Viral respiratory tract infections can often be complicated by bacterial co-infections and this can be the case in particular with COVID-19 infection. Note that secondary infections are not diagnosed before hospitalisation, and are observed in intensive care (15% of cases), also that misdiagnosis is a factor.

CHROMagar™ MH Orientation, a chromogenic Mueller Hinton agar was developed with the aim of speeding up the time to result by combining the chromogenic differentiation of species and an antibiotic susceptibility test, therefore allowing same-day results for both, unlike the traditional protocol which takes 48 hours.

One potential application, in parallel to standard routine procedures, is in the processing of samples from ICU patients with Ventilated Associated Pneumonia (VAP), which is one of the most frequent ICU nosocomial infections with high morbidity and mortality. Shortening the time period, to deliver empirical therapy, results in better outcomes.

As stated by a Spanish team leader in this protocol, plating respiratory samples directly onto CHROMagar™ MH Orientation is "a rapid procedure for antimicrobial susceptibility testing (...) crucial for modifying therapeutic regimens".¹

Several studies have underlined that direct specimen antibiotic-susceptibility testing on a CHROMagar™ MH Orientation plate is a simple technique providing an early determination of the microorganism and antimicrobial susceptibility data which is key to supplying the appropriate therapy with the final aim to save lives and reduce healthcare costs.

Key Features and Benefits:

• 2 in 1: Chromogenic differentiation and antibiotic susceptibility in the same plate.
• Fast results: Can be read just after overnight incubation.
• Easy plate reading: Diameters and/or inhibitions zones are clearly defined.

1. Evaluation of direct E-test on lower respiratory tract samples using a chromogenic agar medium: a rapid procedure for antimicrobial susceptibility testing” E. Cercenado and al, ECCMID 2009