Phage Typing Patterns Research Articles

High-frequency transfer of neomycin resistance between naturally occurring strains of Staphylococcus aureus.

SUMMARY A naturally occurring neomycin-resistant strain of Staphylococcus aureus was found to donate its resistance, together with cross-resistance to kanamycin and paromomycin, to a variety of sensitive staphylococci. The transfer occurred spontaneously and at relatively high frequency both in broth cultures and experimentally on the skin surface of volunteers. The mechanism of the transfer was transduction, which is believed to be mediated by an element composed of a defective prophage of serological group B and a determinant for neomycin resistance. The latter is probably located on a plasmid in the resistant cell, since strains harbouring the element tended to lose their resistance spontaneously, particularly at high temperatures. The effect of UV light on the transduction of the element was also characteristic of known plasmids. The phage-typing patterns of staphylococci able to acquire the neomycin-resistance marker in vitro were limited but similar to those of naturally occurring resistant strains. Since neomycin resistance of the type found naturally could not be established in the laboratory, it is probable that the acquisition of neomycin resistance may have occurred in vivo by high-frequency transduction.

Phage Types of multidrug resistant Salmonella species in a rural area of Maharashtra, India

Objective: The aim of the present study is to know Phage typing and antimicrobial susceptibility pattern of Salmonella species. Methods: A total of 32 Salmonella species isolated from stool and blood specimen were included in the study. They were sent for phage typing to Lady Hardinge Medical College, New Delhi. Antimicrobial susceptibility was done by using Kirby Bauer disc diffusion method. Results: Majority of Salmonella typhi belongs to phage type E1 and biotype I. Decreased susceptibility of the isolate was observed to Ampicillin, Cotrimoxazole, Cephalexin and Gentamicin. Majority of the isolates were sensitive to Ciprofloxacin. Conclusion: Predominant phage type was E1. The antibiotic sensitivity pattern is changing and resistant cases are emerging due to inappropriate use of antibiotics. DOI: http://dx.doi.org/10.3329/bjms.v11i1.9821 BJMS 2012; 11(1): 37-39

TETRACYCLINE-RESISTANCE TRANSDUCTION AND TYPING PATTERN 29 IN STAPHYLOCOOCUS AUREUS

Transduction experiments of tetracycline resistance were carried out on staphylococcus aureus of typing pattern 29/52/80/81, tetracycline (TC)-streptomycin (SM) -sensistive, penicillin (PC) -resistant, and phage type 29/52/52A/80/81 (TC-, SM-, PC-, sensistive) strains with the prophages obtained from strains of phage type 80/81 and phage type 52/80/81, which are TC-, SM-, PC-reristant.It was observed that recipient strains aquired the TC resistance and also changed the typing pattern into that of the donors, losing the sensitivity to the typing phages 29, 29/52 and 29/ 52/52A. However, the transduction of SM-resistance did not accompanied a chnge of typing pattern.These results suggest that the genetic factor governing the TC-resistance is closely linked to that of phage typing pattern 29.

The Characteristics of Staphylococcus aureus Isolated from Cases of Staphylococcosis in Poultry

SUMMARY The results of this investigation indicate that strains of Staphylococcus aureus possessing alpha haemolysin are now associated more frequently with staphylococcosis in poultry than formerly. These strains were found to be resistant to penicillin and tetracycline more frequently than the other strains examined and to resemble human strains in possessing delta-lysin also, but not beta-lysin. The possible influence of the feeding of antibiotics to poultry on the emergence of strains of this type is discussed. The distribution of phage typing patterns among the strains of Staph. aureus associated with staphylococcosis in poultry was found to be quite unlike that found in a random collection of human strains, although similarities occurred with some of them. Strains of Staph. aureus present on the skin and in the upper respiratory tract of infected fowls were found to have characteristics similar to those of strains isolated from internal lesions.

Changes in the Phage-Typing Patterns of Staphylococci Following Lysogenization

The phage typing patterns of phage type 52/52A/80/81 staphylococcal strains were changed to type 80/81 and the non-typable group by lysogenization with phages 27 and 146. When a particular strain of Staphylococcus aureus, MS1590 phage type 52/52A/80/81, was lysogenized with phage 146, type 80/81 and the non-typable group strains were produced. According to the comparison of host range of the prophages, it has been concluded that the two strains with different phage typing patterns have different kinds of prophages.

Loss of antibiotic resistance in Staphylococcus aureus resulting from growth at high temperature.

SUMMARY: Fifty strains of Staphylococcus aureus resistant to penicillin or tetracycline or both were examined for loss of these two resistances as the result of growth at 43-44°. Twelve strains showed a loss of penicillin resistance under the experimental conditions, and of these twelve, three showed a loss of tetracycline resistance. The two resistances were lost independently; in strains in which both resistances were lost most of the sensitive variants had lost one or other resistance but not both. However, penicillin resistance was lost only in strains that were also tetracycline-resistant and vice versa. All strains in which a loss of resistance occurred had similar phage-typing patterns and all belonged to the ‘52, 52A, 80, 81 complex’ of strains. Not all strains in the complex, however, showed a loss of resistance. Both penicillin and tetracycline resistance were transduced into suitable sensitive recipients. The results showed that the heat-sensitivity of the transduced resistance was the same as in the donor in which the transducing phage was propagated. The results are consistent with the hypothesis that these two resistances are carried by two separate plasmids, at least in certain strains of S. aureus. Nine multiply-resistant strains of Staphylococcus aureus were examined for loss of resistance to antibiotics other than penicillin and tetracycline as the result of growth at elevated temperatures. These other antibiotics included streptomycin, erythromycin, novobiocin, oleandomycin, neomycin and bacitracin. In no case was any loss of resistance observed.

Staphylococcus aureus strains in the "52, 52A, 80, 81 complex".

THE phage-typing pattern of a strain of Staphylococcus aureus is believed to be determined by two factors: the ‘basic’ sensitivity of the strain to lysis by the typing phages, modified by interference exerted by the prophage or prophages it carries. The specificity of this interference may be narrow, and prevent lysis only by the phage carried by the strain and by closely related phages, or it may be very broad. Sometimes a single prophage will block the sensitivity to a number of apparently unrelated phages and have a profound effect on the phage-typing pattern1,2.

Lysogenic Conversion of Staphylococci to Loss of -Toxin

SUMMARY Staphylococci may produce β-toxin and staphylokinase (fibrinolysin). In clinical material there is a preponderance of strains which are β-toxin negative and kinase positive (β –K+), but β +K–, β –K– and β +K+ strains also occur. Strains which are β +K– can be converted by lysogenization with certain phages to loss of β-toxin and gain of kinase (β –K+). This is true conversion, since every lysogenized coccus carries the new characters. All the phages which produced this double conversion (β –K+ phages) belong to the serological group F. The conversion is due to two separate loci on the phage which are active in the prophage state. These loci have not been found in phages of other serological groups (β 0K0 phages). The β-toxic and fibrinolytic properties of staphylococci are not always phage-dependent; strains which do not carry detectable phages or carry only β 0K0 phages can be either β +K–, β –K+, β +K+ or β –K–, implying the occurrence of structural loci on the bacterial genome. Several strains with the phage-typing pattern 80/81 or a related pattern, which are β –K+, were found to carry converting phages. On loss of these phages the strains became β +K–. and showed a change of typing-pattern, gaining sensitivity for phages of group III.

DRUG RESISTANCE OF STAPHYLOCOCCI. I. TRANSDUCTION OF TETRACYCLINE RESISTANCE WITH PHAGE LYSATES OBTAINED FROM MULTIPLY RESISTANT STAPHYLOCOCCI.

Mitsuhashi, Susumu (Gunma University, Maebashi, Japan), Hiroshi Oshima, Umeko Kawaharada, and Hajime Hashimoto. Drug resistance of staphylococci. I. Transduction of tetracycline resistance with phage lysates obtained from multiply resistant staphylococci. J. Bacteriol. 89:967-976. 1965.-Tetracycline resistance was found to be transduced with phage lysates obtained from multiply resistant strains of Staphylococcus aureus of human origin. With various combinations of multiply resistant donors and tetracycline (TC)-sensitive recipients, almost all of the strains were found to be competent donors. A greater percentage of group 1 staphylococci were competent recipients. Most of the TC(+) transductants were not lysogenic for the transducing phage and were unable to transduce TC resistance with their own phage lysates obtained by ultraviolet irradiation. However, the TC(+) transductants, lysogenized with transducing phage, were capable of transducing TC resistance, and some of the lysogenizations were accompanied by changes in phage type. These results suggest that the emergence of the multiply resistant staphylococci (consistently resistant to TC) can be accounted for by transduction among various strains accompanied sometimes by changes in phage typing pattern after lysogenization, and by selection through extensive use of antibiotics and chemotherapeutic agents.

Lysogeny in staphylococci.

Blair, John E. (Hospital for Joint Diseases, New York, N. Y.) and Miriam Carr. Lysogeny in staphylococci. J. Bacteriol. 82:984-993. 1961.-Changes in the phage typing patterns of strains of staphylococci of the 80/81-52/52A/80/81 complex and of phage group III were produced by lysogenization with temperate phages derived from selected strains of Staphylococcus aureus. The phages used were of the serological groups A, B, and F. Certain changes of phage pattern were related to serologically specific prophage immunity; others were nonspecific, or resulted from the conversion of a strain from partial resistance to full sensitivity to certain typing phages. In addition to an alteration of their phage typing pattern, the lysogenization of certain strains by appropriate phages effected a reversal of their susceptibility to penicillin. The capacity to produce toxin was conferred upon certain nontoxigenic strains by lysogenization with a phage derived from a toxigenic strain.

The lysogenicity of Staphylococci isolated in Poland.

SUMMARY: Strains of staphylococci were tested for lysogenicity and different ‘lysogenicity patterns’ were defined on the basis of the phage lytic spectra. The test of lysogenicity was used to indicate the pathogenicity, and to complement the phagetyping pattern. None of the coagulase-negative strains (65) carried a phage. The lysogenicity patterns of 76% of the coagulase-positive strains (122 tested) were determined. With the method of phage typing 80 % of the coagulase-positive strains of staphylococci were classified. By using both methods (phage-typing and the test of lysogenicity) the classification of 92 % of coagulase-positive strains was possible. Differentiation of identical phage-typing patterns was obtained by using lysogenicity patterns.

Distribution of Phage Groups of Staphylococcus aureus in the Years 1927 through 1947

The phage typing patterns of 194 typable strains of Staphylococcus aureus isolated in the years 1927 through 1947 and preserved as stock cultures revealed that 43 strains were of phage type 80/81. The occurrence of other typable strains in the broad phage groups I, II, and III corresponded closely to the frequency distribution of staphylococci reported in 1945 by Wilson and Atkinson.

Changes in the Phage-Typing Patterns of Staphylococci Following Lysogenization

SUMMARY: Staphylococcal strains which showed a range of reactions with the phages 47 C, 52, 52 A, 80 and 81 were examined for changes in phage sensitivity following artificial lysogenization. The lysogenic phages used were isolated from strains of three different phage-typing patterns and differed in serology. The changes in phage reactions thus produced included: (1) immunity to the B phages, 52, 52 A and 80 produced by a B phage; (2) immunity to the A phage 81 produced by a serologically unrelated F phage; (3) immunity to phage 47 C and sensitivity to phages 52 and 52 A produced by a number of A phages. The mechanisms whereby a variety of typing patterns may be obtained within a related group of staphylococci are discussed.