The recent increase in antibiotic-resistant organisms is a challenge to physicians and pharmaceutical companies. Newer, rapid molecular-diagnostic tests and novel antibiotics may equip healthcare providers with the necessary tools to successfully combat these life-threatening infections. Dr Stefan Riedel, associate professor of pathology and infectious diseases at Johns Hopkins University, provides some insight.
Methicillin-resistant Staphylococcus aureus (MRSA) has long been feared as a cause of severe infections. Dr Stefan Riedel, associate professor of pathology and infectious diseases at John Hopkins University, explains that this organism commonly colonises the nares, however, systemic MRSA infections may be difficult to treat, particularly when resistance to other antibiotics has been acquired.
Moreover, MRSA infections can be extremely difficult to control in environments such as hospitals, prisons and nursing homes, where the organism can easily spread. Riedel says: "While MRSA is a healthcare burden in many countries, the Netherlands was able to maintain fairly low rates due to its national search and destroy strategy, designed to identify patients at risk for MRSA. Isolation of patients at risk, rapid organism identification and eradication of MRSA carriage are the core elements to keep MRSA rates among the lowest, worldwide."
Riedel, a clinical pathologist and microbiologist, established his research laboratory as a centre for surveillance of antimicrobial resistance. He says: "Multidrug-resistant organisms (MDROs), like MRSA, are often transmitted from community settings back into various healthcare settings." Physicians should consider this when attempting to decrease the burden of MDROs.
Recently, antimicrobial resistance in Gram-negative organisms such as extended-spectrum beta-lactamase (ESBL) and carbapenemase (KPC) producers have added to global resistance. Riedel explains: "Rapid diagnostic methods to identify key organisms and resistance genes, and surveillance studies to detect emerging antibiotic resistances are essential to curb antibiotic resistance."
Advancing molecular testing
Much of Riedel's work involves testing bacteria from clinical patient specimens such as blood, sputum and wounds, against a broad range of current antibiotics. Using collections of bacterial organisms, Riedel's team performs antimicrobial susceptibility testing for immediate clinical use, and for regional and national surveillance studies. Riedel says: "This work helps us to see trends of resistance. The goal is to monitor changes in resistance patterns, and to enhance our understanding of how antibiotic resistance emerges and changes over time."
Molecular-diagnostic test methods are increasingly used by clinicians, providing them with faster turnaround time for results in order to implement appropriate treatment interventions, even for more complex infections due to Gram-negative (MDRO) organisms.
"Molecular methods are providing those faster results, including some of the key resistance genes," argues Riedel. "At the moment, the organism still needs to be grown in culture first, but that's certainly a step ahead, a few hours compared with days using traditional laboratory methods."
As these technologies improve further - particularly in conjunction with innovations in next-generation sequencing (NGS) technologies - this looks to become even faster with a better understanding of the genetic markers of resistance. "What I see is a rapidly evolving field of molecular-diagnostic tests, and ultimately the use of NGS technology for diagnosis, surveillance and epidemiologic studies," Riedel says.
Before long, physicians should have the methods available to rapidly identify organisms from primary patient specimens, using the genome data to identify or predict antibiotic susceptibility and resistance. However, it may require many more years before such technology can be implemented for routine patient care.
One company leading the development in the ongoing battle against antibiotic resistance is OpGen, a provider of tools to eradicate life-threatening, drug-resistant infections. In a CLIA-certified diagnostic laboratory, OpGen technology allows clinicians to accurately screen for, diagnose, prevent and manage MDRO threats and infections.