Threlfall E J, Chart H, Ward L R, de Sa J D, Rowe B
Laboratory of Enteric Pathogens, Central Public Health Laboratory, Colindale, London, UK.
J Appl Bacteriol. 1993 Jul;75(1):43-8. doi: 10.1111/j.1365-2672.1993.tb03405.x.
Salmonella enteritidis strain P278849 expressed long-chain lipopolysaccharide (LPS, termed 'smooth'), carried plasmids of 38, 34 (pDEP 44, incompatibility group N, R-type AS), 2.0 and 1 MDa, and belonged to phage type (PT) 23. Introduction of pDEP 44 into a smooth strain of Salm. enteritidis PT 4 produced a smooth strain of Salm. enteritidis of PT 24. Transfer of this plasmid into a strain of PT 8 also resulted in formation of a smooth strain of Salm. enteritidis of PT 24. Moving pDEP 44 into strains of Salm. enteritidis of PTs 7 or 7a which did not express LPS (termed 'rough') resulted in rough strains of PT 23. In contrast, transfer of this plasmid into a smooth strain of Salm. enteritidis PT 7a resulted in a smooth strain of PT 23. Introduction of pDEP 44 into strains of Salm. enteritidis of PT 13 or PT 13a did not change the phage type, whereas transferring the plasmid into strains of PT 30 caused strains to become resistant to lysis by the typing phages and therefore untypable. The possibility of strains of Salm. enteritidis of PT 8 being the progenitors of strains of Salm. enteritidis of PT 24 must now be considered when investigating the epidemiology of Salm. enteritidis of PT 24 infections in areas where Salm. enteritidis PT 8 is common.
肠炎沙门氏菌菌株P278849表达长链脂多糖（LPS，称为“光滑型”），携带38、34（pDEP 44，不相容群N，R型AS）、2.0和1兆达尔的质粒，属于噬菌体分型（PT）23型。将pDEP 44导入肠炎沙门氏菌PT 4的光滑型菌株中产生了PT 24型的肠炎沙门氏菌光滑型菌株。将该质粒转移到PT 8菌株中也导致形成了PT 24型的肠炎沙门氏菌光滑型菌株。将pDEP 44转移到不表达LPS（称为“粗糙型”）的肠炎沙门氏菌PT 7或7a菌株中导致了PT 23型的粗糙型菌株。相反，将该质粒转移到肠炎沙门氏菌PT 7a的光滑型菌株中导致了PT 23型的光滑型菌株。将pDEP 44导入肠炎沙门氏菌PT 13或PT 13a菌株中不会改变噬菌体分型，而将该质粒转移到PT 30菌株中会导致菌株对分型噬菌体的裂解产生抗性，因此无法分型。在调查PT 8型肠炎沙门氏菌常见地区PT 24型肠炎沙门氏菌感染的流行病学情况时，现在必须考虑PT 8型肠炎沙门氏菌菌株可能是PT 24型肠炎沙门氏菌菌株的祖先这一可能性。
