Impact of antimicrobial resistance on regulatory policies in veterinary medicine: status report

Complete genome sequencing of a Tequintavirus bacteriophage with a broad host range against Salmonella Abortus equi isolates from donkeys

Salmonella enterica subspecies enterica serovar abortus equi (S. Abortus equi) is the most common cause of abortion in mares. It has recently been found to cause abortion in donkeys more frequently in China. A novel virulent bacteriophage vB_SabS_Sds2 (hereafter designated as Sds2) was isolated from the feces of donkeys using a S. Abortus equi strain as a host. Phage Sds2 had an isometric polyhedral head and an uncontracted long tail, belonging to the Tequintavirus, Markadamsvirinae, Demerecviridae, Caudovirales. The genome of phage Sds2 was 114,770 bp, with a GC content of 40.26%. The genome contained 160 open reading frames (ORFs), and no ORFs were associated with pathogenicity, drug resistance, or lysogenization by sequence analysis. Both genome annotation and phylogenetic analysis indicated that phage Sds2 was highly similar to T5-like bacteriophages. Phage Sds2 could lyse 100% (30/30) of S. Abortus equi strains, 25.3% (24/95) of other serotypes of Salmonella strains, and 27.6% (8/29) of Escherichia coli strains using the double-layer agar plate method. The in vitro test showed that phage Sds2 had high bactericidal activity against S. Abortus equi at a wide range of MOIs. The in vivo test indicated that phage Sds2 had an inhibitory effect on abortion in mice challenged with S. Abortus equi. In general, phage Sds2 is a novel lytic phage with a wide host range and has the potential to prevent abortion caused by S. Abortus equi.

Evaluation of the broad-spectrum lytic capability of bacteriophage cocktails against various Salmonella serovars and their effects on weaned pigs infected with Salmonella Typhimurium

The broad-spectrum lytic capability of Salmonella bacteriophages against various Salmonella species was evaluated to determine their potential as an alternative for antibiotics, and the safety and preventive effects of the bacteriophages were assessed on mice and pigs. Four bacteriophage cocktails were prepared using 13 bacteriophages, and the lytic capability of the four bacteriophage cocktails was tested using Salmonella reference strains and field isolates. Bacteriophage cocktail C (SEP-1, SGP-1, STP-1, SS3eP-1, STP-2, SChP-1, SAP-1, SAP-2; ≥109 pfu/ml) showed the best lytic activity against the Salmonella reference strains (100% of 34) and field isolates (92.5% of 107). Fifty mice were then orally inoculated with bacteriophage cocktail C to determine the distribution of bacteriophages in various organs, blood and feces. The effects of bacteriophages on Salmonella infection in weaned pigs (n=15) were also evaluated through an experimental challenge with Salmonella Typhimurium after treatment with bacteriophage cocktail C. All mice exhibited distribution of the bacteriophages in all organs, blood and feces until 15 days post infection (dpi). After 35 dpi, bacteriophages were not detected in any of these specimens. As demonstrated in a pig challenge study, treatment with bacteriophage cocktail C reduced the level of Salmonella shedding in feces. The metagenomic analyses of these pig feces also revealed that bacteriophage treatment decreased the number of species of the Enterobacteriaceae family without significant disturbance to the normal fecal flora. This study showed that bacteriophages effectively controlled Salmonella in a pig challenge model and could be a good alternative for antibiotics to control Salmonella infection.

Antimicrobial residues and compositional quality of informally marketed raw cow milk, Lamu West Sub-County, Kenya, 2015

Introduction

unadulterated milk, free of antimicrobial residues is important for industrial processing and consumers’ health. Antimicrobial residues in foods of animal origin can cause adverse public health effects like drug resistance and hypersensitivity. Milk produced in Lamu West sub-county is sold raw directly to consumers. We estimated the compositional quality and prevalence of antimicrobial residues in informally marketed raw cow milk in Lamu West Sub-County, Kenya.

Methods

we randomly recruited 152 vendors and 207 farmers from four randomly selected urban centers in a cross-sectional study and interviewed them using a pretested standardized questionnaire. A100-ml raw milk sample was aseptically collected from each vendor and farm and tested for antimicrobial residues using Charm Blue Yellow II kit following the European Union Maximum Residue Limits (EU-MRLs) while an Ekomilk® Analyzer was used to measure compositional quality where samples with either solid not fat (SNF) < 8.5 or added water ≥ 0.01% or both were considered adulterated. We analyzed data using univariate analysis and unconditional logistic regression to calculate odds ratios (OR) and 95% confidence intervals (CI).

Results

thirty-two of the 207 (15.5%) samples from farmers and 28 (18.4%) of the 152 samples from vendors tested positive for antimicrobial residues. Thirty-six (17.4 %) samples from farmers and 38 (25.0%) from vendors were found to be adulterated with water. Farmers’ awareness of the danger of consuming milk with antimicrobial residues and farmers having training on good milking practices were protective against selling milk with antimicrobial residues (adjusted OR and 95% CI 0.20, 0.07-0.55 and 0.33, 0.11-0.99, respectively).

Conclusion

the antimicrobial residues above EU MRLs and adulteration of raw marketed cow milk observed in this study provide evidence for routine testing of marketed milk and educating farmers to observe antimicrobial withdrawal period.

Antibiotic use and resistance in animal farming: a quantitative and qualitative study on knowledge and practices among farmers in Khartoum, Sudan

Antibiotic resistance is a major emerging global public health threat. Farmers in the Khartoum state are believed to misuse antibiotics in animal farming leading to daily exposure to resistant bacteria and antibiotic residues. Hence, farmers are at potential risk exposure to bacteria, zoonotic infection and toxicity. We hypothesized that farmers' misuse of antibiotics could be due to their ignorance of the importance of optimal use of antibiotics, the potential health hazards and the economical waste associated with antibiotic misuse practices. In the present study, we investigated knowledge and practices among farmers regarding antibiotic use and resistance. For this purpose, a cross-sectional study was conducted in Khartoum state where data were collected from 81 farmers using structured interviews. Data were analysed both quantitatively and qualitatively. Fifty-two per cent of farmers were uneducated or had studied for < 6 years. The majority reported antibiotic use for treatment and prevention while only 5% stated use for growth promotion. Antibiotic group treatment for both sick and healthy animals was commonly practiced among most farmers. The most commonly used group of antibiotics was the quinolones, which was reported by one-third. Only 30% of the farmers had heard of antibiotic resistance and provided their definition. Almost half were not aware of the commonly transferred zoonotic infections between humans and animals. The farmers consume 1-2 meals/day from their own farm products. A significant association between low education, poor knowledge of farmers on antibiotic use, antibiotic resistance and zoonotic infections was found. This association may play a vital role in the present practiced misuse of antibiotics. Our findings on farmers' practices could be used as baseline information in defining the gaps related to antibiotic use and resistance in animal farming in Sudan. It can thus serve as a foundation for future interventions.

First characterization and emergence of SHV-60 in raw milk of a healthy cow in Japan

During monitoring of raw milk samples from healthy cows for the presence of antibiotic resistant bacteria, one isolate of Klebsiella pneumoniae strain HUF-100 was found to be resistant to oxyimino-cephalosporins and aztreonam. It was found to carry a chromosomally-encoded extended-spectrum beta-lactamase that has not been described previously, namely SHV-60. Thus, it must be expected that this strain will spread further among food-producing animals and thereby constitute a reservoir of this resistant strain and resistance gene that can transfer to and cause treatment problems for humans. The present study confirms the hypothesis that some of novel multiple antibiotic resistant zoonotic bacterial pathogens may initially emerge from food animals and reports, for the first time, this type of emergence in Japan.

Resistance to three antimicrobial agents of Campylobacter isolated from organically- and intensively-reared chickens purchased from retail outlets

Resistance rates to three antimicrobials (ciprofloxacin, erythromycin and nalidixic acid) in Campylobacter isolated from organically- and intensively-reared chickens purchased from supermarkets and butcher's shops in London were determined. Significant differences in the minimum inhibitory concentrations (MICs) of nalidixic acid were found, with the highest values in unpackaged intensively-reared chickens and the lowest values in organically-reared chickens. Using pre-set breakpoints, all isolates from all groups of chickens were identified as resistant to erythromycin and nalidixic acid. All isolates from the organically-reared group were susceptible to ciprofloxacin. Of the supermarket intensively-reared chickens, 8.7% harboured resistant isolates, all on the external parts, indicating post-slaughtering contamination. The highest percentage (26.7%) was in chickens from butcher shops, mostly in the chicken cavities, suggesting a link to treatment on the farm.

The Microbial Rosetta Stone Database: a compilation of global and emerging infectious microorganisms and bioterrorist threat agents

BACKGROUND

Thousands of different microorganisms affect the health, safety, and economic stability of populations. Many different medical and governmental organizations have created lists of the pathogenic microorganisms relevant to their missions; however, the nomenclature for biological agents on these lists and pathogens described in the literature is inexact. This ambiguity can be a significant block to effective communication among the diverse communities that must deal with epidemics or bioterrorist attacks.

RESULTS

We have developed a database known as the Microbial Rosetta Stone. The database relates microorganism names, taxonomic classifications, diseases, specific detection and treatment protocols, and relevant literature. The database structure facilitates linkage to public genomic databases. This paper focuses on the information in the database for pathogens that impact global public health, emerging infectious organisms, and bioterrorist threat agents.

CONCLUSION

The Microbial Rosetta Stone is available at http://www.microbialrosettastone.com/. The database provides public access to up-to-date taxonomic classifications of organisms that cause human diseases, improves the consistency of nomenclature in disease reporting, and provides useful links between different public genomic and public health databases.