Test accurately and swiftly detects most leading causes of bacterial blood stream infection

A new automated diagnostic test can quickly and accurately identify most leading causes of Gram-positive bacterial blood stream infections and the presence of three antibiotic resistance genes, according to a new study published this week in PLOS Medicine. The findings from the study, conducted by a team of researchers led by Nathan Ledeboer from the Medical College of Wisconsin (MCW), USA, suggest that the new technology could lead to faster diagnosis and treatment of patients suffering from sepsis.

Severe sepsis is a life-threatening condition that is usually triggered by a of the bloodstream. In the most severe cases of sepsis multiple organs can fail and in the US alone sepsis causes up to 250,000 deaths a year. The outcome of sepsis is affected by many factors, but fast, accurate identification of the bacterial infection and determination of its antibiotic susceptibility is essential to ensure that patients receive appropriate antibiotics. In the study published this week the researchers evaluated a new test, called Verigene BC-GP, that has been designed to simultaneously detect the DNA of 12 species of Gram-positive bacteria, which are the most common cause of bacterial , and three in cultures grown from patient blood samples.

The researchers evaluated the Verigene BC-GP test using 1252 blood cultures from five US clinical centers and 397 contrived cultures (that contained rarer found in infections) compared to standard culture techniques. They found that the test was able to correctly identify patients who were positive for a specific infection in 92.6% to 100% of samples and to correctly determine patients that did not have a specific infection in 94.5-100% of samples. However, about 7.5% of cultures contained Gram-positive bacteria that the test was not designed to detect. The researchers also found that the test was able accurately identifying three genes (the mecA, vanA, and vanB genes), which confer resistance to the antibiotics vancomycin and methicillin. The test takes about 2 hours to run and in an analysis of 107 blood culture broths the researchers found the test was able to return a result about 42 hours faster than the conventional culture methods.

The researchers say, "[t]he high sensitivity and specificity characteristics of this test, coupled with on-demand testing capability and a [2 hour turnaround time] enable reporting of both the identification and antimicrobial resistance genes of bacteria obtained from blood culture significantly faster than using routine culture methods."

The faster diagnosis should improve the care of patients with by allowing physicians to prescribe appropriate antibiotics much earlier than is currently possible.

More information: Buchan BW, Ginocchio CC, Manii R, Cavagnolo R, Pancholi P, et al. (2013) Multiplex Identification of Gram-Positive Bacteria and Resistance Determinants Directly from Positive Blood Culture Broths: Evaluation of an Automated Microarray-Based Nucleic Acid Test. PLoS Med 10(7): e1001478. doi:10.1371/ journal.pmed.1001478

add to favorites email to friend print save as pdf

Related Stories

Less commonly prescribed antibiotic may be better

Aug 16, 2012

The antibiotic most commonly prescribed to treat bloodstream infections in dialysis patients may not always be the best choice, according to a study appearing in an upcoming issue of the Journal of the American Society of ...

Antibiotics: Change route of delivery to mitigate resistance

Jun 26, 2013

New research suggests that the rapid rise of antibiotic resistance correlates with oral ingestion of antibiotics, raising the possibility that other routes of administration could reduce the spread of resistance. The manuscript ...

Recommended for you

A new way to diagnose malaria, using magnetic fields

15 hours ago

Over the past several decades, malaria diagnosis has changed very little. After taking a blood sample from a patient, a technician smears the blood across a glass slide, stains it with a special dye, and ...

How Alzheimer's peptides shut down cellular powerhouses

Aug 29, 2014

The failing in the work of nerve cells: An international team of researchers led by Prof. Dr. Chris Meisinger from the Institute of Biochemistry and Molecular Biology of the University of Freiburg has discovered ...

User comments