PUBH6005 Assessment: Livestock Antibiotics and Superbug Development

This assignment is a critical appraisal essay focusing on the issue of antibiotic resistance and its link to livestock. The essay begins with an introduction to antibiotic resistance, the emergence of superbugs, and the overuse of antibiotics in both human and animal contexts, highlighting the role of livestock. The research question is: Is antibiotic usage for livestock the reason for the increased number of superbug emergence throughout the world? The methodology section outlines the search strategy used to identify five relevant research articles from databases such as Google Scholar, PubMed, CINAHL, and Medscape, and the application of the CASP tool for critical review. The results section presents the level of evidence for each article, followed by a detailed critical appraisal of each article using the CASP tool, assessing aspects such as the clarity of the research question, the relevance and validity of the research, and the applicability of the findings. The appraisal of each article is presented using a structured format, evaluating key parameters and providing responses that address the strengths and weaknesses of each study. The essay concludes by summarizing the key findings and discussing the implications of antibiotic usage in livestock for public health, emphasizing the need for further research and interventions to mitigate the risks of superbug emergence.

Running head: CRITICAL APPRAISAL ESSAY
CRITICAL APPRAISAL ESSAY
Name of the Student
Name of the University
Author note

1CRITICAL APPRAISAL ESSAY
Introduction
Antibiotics are the group of drugs which are used by physicians to treat several bacterial
infection (Young & Solomon, 2009). However, due to several genetic, and environmental factors
as well as physiological changes within the host, the bacteria evolves itself in such a way that
leads to change the response of the drug on it, leading to the emergence of antibiotic resistance
(Skelly, Dettori & Brodt, 2012). As this phenomenon is spreading in increasing pace throughout
the world, the world is facing tremendous problems associated with antibiotic resistance,
increasing emergence of superbug is the primary concern among these. There are several issues
such as proving the antibiotics without prescription for the animal as well as human use, not
completing the prescribed course and the increasing level of mutation within bacterial cells are
supreme among them. As per the report of World health organization (2015), in most part of the
world, overdose of antibiotics are provided without any proper supervision or and is consumed
by a large section of public for human and animal use (Bonita, Beaglehole & Kjellström, 2006).
Hence, the WHO indicated that the human civilization is again approaching the time when a
common disease can kill a person due to increased antibiotic resistance. In this assignment,
discussion about antibiotic resistance and its association with livestock and emergence of
superbugs will be discussed in the modern context. The GRADE Working Group (2004)
mentioned that in the United States of America, more than 80% of antibiotic produced are
utilized for the consumption of animals to make them disease free which increases the risk of
superbug emergence. Therefore, this assignment will try to comply the emergence of superbug
with utilization of antibiotics for livestock and for this purpose, will conduct a critical review
using five research articles (Rychetnick et al., 2002). The research question of this assessment

2CRITICAL APPRAISAL ESSAY
will be: Is antibiotic usage for livestock is the reason for the increased number of superbug
emergence throughout the world?
Method
While discussing the methodology, the search strategy utilized for identification of five
research articles used in the critical review for this assignment should be discussed (NHMRC,
2009). To find the research articles, different databases such as Google scholar, PubMed,
CINAHL, and Medscape was searched for livestock associated superbug mergence related
articles. The keywords, which were used for this purpose was ‘antibiotic resistance or resistance
to antibiotic medication and ‘livestock or animals’ and ‘emergence of superbug or increasing
amount of superbug’ and ‘antibiotic resistance and associated superbug emergence’. These key
terms were searched with different permutation and combinations throughout the four databases.
The exclusion criteria included articles where livestock was used as secondary subject and others
were the research was not completely based on animal use of antibiotics. This leads to refine the
search and from 31 different literatures, the five articles were chosen for this assessment. Further
the CASP tool was used for the review of all the five articles.
Results
The level of evidence for all the five articles are as follows:
Article no. Type of study Level of evidence Citation
1 Systematic Review
article
Level 1 (Fitzgerald, 2012)
2 Prospective study Level 1 (Nadimpalli et al.,
2015)

3CRITICAL APPRAISAL ESSAY
3 Sensitivity analysis
study
Level 1 (Zhu et al., 2013)
4 Cross sectional study Level 2 (Rinsky et al., 2013)
5 Prospective study Level 1 (Liu et al., 2013)
The critical appraisal of the articles using CASP tool is as follows:
Article 1
Parameters Response
Mention of a clearly focused question Yes, the systematic review included a clearly
focused question sit included a population for
the study, an intervention for the focused
question and the outcome was also included
in the review.
The authors included correct paper for the
review
The paper was able to include different
bacterial species found in the animals or
poultry which are being used for human
purposes and then used their finding sot
determine the research question.
All the relevant and important papers were
included in the study
The papers that were included in the study
were relevant to the research study and the
research question
The original papers included enough This cannot be determined as the researches

4CRITICAL APPRAISAL ESSAY
research to determine the assessment
question
that were included in the study were
completely focused on the staphylococcus
aureus and associated resistance in livestock
animals whereas, there are several other
bacterial strains are present that can become
resistant to the used antibiotic.
If the result of the review was combined, is
it appropriate?
No the result of the review was not combined,
there were 8 sections of the systematic review
and separate results were attached with all the
sections. Therefore, the result was not
appropriate as a combine result would have
able to prove the research question in a proper
way.
What is the result of the complete review? The result of the review was holistic as from
bovine animals to poultry, their host
specificity and their association with human
and livestock related infection was determine
din the review article.
Results are precise or not The results of the systematic review was
precise as all the papers which was included
in the study, determine the linkage between
antibiotic resistance and the effect of
livestock animals on the emergence of

5CRITICAL APPRAISAL ESSAY
superbugs.
Is it possible to apply the result on local
population?
This cannot be determined as in the lack of a
common result, the future application of the
study results cannot be assessed.
Each important outcome was given
importance
Yes, as associated with use of antibiotics for
animal purpose, this review was able to
discuss each animals associated with human
use and consumption so that emergence of
resistance and superbugs can be complied.
The harms and costs of the study was less
than the benefit of the review
As this was a review article, there were no
subject or experiment related harm that
occurred during the study and hence, the
portion of benefit was higher than harm or
cost.
Article 2
Parameters Response
Did the research address a clear and
focused issue?
Yes, it was clearly in the research aim and
objectives that the research wants to
determine the level of nasal carriage of

6CRITICAL APPRAISAL ESSAY
livestock-associated S. aureus among the
workers working in such facilities
The assignment of subject to treatment was
randomized or not
For this purpose, the research occurred with
industrial hog operation workers however, the
assignment of subjects for research groups
such as trail group and control group was
randomized.
All the subject that were included in the
study, accounted for its conclusion
As the study included all the working in such
environment and assessed them for specific
time limit, all the subject was responsible for
accounting to the conclusion.
Were all the subjects included in the
assessment were blind to the treatment?
Yes, the subjects were not informed about the
research study and after observational study,
they were assessed for detection of nasal
carriage of antibiotic resistant staphylococcus
aureus.
The groups were similar at the start of trial
or not
As the workers of the factory was included all
the study, no changes in the group was
noticed by the researchers while conducting

7CRITICAL APPRAISAL ESSAY
the study.
The groups were treated equally or not? Yes, all the groups included in the study were
treated equally other than research aspect but
on ethical ground so that the dignity of the
workers can be maintained.
The effect of the treatment lasted for how
long?
This cannot be determined form the study as
the primary aim of the research was to
determine the presence of antibiotic resistance
staphylococcus aureus in the body of the
workers working in the industrial hog
operation.
How correct the estimated effect was? The researchers already expected that due to
methicillin resistant staphylococcus aureus, al
the workers will have increased MRSA levels
and this estimation was correct.
Is the result found from the research is
applicable to local population
Yes, this is applicable to local population as
well as due to presence of the hog factory in
the environment, other people, who are away
from the factory also has the chances to
possess MRSA that could affect their

8CRITICAL APPRAISAL ESSAY
healthcare status.
The paper included all the clinically
important outcomes of the study
Yes, the paper included all the important
aspect of MRSA in the workers working in
factories where the animals are provided with
antibiotics to protect them for bacterial
infections.
The benefits worth the costs of the research
or not
The cost of the assessment was not associated
with the workers as they used to work in such
environment from a long time. Therefore, the
benefit of the research was much higher than
that of the cost or harm.
Article 3
Parameter Responses
Aim of the assignment was mentioned
clearly
Yes, the aim of the study was clearly
mentioned as the primary aim to to identify
any antibiotic resistant gene present on the
animal farms of China.
As the method of research is qualitative Yes, the research was qualitative as the high
capacity quantitative PCR was used to detect

9CRITICAL APPRAISAL ESSAY
the unique antibiotic resistant genes or ARGs
in the subjects.
Research design was proper and
determined the aim of the research
The researchers used the same method to
determine the presence of ARGs in the swine
farms throughout china and in this purpose
they assessed more than 10,000 animals.
Therefore the research process was
appropriate.
Was the requirement was appropriate to
the aim of research
As the research was able to meet the objective
of the study, the requirement was appropriate
to the aim of the research
The way of data collection helped to
address the research issue
As the data was collected after determination
of ARGs within the swine of farms, the data
collection was appropriate. and helped to
address the research issue
The relationship between subject and
researchers were mentioned properly
This cannot be determined as the subject of
the research was animals
Ethical issues were considered properly This also cannot be determined as there is no
mention of ethical consideration while
working with animals in the research paper.
The data analysis process was sufficient
and rigorous
Yes, the data analysis was rigorous as there is
a possibility of error while conducting the

10CRITICAL APPRAISAL ESSAY
research, therefore, the data analysis were
inclusive of bias and errors which should be
excluded.
The findings were clearly stated Yes, the findings were clearly stated that
Resistance gene diversity and abundance
patterns were identified after the completion
of the study.
the value of the research The value of the research is important as it
determined that monitored use of antibiotics
and metal for the disease prevention of
animals can be harmful for the human society.

11CRITICAL APPRAISAL ESSAY
Article 4
Parameters Response
Mention of a clearly focused question
within the study
Yes, the research article completely focused
the study on identification of industrial zones,
which are affected with methicillin resistant
staphylococcus aureus (MRSA).
Is the method used for research is able to
answer the research question?
The research method, cross sectional study
was able to determine the increasing risk of
MRSA in workers associated with industrial
livestock operations.
Selection of the subject is clearly described Yes, the subject selection was properly
described in the article.
The sampling process included bias or not The selection of the subjects had several
inclusion and exclusion criteria such as age,
ethnicity, lingual preferences that increased
the chances of bias as the workers having the
knowledge of English and Spanish were
chosen for the study.
Was the sample of the subjects were able to
refer to the population?
Yes, the sample size was able to refer to the
population as a huge amount of workers were
enrolled for the study.
The sample size was based on the pre study This cannot be determined as the research

12CRITICAL APPRAISAL ESSAY
statistical power article did not mentioned any pre study
statistical analysis of the topic.
Response rate was satisfactory The response rate of the workers was
satisfactory as they followed the instructions.
Measurements were reliable and valid Yes, it was valid and reliable. The researchers
depended on collection of swab for the
identification of MRSA within industrial
livestock operations and antibiotic-free
livestock operation workers.
Statistical significance was assessed Yes, the research calculated the statistical
significance of the results. the prevalence of
nasal carriages of staphylococcus aureus was
calculated for both the groups and also
calculated the link between demographic and
environmental factors to adjust the prevalence
ratio or PR.
The main results included confidence
intervals
Yes, the main result of the research study
included the 95% confidence interval.
Confounding factors were accounted or not No confounding factors were accounted in
this assessment more than the independent
variable
Results are applicable in future studies or Yes, the findings of this research are

13CRITICAL APPRAISAL ESSAY
not applicable for future studies as it indicated
towards the need of systematic national
surveillance for prevention of such
incidences.
Article 5
Parameters Responses
Did the research address a clear and
focused issue?
Yes, the research was able to focus on a clear
research question for the assessment.
The involvement of subject to treatment
was randomized or not
It is not clear from the research study that the
involvement of the subject in the process was
randomized as there were only two groups,
research group and the control group.
All the subject that were included in the
study, accounted for its conclusion
Yes, all the subject that were included in the
study, were responsible for it.
Were all the subjects included in the
assessment were blind to the treatment?
It is also not clear as the subject of the study
are animals.

14CRITICAL APPRAISAL ESSAY
The groups were similar at the start of trial
or not
Yes, all the animals that were included in the
study, observed for the entire trial.
The groups were treated equally or not? Yes, all the research and control groups
included in the study was treated equally.
The effect of the treatment lasted for how
long?
This cannot be determine as the aim of the
study was to identify the veterinary antibiotics
and antibiotic resistance gene residues in
swine wastewater.
How correct the estimated effect was? The estimated effect was completely correct
as the researchers were able to find the
antibiotic resistance gene in the host body
Is the result found from the research is
applicable to local population
Yes, the research results are applicable to the
local population of animals as the excessive
use of antibiotic resistance is effective.
The paper included all the clinically
important outcomes of the study
It cannot be determined from the assessment
as the research was able to find its primary
aim from the study
Discussion

15CRITICAL APPRAISAL ESSAY
All these articles were inclusive of the research question mentioned in this assignment,
however, several factors that included more in the study and should be termed as the highest
quality study. The study by Rinsky et al. (2013) was one of the high quality study as it was able
to directly mention the effect if proving livestock animals with antibiotic sin the emergence of
antibiotic resistance. It showed the emergence of antibiotic resistant bacteria in the nasal cavity
of ILO and AFLO exposed individuals. Besides these study by Nadimpalli et al. (2016) was also
high quality as it was able to establish the link between emergence of antibiotic resistant bacteria
and the workers working with such animals, who are provided with antibiotics. However, the
other papers were not being able to contribute completely to the section as their research was
focused on metals and genetic factors in creating antibiotic resistance in bacterial strains, such as
Zhu et al. (2013) discussed about ARG gene and metals in their study, limiting the research
question of this study. Whereas, the research gap for other literature was presence of different
factors such as pH and respective media that initiated the antibiotic resistance among the
bacterial strain. Therefore, these studies were not involved in the study.
Conclusion
While concluding, it should be mentioned that antibiotic resistance is the global concern
and the extensive uses of it without any proper prescription and knowledge is increasing its
deteriorating effects. In this assignment five articles associated with antibiotic resistance and its
association with livestock animals has been discussed. The five articles were from different
studies of research and hence a holistic approach to find the connection between these two
independent research variables were used in the study.

16CRITICAL APPRAISAL ESSAY
References
Bonita, R., Beaglehole, R., & Kjellström, T. (2006). Basic epidemiology. World Health
Organization.
Fitzgerald, J. R. (2012). Livestock-associated Staphylococcus aureus: origin, evolution and
public health threat. Trends in microbiology, 20(4), 192-198.
Liu, L., Liu, C., Zheng, J., Huang, X., Wang, Z., Liu, Y., & Zhu, G. (2013). Elimination of
veterinary antibiotics and antibiotic resistance genes from swine wastewater in the
vertical flow constructed wetlands. Chemosphere, 91(8), 1088-1093.
Nadimpalli, M., Rinsky, J. L., Wing, S., Hall, D., Stewart, J., Larsen, J., ... & Strelitz, J. (2015).
Persistence of livestock-associated antibiotic-resistant Staphylococcus aureus among
industrial hog operation workers in North Carolina over 14 days. Occup Environ
Med, 72(2), 90-99.
NHMRC (2009). NHMRC additional levels of evidence and grades for recommendations for
developers of guidelines. Retrieved from:
https://www.nhmrc.gov.au/_files_nhmrc/file/guidelines/developers/nhmrc_levels_grades
_evid ence_120423.pdf
Rinsky, J. L., Nadimpalli, M., Wing, S., Hall, D., Baron, D., Price, L. B., ... & Heaney, C. D.
(2013). Livestock-associated methicillin and multidrug resistant Staphylococcus aureus is
present among industrial, not antibiotic-free livestock operation workers in North
Carolina. PLoS One, 8(7), e67641.

17CRITICAL APPRAISAL ESSAY
Rychetnick, L., Frommer, M., Hawe, P., & Shiell, A. (2002). Criteria for evaluating evidence on
public health. Journal of Epidemiology and Community Health, 56, 119-127.
Skelly, A. C., Dettori J. R., & Brodt, E. K. (2012). Assessing bias: the importance of considering
confounding. Evidence Based Spine Care Journal, 3(1), 9-12
The GRADE Working Group (2004) Grading quality of evidence and strength of
recommendations. British Medical Journal. 328 1490-1494.
World Health Organization. (2015). Antibiotic resistance: Multi-country public awareness
survey.
Young, J.M., & Solomon, M.J. (2009). How to critically appraise an article. Nature Clinical
Practice Gastroenterology and Hepatology. 6, 82-91.
Zhu, Y. G., Johnson, T. A., Su, J. Q., Qiao, M., Guo, G. X., Stedtfeld, R. D., ... & Tiedje, J. M.
(2013). Diverse and abundant antibiotic resistance genes in Chinese swine
farms. Proceedings of the National Academy of Sciences, 201222743.