Schaefler S, Francois W, Ruby C L
Antimicrob Agents Chemother. 1976 Apr;9(4):600-13. doi: 10.1128/AAC.9.4.600.
Tetracycline-resistant strains of Staphylococcus aureus are minocycline sensitive, with the exception of strains susceptible to phages of the 83A/84/85 complex and some methicillin-resistant strains of other phage types. Strains of the 83A/84/85 complex yield mutants with increased minocycline resistance. Transduction of minocycline resistance into the susceptible strain RN 450 was obtained with donor strains possessing either markers for both extrachromosomal tetracycline resistance (tet) and chromosomal tetracycline + minocycline resistance (tmn R), or only for chromosomal tmn R resistance. The chromosomal marker was differentiated from the extrachromosomal marker by the lack of detectable extrachromosomal deoxyribonucleic acid after transfer into strain RN 450, transfer into a rec(+) strain, lack of transfer into rec(-) acceptor strain, and cotransduction with chromosomal determinants for guanine biosynthesis. Both chromosomal and extrachromosomal tetracycline resistance can be induced by tetracycline. Induction by tetracycline of chromosomal tetracycline resistance resulted in simultaneous induction of minocycline resistance. The mutation toward increased minocycline resistance (tmn --> tmn R) is a regulatory mutation toward constitutivity or semiconstitutivity. Constitutive resistance is dominant in tmn R/tet diploids. Transfer of the tet marker does not affect the phage susceptibility of the acceptor strain. The tmn R marker, originating from donor strains of the 83A/84/85 complex, renders strain RN 450 resistant to several typing phages, with the exception of phages of the 83A/84/85 complex. This could possibly account for the phage typing patterns of minocycline-resistant staphylococci.
金黄色葡萄球菌的四环素耐药菌株对米诺环素敏感，但对83A/84/85复合体噬菌体敏感的菌株以及其他噬菌体类型的一些耐甲氧西林菌株除外。83A/84/85复合体的菌株产生对米诺环素耐药性增加的突变体。用具有染色体外四环素耐药性（tet）和染色体四环素 + 米诺环素耐药性（tmn R）标记的供体菌株，或仅具有染色体tmn R耐药性标记的供体菌株，可将米诺环素耐药性转导至敏感菌株RN 450中。通过以下方法可将染色体标记与染色体外标记区分开来：转入菌株RN 450后检测不到染色体外脱氧核糖核酸、转入rec(+)菌株、无法转入rec(-)受体菌株以及与鸟嘌呤生物合成的染色体决定簇共转导。染色体和染色体外的四环素耐药性均可由四环素诱导产生。四环素诱导染色体四环素耐药性会同时诱导米诺环素耐药性。向米诺环素耐药性增加方向的突变（tmn --> tmn R）是向组成型或半组成型的调节突变。在tmn R/tet二倍体中，组成型耐药是显性的。tet标记的转移不影响受体菌株的噬菌体敏感性。源自83A/84/85复合体供体菌株的tmn R标记使菌株RN 450对几种分型噬菌体耐药，但83A/84/85复合体的噬菌体除外。这可能解释了耐米诺环素葡萄球菌的噬菌体分型模式。
