Pyocin Typing of Pseudomonas aeruginosa : a Simplified Method

Abstract

A simplified method has been devised for typing Pseudomonas aeruginosa by pyocin production. Pyocins are produced as strains grow overnight in Trypticase soy broth (without glucose) plus 1% potassium nitrate. Because P. aeruginosa can use nitrate instead of oxygen as a terminal electron acceptor, mechanical shaking is not necessary, nor is induction by mitomycin C. Pyocins can now be produced in screw-cap tubes in a water bath or incubator. A total of 250 strains were tested as possible pyocin indicators, which included 60 strains already used in pyocin-typing systems. The final set contained 18 indicators which were chosen because (i) they had clear positive or clear negative reactions, thus eliminating reactions difficult to read, (ii) they had few zones due to bacteriophage lysis, and (iii) they were most sensitive in differentiating clinical isolates of P. aeruginosa . The final typing method was tested in several studies and the results were clear; thus definitive epidemiological conclusions could be made. Because it is simple to perform and easily automated, the new method should have application in many hospitals; however, it should be used only in carefully planned epidemiological studies. The method and its application are described in detail, and some pitfalls are discussed.

Evolutionary and ecological role of extracellular contractile injection systems: from threat to weapon

“…Importantly, during this period, it was found that R-type pyocins have a more efficient killing activity than headless mutants of a related phage, supporting the hypothesis that these particles are not simply defective prophages but evolved weapons ( Shinomiya and Shiga, 1979 ). Additionally, their advantage for medical use was explored, employing pyocins for P. aeruginosa typing ( Farmer and Herman, 1969 ; Rose et al, 1971 ; Edmonds et al, 1972 ; Lovrekovich et al, 1972 ; Jones et al, 1974 ; Duncan and Booth, 1975 ; Bruun et al, 1976 ; Fyfe et al, 1984 ; Schable et al, 1986 ) as well as a potential treatment against P. aeruginosa infections ( Merrikin and Terry, 1972 ; Haas et al, 1974 ). In addition to all these findings, a new type of phage tail-like pyocin, the F-type, was discovered ( Takeya et al, 1969 ; Govan, 1974b ; Kuroda et al, 1979 ; Kuroda and Kageyama, 1979 , 1981 ; Michel-Briand and Baysse, 2002 ; Saha et al, 2023 ).…”

“…The usage of eCISs for potential biotechnological applications is not a recent concept. These particles were already used in the 1970s as a tool for P. aeruginosa typing or “fingerprinting” to better identify, investigate and control outbreaks ( Farmer and Herman, 1969 ; Rose et al, 1971 ; Edmonds et al, 1972 ; Lovrekovich et al, 1972 ; Jones et al, 1974 ; Duncan and Booth, 1975 ; Bruun et al, 1976 ; Fyfe et al, 1984 ; Schable et al, 1986 ). Furthermore, as multi-drug resistant bacterial infections are becoming more frequent and more difficult to treat, the high specificity of eCISs, specifically R-tailocins, has interesting potential for medical applications in the treatment of nosocomial P. aeruginosa infections.…”