Antibiotic resistance of culturable heterotrophic bacteria isolated from shrimp (Penaeus vannamei) aquaculture ponds

Shrimp aquaculture is one of the fastest growing food-producing avenues, where antibiotics usage has become an issue of great concern due to the development of antimicrobial resistance in bacteria. A total of 2304 bacterial isolates from 192 samples (sediment, water, shrimp, and source water) from Andhra Pradesh, India were screened. Antibiotic resistance of bacterial isolates was highest for oxytetracycline (23.4%) followed by erythromycin (12.7%), co-trimoxazole (10%) ciprofloxacin (9.6%), and chloramphenicol (6%), of which 11.9% isolates were multi-drug resistant. Bacterial isolates from shrimp (26.7%), water (23.9%), and sediment (19.6%) samples exhibited more resistance (p ≤ 0.05) towards oxytetracycline. Higher antibacterial resistance was observed from samples of southern Andhra Pradesh (locations L6 and L7). Gram negative bacteria were more prevalent (64%) and showed significantly (p ≤ 0.01) higher resistance. This study indicated the wider distribution of antibiotic-resistant bacteria in shrimp aquaculture ponds with potential risk to humans and the environment.

Evaluation of evidence-based urinalysis reflex to culture criteria: Impact on reducing antimicrobial usage

OBJECTIVES

To implement evidence-based urinalysis (UA) reflex criteria and to evaluate the impact of the intervention on reducing unnecessary antibiotic usage.

METHODS

A prospective intervention study was conducted on 4130 urine samples that were subjected to UA during March to May 2020. Results were analyzed in order to evaluate the effectiveness of newly implemented evidence-based criteria in predicting positive urine cultures. The intervention involved implementing evidence-based UA reflex criteria to ensure a high predictive value of the UA reflex parameters. Multivariable logistic regression was utilized to evaluate the effectiveness of these UA parameters in predicting positive urine cultures and to assess the impact of the new UA criteria on antibiotic usage.

RESULTS

A total of 4130 patient samples were included in the study; 60.1% (n = 2484) were from female patients and 39.9% (n = 1646) were from male patients. The total number of negative urine reflex samples was 3116, which accounted for 75.4% of the total UA reflex samples. In contrast, 24.6% of the urine reflex samples (n = 1014) returned positive UA results and were reflexed to urine culture. Among the urine samples that were cultured, 9% (n = 91) were negative urine cultures, while 91.0% (n = 923) were positive urine cultures. Chi-square analysis indicated highly statistically significant associations between the combination parameters of (≥5 white blood cells (WBCs) and positive nitrite) and positive urine cultures (Chi-square = 516.428, p < 0.001) and (≥5 WBCs and moderate or large esterase) and positive urine cultures (Chi-square = 503.387, p < 0.001). Additionally, Chi-square analysis indicated a highly statistically significant association between the combination parameters of (≥5 WBCs and ≥1 bacteria) and positive urine cultures (Chi-square = 434.806, p < 0.001). The statistical analysis showed that the implementation of evidence-based UA reflex criteria significantly decreased the number of urine cultures performed and potentially decreased the number of patients inappropriately treated with antibiotics from 45.1% to 9%.

CONCLUSIONS

In conclusion, ≥5 WBCs and positive nitrite yielded the highest positive predictive value of 98.00% and showed a highly significant association with positive urine cultures. It was observed that the new UA reflex criteria are highly effective in predicting positive urine cultures, thus potentially resulting in the reduction of unnecessary antibiotic usage.

Antimicrobial practices among small animal veterinarians in Greece: a survey

BACKGROUND

The inappropriate use of antibiotics is a major issue in clinical practice in Greece with serious implications for public health and animal health. The purpose of the present study was to provide a first insight into the use of antibiotics by small animal practitioners in Greece and assess their compliance with general rules for the rational use of antibiotics. This is the first survey of its kind in Greece.

METHODS

A questionnaire was designed to collect basic information on the use of antibiotics by pet veterinarians. The questionnaire was sent to a total of 70 veterinarians mainly operating in the region of Attica, a region that comprises almost 50% of the Greek population and where veterinarians are engaged solely in small animal practice. The questionnaire consisted of 37 closed questions dealing with various aspects on the use of antibiotics.

RESULTS

The majority of practitioners report cases where the pet owner initiated antibiotic treatment without veterinary prescription. Almost every clinician reported owner-compliance challenges. Regarding microbiological analysis, 73% of respondents initiate empirical treatment while waiting for laboratory results or use antibiogram only when the treatment is unsuccessful. Eighty-eight per cent declared to use antimicrobials postoperatively in clean surgical procedures. Different types of antimicrobials and treatment durations than the ones proposed by guidelines on rational use of antibiotics are preferred for various organ systems e.g. in urinary and gastrointestinal infections.

CONCLUSIONS

Our findings suggest the need for guidelines on antibiotic use in small animal practice in Greece, and the deployment of systematic surveillance on antimicrobials use and resistance to inform the initial choice of antibiotics upon local antimicrobial resistance profiles. Targeting the other end of the problem, pet owners, our findings indicate the need to educate them on the rational use of antibiotics and, critically, stop antibiotic availability without prescription.

Estimating the association between antibiotic exposure and colonization with extended-spectrum β-lactamase-producing Gram-negative bacteria using machine learning methods: a multicentre, prospective cohort study

OBJECTIVES

The aim of the study was to measure the impact of antibiotic exposure on the acquisition of colonization with extended-spectrum β-lactamase-producing Gram-negative bacteria (ESBL-GNB) accounting for individual- and group-level confounding using machine-learning methods.

METHODS

Patients hospitalized between September 2010 and June 2013 at six medical and six surgical wards in Italy, Serbia and Romania were screened for ESBL-GNB at hospital admission, discharge, antibiotic start, and after 3, 7, 15 and 30 days. Primary outcomes were the incidence rate and predictive factors of new ESBL-GNB colonization. Random forest algorithm was used to rank antibiotics according to the risk of selection of ESBL-GNB colonization in patients not colonized before starting antibiotics.

RESULTS

We screened 10 034 patients collecting 28 322 rectal swab samples. New ESBL-GNB colonization incidence with and without antibiotic treatment was 22/1000 and 9/1000 exposure-days, respectively. In the adjusted regression analyses, antibiotic exposure (hazard ratio (HR) 2.38; 95% CI 1.29-4.40), age 60-69 years (HR 1.19; 95% CI 1.05-1.34), and spring season (HR 1.25; 95% CI 1.14-1.38) were independently associated with new colonization. Monotherapy ranked higher als combination therapy in promoting ESBL-GNB colonization. Among monotherapy, cephalosporins ranked first followed by tetracycline (second), macrolide (fourth) and cotrimoxazole (seventh). Overall the ranking of cephalosporins was lower when used in combination. Among combinations not including cephalosporins, quinolones plus carbapenems ranked highest (eighth). Among sequential therapies, quinolones ranked highest (tenth) when prescribed within 30 days of therapy with cephalosporins.

CONCLUSIONS

Impact of antibiotics on selecting ESBL-GNB at intestinal level varies if used in monotherapy or combination and according to previous antibiotic exposure. These finding should be explored in future clinical trials on antibiotic stewardship interventions.

CLINICAL TRIAL REGISTRATION

NCT01208519.

Knowledge and awareness of the general public and perception of pharmacists about antibiotic resistance

Background

Antibiotic resistance (AR) continues to be a serious problem. Many factors contribute to AR, including inappropriate use of antibiotics, in which both healthcare professionals and patients play a contributing role. This study aimed to assess the awareness and knowledge of antibiotic usage and AR among the general public (in affluent and deprived areas) and community pharmacists’ (CPs’) in Greater London.

Methods

A cross-sectional survey involving members of the public was conducted between July 2014 and February 2015. Stage one involved members of the public (N = 384) residing in affluent areas of London. The second stage targeted public (N = 384) in deprived areas of London. In addition, CPs (N = 240) across the same areas were also surveyed. Data analysis was performed using Microsoft Excel and SPSS Software packages.

Results

Response rate: 36% (n = 139/384) and 57% (n = 220/384) and 25% (n = 60/240) of public residing in affluent areas, deprived areas and of CPs respectively was achieved. Definitive trends in knowledge of how antibiotics work could not be drawn to distinguish between affluent and deprived areas. However, public respondents residing in affluent areas possessed better understanding of AR and prudent use of antibiotics, and this was statistically significant in both cases (p < 0.05). Exposure to an antibiotic campaign (32% in affluent areas, 17% in deprived areas) did not raise public respondents’ knowledge on AR and only partially raised their general knowledge on antibiotics usage. Only 20% of public residing in deprived areas received counselling from a CP, among them 74% had an antibiotic prescribed on at least one previous occasion. Those who received counselling displayed better knowledge about concordance/adherence with respect to antibiotic usage (p < 0.05) whereas exposure to an antibiotic campaign made no significant impact on knowledge about concordance/adherence.

Conclusion

The study highlights that there has been no change in the status quo with respect to awareness of antibiotic usage and AR even after the implementation of several awareness campaigns in England. Those who benefited from CP counselling showed a significant better knowledge towards prudent antibiotic usage which stresses the importance of CPs’ counselling on antibiotic prescription.