Prevalence of multidrug resistant livestock associated staphylococcus aureus isolated from nasal passage of healthy cattle

Project Abstract

Livestock-associated Staphylococcus aureus (LA-SA) is a significant concern due to its potential to cause infections in both animals and humans. This study aimed to investigate the prevalence of multidrug-resistant LA-SA strains isolated from the nasal passages of healthy cattle. Nasal swab samples were collected from 300 healthy cattle in different farms, and Staphylococcus aureus strains were isolated and identified using standard microbiological techniques. Antimicrobial susceptibility testing was performed using the disk diffusion method according to CLSI guidelines. Additionally, the presence of mecA gene, responsible for methicillin resistance, was determined using PCR. The results revealed that 35% of the sampled cattle were carriers of Staphylococcus aureus in their nasal passages, with 60% of these isolates classified as LA-SA. Furthermore, 45% of the LA-SA isolates were found to be multidrug-resistant, displaying resistance to three or more classes of antibiotics commonly used in both veterinary and human medicine. The most common resistances observed were against tetracycline, penicillin, and erythromycin. PCR analysis confirmed the presence of the mecA gene in 70% of the multidrug-resistant LA-SA isolates, indicating the prevalence of methicillin-resistant strains among the cattle. The study highlights the substantial prevalence of multidrug-resistant LA-SA strains among healthy cattle, suggesting a potential risk for transmission to humans through direct contact or consumption of contaminated animal products. The findings underscore the importance of monitoring and controlling antimicrobial use in livestock farming to mitigate the emergence and spread of resistant strains. Furthermore, implementing stringent biosecurity measures and promoting good hygiene practices among farmers and veterinary personnel are crucial to prevent the dissemination of multidrug-resistant LA-SA in both animal and human populations. In conclusion, this research provides valuable insights into the prevalence of multidrug-resistant LA-SA in healthy cattle, emphasizing the need for continuous surveillance and intervention strategies to address antimicrobial resistance in the livestock sector. Efforts to reduce the carriage and transmission of resistant strains among animals can contribute to safeguarding animal health, food safety, and public health.

Project Overview

<p> </p><p><strong>INTRODUCTION</strong></p><p><strong>1.1 Background to the Study</strong></p><p>Cattle are large bodied ruminants that feed on pastures and forages or fodder. In Nigeria, cattle are reared primarily for meat which is a veritable source of protein for humans, and for milk (Arowolo <em>et al</em>., 2013). Cattle rearing in Nigeria is an old occupation which is traditionally practiced by Fulanis and Shuwa Arabs in northern Nigeria with an extremely few local villages in the southern Nigeria (Erebor, 2003).</p><p><em>Staphylococcus aureus </em>is a facultative anaerobic gram-positive coccal bacterium and due to a combination of numerous bacteria immune-evasive strategies which it uses, it is considered a successful pathogen. The nasal passages is considered to be the major habitat (Kluytmans <em>et al</em>., 1997; Lowy, 1998; Lowy, 2003) and the biggest supply of <em>S. aureus</em>&nbsp;in people, yet numerous body locales can harbor this bacterium (Vandenbergh &amp; Verbrugh, 1999). <em>S. aureus</em>&nbsp;is a typical tenant of the skin (Lowy, 2003; Williams, 1963), perineum and can likewise be found in the axillae (Ridley, 1959), vagina (Guinan <em>et al</em>., 1982) and the gastrointestinal tract (Williams, 1963). <em>S. aureus</em>&nbsp;strains are noteworthy human pathogens and are conceivably ready in contaminating any human body tissue, bringing on everything from skin contaminations to life-debilitating sicknesses. In people, the diseases brought on by <em>S. aureus</em>&nbsp;can be partitioned into these three sorts in general; shallow sores, (for example, surgical site and wound contaminations), life and systemic undermining factors, (for example, osteomyelitis, endocarditis, pneumonia, mind abscesses/wounds, bacteraemia and meningitis), then toxinoses, (for example, poisonous stun disorder, sustenance harming and singed skin disorder (Alo <em>et al</em>., 2013; Aires de Sousa <em>et al</em>., 2004; Lowy, 2003). The sign of staphylococcal contamination are the boils that contain discharge which is made up of dead neutrophils, dead and living microbes, tissue (necrotic), the lysed host substance and bacterial cells. The immunocompetent hosts, as a rule, effectively clear the disease and deplete the ulcer, though for the immunocompromised and sporadically for a sound individual, the contamination might advance to a more profound tissues and turn into a conceivably lethal intrusive contamination (Norvick, 2006). It is still one of the five most common causes of nososcomial infections, often causing postsurgical wound infections (Bowersox, 1999). <em>S. aureus</em>&nbsp;is likewise known to colonize and contaminate both pets and animals, including pooches, felines, rabbits, stallions, steers and pigs (Morgan, 2008). A noteworthy concern is the nearness of methicillin safe <em>S. aureus</em>&nbsp;(MRSA) in pets and domesticated animals, as these may fill in as repositories for human colonization, an illustration is MRSA ST398 from pigs (Weese, 2010).</p><p>The unneces<em>sar</em>y utilization of antibiotics has prompted to the rise of different medication safe strains of <em>S.aureus</em>&nbsp;(Lowy, 1998). The Penicillin was presented for curing infections caused by <em>S. aureus</em>&nbsp;in the 1940s, and adequately diminished mortality and bleakness. Be that as it may, in late 1940s, its resistance because of the nearness of penicillinase developed (Eickhoff, 1972). The staphylococci are extremely fit for advancing imperviousness to the regularly utilized antimicrobials, for example, erythromycin (Walmark &amp; Finland, 1961), ampicillin (Klein and Finland, 1963), and antibiotic medication (Eickhoff, 1972). Much of the time, imperviousness to antimicrobial agents is coded for by qualities carried on plasmids, representing the quick spread of resistant microscopic organisms (Morris <em>et al</em>., 1998). One purpose behind the proceeding with essential part of <em>S. aureus</em>&nbsp;in illness is its inclination and propensity to wind up distinctly impervious to antimicrobial (Waldvogel, 2000). <em>S. aureus</em>&nbsp;is presently the main general reason for nosocomial diseases and, as more patients are dealt with outside the healing center setting, is an expanding worry in the group (CDC NNIS System, 2001; Diekema, 2001).</p><p>The time of medication development and its execution in human and creature wellbeing and horticulture was started by the revelation of anti-infection agents over 70 years prior. These disclosures were powerful against organisms consequently were viewed as effective against pathogenic microorganisms however this achievement was fleeting as they were tempered with in all cases by the rise of resistant microorganisms (D’Costa <em>et al</em>., 2011). A standout amongst the most relentless issues confronted by human services benefits far and wide is the expanding pervasiveness of antimicrobial resistance. This resistance is broadly perceived as a noteworthy general wellbeing danger and this issue is aggravated by a consistent reducing of the quantity of new specialists (antimicrobials) entering the clinical practice (D.H, 2000). There is an expanding worry that some less-alarming infections which were effortlessly treated are currently turning out to be progressively hard to treat and ailments created by microscopic organisms which are impervious to antimicrobial agents may set aside a more drawn out time of opportunity to treat successfully (Butler <em>et al</em>., 2006). In spite of the fact that the issue of multidrug resistance has pulled in the consideration of medicinal services administrations and the overall population, rates of antimicrobial resistance among healing center and group pathogens have expanded alarmingly amid the previous decade (NNIS, 2001).</p><p><strong>1.2 Statement of the Problem</strong></p><p>In Nigeria, cattle are reared primarily as a source of meat. According to Kuehnert <em>et al</em>. (2006), Lowy (1998, 2003), Onanuga &amp; Temedie (2011), Vandenbergh &amp; Verbrugh<strong>&nbsp;(</strong>1999), Williams (1963), the nares and the skin of humans and animals may be considered as ecological niche for <em>S. aureus</em>&nbsp;colonization but this colonization does not frequently result into infection thereby tagging the bacterium a normal flora of these body parts. <em>S. aureus </em>colonizes the nares and the skin but if there is an abrasion, lesion or wound in these parts, <em>S. aureus </em>may migrate into the body or blood and cause infections. These infections are called opportunistic (staphylococcal) infections. Compared to other pathogens, <em>S. aureus</em>&nbsp;has a high tendency and proneness to become resistant to antimicrobials (Weese, 2010). This fact, coupled with the constant abuse of drugs and lack of control in the sales of antibiotics contributes to the increasing problem in multidrug resistance of <em>S. aureus</em>&nbsp;including methicillin and vancomycin which is considered as the first line of treatment against methicillin resistant <em>Staphylococcus aureus</em>&nbsp;(MRSA). Cuny <em>et al</em>. (2015), Fluit (2012), Johnson (2011) and Morgan (2008) established that methicillin resistant <em>S. aureus </em>(a multidrug resistant organism) may not only be a nosocomial and community acquired infection but it could also be a zoonotic infection as it can be transmitted from animal to human. The presence of multidrug resistant <em>S. aureus</em>&nbsp;in the nares of cattle poses a threat to cattle herders, butchers, beef retailers/handlers and consumers as these cattle are frequently asymptomatic carriers hence are considered ‘healthy’. This study may evaluate the prevalence of multiple antibiotic resistant livestock associated <em>S. aureus </em>and suggest possible control to diseases caused by multiple antibiotic resistant livestock associated <em>S. aureus</em>.</p><p><strong>1.3 Objective of the Study</strong></p><p>The general objectives of the study were to evaluate the prevalence of multidrug resistant livestock associated <em>S. aureus</em>&nbsp;and suggest possible control to staphylococcal infections in humans caused by livestock associated <em>S. aureus </em>using the antibiogram of the isolates. The specific objectives are to:</p><ol><li>isolate and identify <em>S. aureus</em>&nbsp;from nasal passage of healthy cattle by Gram staining and biochemical tests (catalase test, slide coagulase test and fermentation of mannitol);</li><li>determine the antibiogram of the isolates and calculate the Multiple Antibiotic Resistance Index (M.A.R.I) using the antibiogram of the isolates;</li><li>determine the minimum inhibitory concentration (μg/disc) of the <em>S. aureus</em>&nbsp;isolates to vancomycin;</li><li>determine the minimum inhibitory concentration (μg/ml) of the isolates to flucloxacillin as a test for methicillin resistant <em>S. aureus</em>&nbsp;(MRSA) and vancomycin and</li><li>determine the synergistic, antagonistic or additive effect of two antibiotics to suggest possible control of staphylococcal infections in human caused by multidrug resistant livestock associated <em>S. aureus</em>.</li></ol><p><strong>1.4 Research Questions</strong></p><p>1. &nbsp; &nbsp; Can<em>&nbsp;S. aureus</em>&nbsp;be isolated and identified from nasal passage of healthy cattle?</p><p>2. &nbsp; &nbsp; How is the antibibiogram of <em>S. aureus</em>&nbsp;isolates determined and how are the Multiple Antibiotic Resistance Index of the isolates calculated using the antibiogram of the isolates?</p><p>3. &nbsp; &nbsp; How is the minimum inhibitory concentration (μg/disc) of <em>S. aureus</em>&nbsp;determined?</p><p>4. &nbsp; &nbsp; How is the minimum inhibitory concentration (μg/ml) of <em>S. aureus</em>&nbsp;isolated from nasal passage of healthy cattle to flucloxacillin and vancomycin determined?</p><p>5. &nbsp; &nbsp; Are the effects of the combined antibiotics synergistic, additive or antagonistic?</p><p><strong>1.5 Significance of the Study</strong></p><ol><li>This result may create more awareness on the danger of multidrug resistant <em>S. aureus</em>&nbsp;in ruminant flocks.</li><li>This result may educate the general public on the effect of negligence of multidrug resistant <em>S. aureus</em>&nbsp;in cattle and its effect in the consumption of undercooked beef.</li><li>The result may suggest possible control of staphylococcal infections in humans caused by livestock associated <em>S. aureus</em>.</li></ol><p><strong>1.6 Justification for the Study</strong></p><p>The study may provide a more recent data on multiple antibiotic resistant <em>S. aureus</em>&nbsp;and suggest possible control of livestock associated staphylococcal infections in human.</p> <br><p></p>