Quantifying trade-offs between therapeutic efficacy and resistance dissemination for enrofloxacin dose regimens in cattle.

The use of antimicrobial drugs in food-producing animals increases the selection pressure on pathogenic and commensal bacteria to become resistant. This study aims to evaluate the existence of trade-offs between treatment effectiveness, cost, and the dissemination of resistance in gut commensal bacteria. We developed a within-host ordinary differential equation model to track the dynamics of antimicrobial drug concentrations and bacterial populations in the site of infection (lung) and the gut. The model was parameterized to represent enrofloxacin treatment for bovine respiratory disease (BRD) caused by Pastereulla multocida in cattle. Three approved enrofloxacin dosing regimens were compared for their effects on resistance on P. multocida and commensal E. coli: 12.5 mg/kg and 7.5 mg/kg as a single dose, and 5 mg/kg as three doses. Additionally, we explored non-approved regimes. Our results indicated that both 12.5 mg/kg and 7.5 mg/kg as a single dose scenario increased the most the treatment costs and prevalence of P. multocida resistance in the lungs, while 5 mg/kg as three doses increased resistance in commensal E. coli bacteria in the gut the most out of the approved scenarios. A proposed scenario (7.5 mg/kg, two doses 24 hours apart) showed low economic costs, minimal P. multocida, and moderate effects on resistant E. coli. Overall, the scenarios that decrease P. multocida, including resistant P. multocida did not coincide with the scenarios that decrease resistant E. coli the most, suggesting a trade-off between both outcomes. The sensitivity analysis indicates that bacterial populations were the most sensitive to drug conversion factors into plasma (ß), elimination of the drug from the colon (υ), fifty percent sensitive bacteria (P. multocida) killing effect (Ls50), fifty percent of bacteria (E. coli) above ECOFF killing effect (Cr50), and net drug transfer rate in the lung (γ) parameters.

Early evaluation of the Food and Drug Administration (FDA) guidance on antimicrobial use in food animals on antimicrobial resistance trends reported by the National Antimicrobial Resistance Monitoring System (2012-2019).

Antimicrobial resistance (AMR) is one of the biggest challenges to global public health. To address this issue in the US, governmental agencies have implemented system-wide guidance frameworks and recommendations aimed at reducing antimicrobial use. In particular, the Food and Drug Administration (FDA) prohibited the extra-label use of cephalosporins in food animals in 2012 and issued the guidance for industry (GFI) #213 about establishing a framework to phase out the use of all medically relevant drugs for growth promotion in 2012. Also in 2015, the FDA implemented veterinary feed directive (VFD) drug regulations (GFI# 120) to control the use of certain antimicrobials. To assess the potential early effects of these FDA actions and other concurrent antimicrobial stewardship actions on AMR in the food chain, we compared the patterns of the phenotypic (minimum inhibitory concentration (MIC) and percentage of resistance) and genotypic resistances for selected antimicrobials before and after 2016 across different enteric pathogen species, as reported by the National Antimicrobial Resistance Monitoring System (NARMS). Most of the antimicrobials analyzed at the phenotypic level followed a downward trend in MIC after implementing the guidance. Although, most of those changes were less than one 1-fold dilution. On the other hand, compared to MIC results, the results based on phenotypic resistance prevalence evidenced higher differences in both directions between the pre- and post-guidance implementation period. Also, we did not find relevant differences in the presence of AMR genes between pre- and post-VFD drug regulations. We concluded that the FDA guidance on antimicrobial use has not led to substantial reductions in antimicrobial drug resistance yet.

Sero-prevalence and risk factors associated with brucellosis in dairy cattle of Sylhet District, Bangladesh: A cross-sectional study.

BACKGROUND: Brucellosis is an emerging disease that causes a significant impact on productive and reproductive performance in dairy cattle. Though Brucella is a pivotal microorganism for dairy cattle, the scenario of brucellosis in Sylhet District is unknown. OBJECTIVES: A cross-sectional study was carried out to assess the prevalence and determinants associated with brucellosis in dairy cattle of Sylhet District. METHODS: A total of 386 sera and data on determinants from 63 dairy herds were collected from 12 sub-districts using simple random sampling. The sera were tested with Rose Bengal Brucella antigen test, Brucella abortus plate agglutination test and serum agglutination test to find out the sero-positivity. RESULTS: Overall, 17.09% (95% CI: 13.67-21.18) prevalence in cows were calculated. Relatively higher prevalence (56.08%; 95% CI: 42.23-70.32) was recorded in cows having parity ≥4 and were at higher risk (OR = 7.28) than the other cows with parity 0-3. Prevalence was significantly higher in cows with history of abortion 90.63% (95% CI: 75.79-96.76), repeat breeding 79.17% (95% CI: 65.74-88.27) and reproductive abnormalities 48.54% (95% CI: 39.12-58.07). Farm-level prevalence was high in farms with the previous history of abortion 95.45% (95% CI: 78.20-99.19) and repeat breeding 90.00% (95% CI: 74.38-96.54). CONCLUSIONS: The prevalence was high in Sylhet district, which might be a public health concern. Therefore, this study would represent the baseline information for guiding brucellosis control and prevention.

Antibiotic Prescribing Practices for Upper Respiratory Tract Infections Among Primary Care Providers: A Descriptive Study.

Background: Most antibiotics are prescribed in the ambulatory setting with estimates that up to 50% of use is inappropriate. Understanding factors associated with antibiotic misuse is essential to advancing better stewardship in this setting. We sought to assess the frequency of unnecessary antibiotic use for upper respiratory infections (URIs) among primary care providers and identify patient and provider characteristics associated with misuse. Methods: Unnecessary antibiotic prescribing was assessed in a descriptive study by using adults ≥18 years seen for common URIs in a large, Upper Midwest, integrated health system, electronic medical records from June 2017 through May 2018. Individual provider rates of unnecessary prescribing were compared for primary care providers practicing in the departments of internal medicine, family medicine, or urgent care. Patient and provider characteristics associated with unnecessary prescribing were identified with a logistic regression model. Results: A total of 49 463 patient encounters were included. Overall, antibiotics were prescribed unnecessarily for 42.2% (95% confidence interval [CI], 41.7-42.6) of the encounters. Patients with acute bronchitis received unnecessary antibiotics most frequently (74.2%; 95% CI, 73.4-75.0). Males and older patients were more likely to have an unnecessary antibiotic prescription. Provider characteristics associated with higher rates of unnecessary prescribing included being in a rural practice, having more years in practice, and being in higher volume practices such as an urgent care setting. Fifteen percent of providers accounted for half of all unnecessary antibiotic prescriptions. Conclusions: Although higher-volume practices, a rural setting, or longer time in practice were predictors, unnecessary prescribing was common among all providers.

Epidemiology of Hepatitis C virus infection among incarcerated populations in North Dakota.

This retrospective cohort study was conducted to determine the prevalence of HCV infections among individuals incarcerated in a state prison system and identify potential contributing factors to HCV infection. North Dakota Department of Corrections and Rehabilitation (NDDOCR) data from 2009 to 2018 was used and period prevalence was calculated for this 10-year time period. The period prevalence of HCV infection was (15.13% (95% CI 14.39-15.90) with a marginally significant (p-value: 0.0542) increasing linear trend in annual prevalence over this period. Multivariate logistic regression analysis was used to identify risk factors associated with HCV infection. The main significant independent risk factors for HCV infection in this incarcerated population were age >40 years [OR: 1.78 (1.37-2.32)]; sex [OR: 1.21 (1.03-1.43)]; race/ethnicity [OR: 1.97 (1.69-2.29)]; history of intravenous drug use (IVDU) [OR: 7.36 (6.41-8.44)]; history of needle or syringe sharing [OR: 7.57 (6.62-8.67)]; and alcohol use [OR: 0.87 (0.77-0.99)]. Study limitations include uncollected information on sexual history, frequency or duration of injection drug use and blood transfusion history of the incarcerated population. Considering the high prevalence of HCV infection and its associated risk factors, it is important to implement prevention programs such as syringe/needle exchanges and counsel with imprisoned IVD users.

Prevalence of Eimeria spp. with associated risk factors in dairy calves in Sylhet, Bangladesh.

BACKGROUND: Bovine eimeriosis is thought to be very important for the productivity and health of cattle all over the world. Despite the importance of cattle farming in Sylhet, little is known about the prevalence of bovine Eimeria spp. and the risk factors connected with it. OBJECTIVES: We conducted a study to evaluate the prevalence, species diversity and associated risk factors of Eimeria spp. in a population of 50 cattle farms from 12 upazilas (sub-district) in Sylhet district. METHODS: Faecal samples were collected randomly from a total of 554 calves ranging in age from 1 month to 2 years old during a period of 7 months. We used Flotation and McMaster techniques for parasitological examination. Species identification was done by using their morphological and morphometric characteristics. RESULTS: Out of 554 calves, 308 were found to be positive for Eimeria species (55.60%). Seven species of Eimeria were identified. Among the identified species, E. bovis (38.98%), E. zuernii (26.17%) and E. alabamensis (22.38%) were found to be the most prevalent species. Mixed and species-specific Eimeria infection were (24.73%; 95% CI 21.32-28.49) and (30.87%; 95% CI 27.17-34.84), respectively. In addition, the highest prevalence was observed at Zakigonj (68%; 95% CI 58.34-76.33) and the lowest at Companygonj (40%; 95% CI 30.94-49.80). Eimeria species intensity ranged between 50 and 76,550 oocyst per gram of faeces. Analysis of associated risk factors by using multivariate logistic regression analysis revealed that age, gender and body condition were significantly (p < 0.05) associated with Eimeria infection. CONCLUSIONS: Based on these present findings, it can be assumed that 'coccidia belong to the most prevalent pathogens in the population of calves in the study area'. Thus, the findings of this study could be used as tools for adoptive surveillance and effective control and prevention of the disease in cattle populations in this region.

Prevalence and antimicrobial susceptibility profiles of non-typhoidal Salmonella isolated from chickens in Rajshahi, Bangladesh.

Salmonellosis in poultry is an important disease that seriously impedes the development of the poultry industry. The increased resistance to antimicrobials against Salmonella has been a major public health concern worldwide. We conducted a study from January to June 2016 in and around the Rajshahi district of Bangladesh on the commercial chicken to isolate, identify and characterize poultry-specific Salmonella, to assess the potential risk factors and to determine the antimicrobial resistance pattern of the isolates. The overall prevalence of Salmonella enterica was 41% (49/120) [95% CI: 31.95%-50.17%] with 41.7% in broiler chicken (25/60) [95% CI: 29.06%-55.12%] and 40% in layer chicken (24/60, 40%) [95% CI: 27.56%-53.46%]. Samples collected from Rajshahi city (OR = 1.37, 95% CI: 0.50-3.73) and Puthia Upazila (OR = 1.51, 95% CI: 0.56-4.12) were more likely to be positive for Salmonella than Charghat Upazila. Salmonella detection was 1.3 times higher in chicken, providing loose feed than those provided ready feed. All the isolates fermented dextrose, maltose and mannitol with the production of acid and gas, but did not ferment sucrose and lactose. The isolates showed catalase, MR, citrate utilization test and TSI agar test positive, but indole and V-P tests negative. Salmonella isolates were sensitive to ciprofloxacin (90%), gentamycin (80%), amoxicillin (75%), streptomycin (70%), ampicillin (45%) and sulfamethoxazole-trimethoprim (45%), whereas highly resistant to penicillin (100%) and nalidixic acid (100%) followed by sulfamethoxazole-trimethoprim (55%), ampicillin (40%) and amoxicillin (25%). Salmonella enterica is endemic in commercial chicken production in Bangladesh with high prevalence. A considerable proportion of Salmonella isolates was found to be resistant to the majority of the common antimicrobial drugs. A good biosecurity system could be effective for the reduction of Salmonella. It is necessary to obtain universal commitments to establish prudent antibiotic use policies.