination of three different Lactobacillus species than for each of them alone. Furthermore, their inhibitory effect was enhanced after adding lactulose or isomalto-oligosaccharide (both p < 0.05).

Conclusion

This study demonstrates the inhibitory effect of probiotic Lactobacillus, including LYC1154, LYC1322, and LYC1511, with prebiotics such as lactulose or isomalto-oligosaccharide against the colonization of KPC-2-producing K. pneumoniae.