The first discovered antibiotic was penicillin by the researcher Alexander Fleming, from a fungus, of the genus Penicillium, which its powerful bactericidal effect was and has been used against Gram+ bacteria. Later, semi-synthetic penicillin such as Ampicillin, Amoxicillin and Cloxacillin, the latter resistant to the “penicillinase” released by Staphylococcus aureus appeared. However, bacteria have developed survival mechanisms such as selection that allows them to infect the host cell and multi-resist antimicrobials , such as the case of Mycobacterium tuberculosis, Brucella abortus, Shigella dysenteriae, Listeria monicytogenes and Legionella pneumophila, all with high virulence for cattle. For example, Staphylococcus aureus, the main agent of clinical mastitis, is resistant to Penicillin, Tetracycline and Cephalexin .
On the other hand, the transfer of resistant pathogens to humans through the food chain, such as the consumption of meat and milk  , leads to the misuse of antibiotics in animals, hence, affecting the public health.
According to the European Antimicrobial Consumption Surveillance Office, Spain ranks fifth as a consumer of broad-spectrum penicillin. Besides being considered one of the countries with the highest rates of bacterial resistance and exporter of these resistances worldwide  .
There are very few works that explore the knowledge about the correct use of antibiotics in those in charge of Animal Health. Therefore, a measure to avoid the misuse of antibiotics is to assess the level of knowledge. In the present study, we conducted a questionnaire to collect information from Veterinary Medicine students and support the subsequent performance of a risk analysis in human health.
A cross-sectional descriptive observational study with an analytical component was carried out during 2019, in three groups of students (30 students per group) from the BSc in Veterinary Medicine and Zootechnics. The student’s knowledge about antibiotics was considered as the main variable. The structured survey consisted of ten questions that were elaborated as indicators of basic knowledge of the subject, carried out by the National Advisory Technical Council of Animal Health (Table 1). For the descriptive analysis of knowledge, four categories were considered: does not know insufficient knowledge, sufficient knowledge and optimal knowledge. For the data analysis, Microsoft Excel was used and the qualitative variables were expressed as percentages.
Of the 86 student surveys, the majority answered all questions. The results of the informative indicators note the student status in which 25% work in veterinary clinics (Figure 1). From their responses, it was observed that 63.14% of the students work in clinics and universities (Figure 2), 61.45% recognize that antibiotics
Table 1. Evaluated indicators in the survey in 2019.
Figure 1. Occupation from the sample population expressed in percentage.
Figure 2. Workplace from the sample population expressed in percentage.
Figure 3. Type of prescription needed according to the sample population expressed in percentage.
should be prescribed by quantified prescription, while 38.55% do not recognize it as requirement (Figure 3); 48.27% assure that the Veterinary Medicine intern can prescribe antimicrobials and 51.73% that a student cannot prescribe antimicrobials (Figure 4); 21.34% use antimicrobials for all microorganisms including viruses which implies an incorrect knowledge (Figure 5); 20% possess a poor knowledge about the use of antimicrobials in viral diseases (Figure 6); 18.60% use the labeling to consult the withdrawal time of antimicrobials (Figure 7) and 88.23% identify the withdrawal time of an antimicrobial and the practices as factors that lead to the development of resistance to antimicrobials (Figure 8). 20% of the students have a low knowledge about the withdrawal time that must be respected in antibiotics used for production animals (Figure 9).
Figure 4. Percentage of the sample population that believe whether a veterinarian can prescribe antimicrobials or not.
Figure 5. Percentage of the different microorganisms that can be treated by an antimicrobial according to the sample population.
Figure 6. Percentage of the sample population that believes antibacterial treatment can be used for viral diseases.
Figure 7. Most used means for withdrawal time expressed in percentage.
Figure 8. Practices that lead to antimicrobial resistance according to the sample population.
Figure 9. Withdrawal time in antibiotics used for production animals.
The strategies to identify the knowledge of Veterinary Medicine students about antimicrobials turns out to be a watershed that enables real information in the animal health sector that supports a risk analysis study for human population. One of the most surprising results obtained in the study was the fact of not knowing that antimicrobials are for the exclusive use of bacteria, as identified in students from China by . The authors exonerate the urgency of prioritizing education in health professionals. Hence, the areas of microbiology in the bachelor’s study plan as well as pharmacology should be reinforced. If we compare the efforts made in Human Medicine to identify their degree of knowledge in people , it can be noted the poor knowledge or ignorance from most of the sample population. In addition, the importance of the veterinarians in animal health and food safety is relevant, as mentioned by  . Currently there are advances to establish a rapid and safe diagnosis to identify the pathogenic agent of a disease. For example, molecular methods are available to detect resistance of bacteria to semi-synthetic penicillin, using the blaZ gene and ermC gene .
Therefore, an alternative solution to antimicrobial resistance of bacteria according to , are natural products. The antimicrobial properties of chemical compounds such as carvacrol, thymol, cineole, linalool, anethole, allicin, capsaicin, allyl isothiocyanate and piperine, have been obtained mainly from oregano, thyme, garlic, cloves, radish, chili, pepper, mint, cinnamon, anise, rosemary and sage 
The administration of antibiotics in production animals has several disadvantages, such as bacterial resistance, which makes disperse into human health. It is estimated that antibiotics will be restricted in most meat and milk importing countries by 2025. Meanwhile, the use of new therapies with products that are harmless to health and the environment should be foreseen. Such is the case of phytobiotics that have given good results as antibacterials.
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