Friday, May 20, 2016

EID Journal: Multidrug-Resistant Staphylococcus aureus, India, 2013–2015

Credit CDC


In 2013 the CDC published a report listing the top 18 drug-resistant threats to the United States.   While CDIFF, CRE, and Neisseria gonorrhea were listed as the most urgent concerns, not far behind they listed a dozen 2nd tier threats, including multi-drug and Methicillin-Resistant Staphylococcus Aureus (MRSA).

Despite its significant morbidity and mortality, MRSA was relegated to a second tier threat primarily because there remain a few `last ditch' drugs (vancomycin, daptomycin, and linezolid) available to treat it, and because invasive MRSA infections in healthcare settings was seen as being as being on the decline in the U.S. in recent years.

The concern with MRSA, as with all drug resistant bacterial infections, is that it could eventually develop pan-resistance -  where no effective treatment option remains.

This week the EID Journal carries a letter describing MRSA surveillance and testing at a single hospital in Odisha, eastern India. Although the number of samples tested was small (n=47), they detected several samples displaying disturbing co-resistance to methicillin, vancomycin, linezolid, and tigecycline.

First some excerpts from the letter, then I'll return with a bit more.

Volume 22, Number 9—September 2016


Multidrug-Resistant Staphylococcus aureus, India, 2013–2015
To the Editor: Methicillin-resistant Staphylococcus aureus (MRSA) is a versatile pathogen capable of causing a wide variety of human diseases. Increased frequency of S. aureus infections imposes a high and increasing burden on healthcare resources. In many countries, MRSA infections in hospitals are common. Data from the National Nosocomial Infections Surveillance system suggest that, in the United States, incidence of nosocomial MRSA infections is steadily increasing and that these infections account for >60% of intensive care unit admissions (1,2). 

S. aureus has developed resistance to several antimicrobial drugs, including second- and third-line drugs. Only a few drugs, such as vancomycin (a glycopeptide), daptomycin (a lipopeptide), and linezolid (an oxazolidinone), have been approved for the treatment of serious infections caused by MRSA. Another drug, tigecycline (a glycylcycline), has shown good activity against MRSA strains in vitro (3). 

 The epidemiology of MRSA is constantly changing, which results in variation in its drug-resistance patterns throughout regions and countries (4). Therefore, to support clinicians in preventing and treating infection, epidemiologic surveillance is essential. We report resistance patterns of S. aureus collected over 2 years (December 2013–November 2015) from blood samples of patients admitted to 1 hospital in Odisha, eastern India.


This study indicates the emergence of multidrug-resistant S. aureus with co-resistance to methicillin, vancomycin, linezolid, and tigecycline. Although the clinical significance of these findings is unknown, the decline in drug effectiveness against S. aureus infections represents a looming threat to patient health and highlights the possibility of a return to illness and death rates similar to those before antimicrobial drugs were available.

While the media loves to bombard us with apocalyptic warnings of global warming, asteroid strikes, and super volcanoes erupting, the slow motion disaster of growing antibiotic resistance is the one that is most likely to reach criticality my lifetime (and I'm a relatively old man).
Although certainly not alone in this regard, India has played a huge role in the emergence and spread of antibiotic resistant organisms, a topic we've explored numerous times, but most recently in Three Reports On India's Growing Antibiotic Crisis.
For some more recent blogs on the antibiotic resistance crisis, you may wish to revisit:

ECDC EFSA Report: Antimicrobial Resistance On The Rise In The EU

Gonorrhea: The Path Of Increased Resistance

The Lancet: Dissemination Of The MCR-1 Colistin Resistance Gene 

MCR-1: The Return Of The Plasmids


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