Lab Matters Summer 2019 - Page 8

FEATURE course. And nearly all US dairy cows are given prophylactic, intramammary drug infusions—typically penicillins or other beta-lactam drugs—to prevent mastitis. Antibiotics are also used as pesticides. The US Environmental Protection Agency, for example, is in the process of re-approving the use of streptomycin for wholesale spraying on apple, pear and nectarine trees to control citrus canker and citrus greening disease. Tennessee microbiologists Michelle Therrien and Justin Simpson process carbapenem-resistant Enterobacteriaceae specimens. Photo: TDH DLS Even if we have perfect antibiotic prescribing and use, AR would still be a problem, largely because of the transmission of [existing] resistant pathogens.” Michael Craig, MPP “Whenever and wherever you use antibiotics, resistance is going to follow” The problem of antibiotic resistance (AR) has been decades in the making. James “Albert” Burks, IV, MLS(ASCP), RN, who oversees carbapenem-resistance testing at the TDH Division of Laboratory Services explained that antibiotic research and development “slacked off” beginning in the mid-1980s, when an array of potent antibacterial agents was readily available. At the same time, he said, physicians began prescribing antibiotics for conditions like sinus infections, now known to be mostly viral and unresponsive to antibacterial drugs. “Patients were taking [antibiotics] until they felt better when the lifecycle of the virus was complete; they weren’t taking the full regimen,” said Burks. Consequently, mildly drug-resistant pathogens were able to survive and evolve. Outside the healthcare arena, antibiotics have also been overused in veterinary and agricultural settings. In fact, agricultural usage of antibiotics far exceeds their healthcare usage. Farmers administer the drugs not only to treat acute animal illness, but also to prevent illness and to enhance animal growth. According to one estimate, about 90% of pigs raised for food in the US get tetracyclines or similar drugs in their feed as a matter of 6 LAB MATTERS Summer 2019 Global developments have exacerbated the problem. In 2010, India was the world’s largest consumer of antibiotics for human health, followed by China. According to researchers Ramanan Laxminarayan and Ranjit Roy Chaudhury, a perfect storm of poor public health systems, high rates of infectious disease, inexpensive antibiotics and rising incomes has led to the proliferation of resistant pathogens in many parts of the world and especially the BRICS countries—Brazil, Russia, India, China and South Africa. Increased demand for meat and poultry in places like India has fueled even greater agricultural antibiotic use. Michael Craig, MPP, CDC’s senior advisor for AR, said, “Whenever and wherever you use antibiotics, resistance is going to follow.” He said, “We take for granted sometimes that antibiotics are really the scaffolding that makes surgical procedures possible, organ transplants possible, invasive disease treatments possible. All of those are risky, and people susceptible to infections are vulnerable. When antibiotics start to be ineffective, the risk-benefit profiles of those treatments change; doctors might not Tennessee’s GC AR Lab Network Team (from l to r): Robin Rasnic, Arianna Allgood, Erica Terrell, Brielle Davis and Henrietta Hardin. Photo: TDH DLS PublicHealthLabs @APHL