Campylobacter outsmarts Antibiotics
SCIENTISTS from UKZN’s Antimicrobial Research Unit recently conducted a study, the results of which produced what has been labelled as the “most read paper” on Researchgate.net.
The paper was the first published by Nigerian-born PhD student Ms Christiana Shobo, who is the first author. It was featured in the peer-reviewed: Journal of Infection in Developing Countries.
Shobo’s study, supervised by Dr Linda Bester and the Director of UKZN’s Antimicrobial Research Unit – who is also the SARChI Chair in Antibiotic Resistance and One Health – Professor Sabiha Essack, investigated the antibiotic resistance profiles of Campylobacter species in the South African private health care sector. Campylobacteriosis is the most common bacterial cause of human gastroenteritis in the world causing 400 to 500 million cases of diarrhoea each year.
Campylobacter infection is primarily a zoonotic disease as it is found in food animals, particularly poultry, which serve as the main reservoir for human infection. Other sources of transmission include water, milk, and animal meat products. Gastroenteritis may be characterised by watery, non-bloody, non-inflammatory diarrhoea progressing to severe inflammatory diarrhoea followed by abdominal pain and fever.
In South Africa, there is insufficient data on clinical Campylobacter, particularly in the private healthcare environment, which prompted the study. Seventy two clinical isolates from patients with diarrhoea or dysentery were collected from a private laboratory in Durban and analysed between October 2013 and September 2014.
Infection was seen to be higher among male patients (63.9%) compared to females. The most affected group were infants and toddlers under two years old. This is in line with international studies which indicate that infants with developing immune systems are more prone to infection than adults. Older patients who were also immune-compromised had increased infection rates. The majority of the samples were also collected during spring.
Of the total patients, 47.2% had severe infections that warranted hospitalisation. Increasing antibiotic resistance to Campylobacter has become a substantial and significant public health concern in both developing and developed countries. First-line antibiotics are usually prescribed and those with macrolides (erythromycin), fluoroquinolones (ciprofloxacin) and tetracycline are recommended.
In South Africa, other studies have observed a steady increase in macrolide, fluoroquinolone and tetracycline resistance in Campylobacter. In this study, authors found a 23.6% resistance to ciprofloxacin and 8.3% to gatifloxacin. A further 33% resistance was recorded to erythromycin. Multi-resistance presents a risk to humans by limiting the therapeutic choice of antibiotics.
The Campylobacter bacteria is usually found in the intestinal tract of warm-blooded animals such as poultry and pigs, and frequently detected in foods derived from these animals. According to the World Health Organisation, the burden of food-borne diseases, including Campylobacteriosis, is substantial: every year almost one in 10 people fall ill and 33 million healthy life years are lost.
Food-borne diseases can be severe, especially for young children. Diarrhoeal diseases are the most common illnesses resulting from unsafe food, with 550 million people falling ill annually. The species can be killed by heat and thoroughly cooking food. To prevent Campylobacter infections, basic food hygiene practices need to be followed when preparing food.
First author Shobo completed her Higher National Diploma (Microbiology) at Moshood Abiola Polytechnic (MAPOLY) in Nigeria before joining UKZN’s College of Health Sciences where she obtained a scholarship for her Masters degree in Medical Sciences and for her PhD.
Shobo and her team, led by Dr Linda Bester, are recipients of the College of Health Sciences Young Researchers Competitive grant of R250 000 awarded to young researchers with novel studies.