Plain language summary

What is this summary about?Pseudomonas aeruginosa (P. aeruginosa) is a type of bacteria that can make people ill. There are only a few medicines or drugs that can be used to treat illness caused by P. aeruginosa that is resistant to multiple drugs (such as multidrug resistant (MDR) and extensively drug-resistant (XDR) P. aeruginosa). This summary is about a study that collected P. aeruginosa samples (isolates) from patients across the world and tested medicines, including ceftazidime avibactam (CAZ-AVI), for their ability to stop the growth of P. aeruginosa samples in the laboratory (meaning, in a test tube).What are the key takeaways?29,746 P. aeruginosa samples were collected globally from various regions (Latin America, Europe, Middle East, Africa, Asia Pacific, and North America). Of these: About 21% were multidrug resistantAbout 21% were extensively drug resistantAbout 8% were CAZ-AVI resistant, meaning CAZ-AVI could not stop the growth of these isolates.The highest proportion of resistant isolates was found in Latin America.CAZ-AVI was able to stop the growth of most P. aeruginosa (susceptibility 91%, meaning 9 in 10 bacteria could not grow in the presence of the drug). For multidrug resistant and extensively drug-resistant P. aeruginosa isolates, CAZ-AVI showed lower activity against resistant isolates (susceptibility 61% or less) compared to P. aeruginosa isolates overall.The only other medicines that could stop the growth of most P. aeruginosa were colistin (susceptibility 99%) and amikacin (susceptibility 91%). However, colistin was the only other drug capable of stopping the growth of most multidrug resistant and extensively drug-resistant P. aeruginosa isolates (susceptibility 98% or more). Amikacin had lower activity (susceptibility 61% or less) against resistant P. aeruginosa isolates compared to P. aeruginosa isolates overall.What were the main conclusions reported by the researchers?CAZ-AVI stopped the growth of most P. aeruginosa. CAZ-AVI can be used to treat illness caused by P. aeruginosa. It is important to monitor the spread of P. aeruginosa, including resistant isolates, and to keep checking whether medicines such as CZ-AVI can stop the growth of these isolates so that infections caused by these isolates can be treated effectively[Box: see text].