Bacterial Interference by Streptococcus salivarius

Transcription

1 Bacterial Interference by Streptococcus salivarius NANCY J. BILL, B.S.M.T. (ASCP), AND JOHN A. WASHINGTON II, M.D. Mayo Clinic and Mayo Foundation, Rochester, Minnesota ABSTRACT Bill, Nancy J. and Washington, John A., II: Bacterial interference by Streptococcus salivarius. Am J Clin Pathol 64: , A strain of Streptococcus salivarius, recognized in a throat culture because of its inhibition of the growth of a species of Corynebacterium, was studied in vitro to determine its antagonistic effects against various other bacteria. It was found to be inhibitory to anaerobic Gram-positive cocci, streptococci belonging to Lancefield's groups A, C, F, and G, and Corynebacterium diphtherial, C. hofmanii, and C. xerosis. (Key words: Bacterial interference; Bacterial antagonism.) VmiDANS STREPTOCOCCI have been shown to be inhibitory to Neisseria meningitidis, 2,18 N. elongata, 9 Moraxella, 9 /3-hemolytic streptococci, 1 ' 3,4,18 Corynebacterium diphtheriae, 23 pneumococci, 13 Staphylococcus aureus, 17 ' 18 Escherichia coli, 8 and group III mycobacteria. 7 Inhibition by Streptococcus faecalis var. zymogenes of the growth of Clostridium perfringens has also been described. 12 Although Johanson and associates 13 found Streptococcus salivarius to be the major species of the viridans group to inhibit pneumococci, there are no reports of this particular species' antagonism to a variety of other bacteria. This study was prompted by the isolation, from a throat culture, of a strain of 5. salivarius that was inhibitory to a Corynebacterium species, as shown in Figure 1. Materials and Methods The ability of the strain of S. salivarius to inhibit the growth of other bacteria was Received November 25, 1975; accepted for publication December 23, Address reprint requests to Dr. Washington. 116 tested by a method described by Henriksen and Fuglesang. 9 The other species to be studied were inoculated in closely spaced, parallel streaks on blood agar or other suitable agar media, and the S. salivarius, grown in a broth culture to a turbidity matching that of a McFarland no. 1 standard, was inoculated in one streak at a right angle to these streaks. The media were then incubated under capneic or anaerobic conditions for 24 to 48 hours at 35 C. Bacterial interference was considered to have occurred when there was inhibition of the experimental strain in the vicinity of the area inoculated with the 5. salivarius. Results Bacterial interference was found with Peptococcus, Peptostreptococcus, Aerococcus viridans, Staphylococcus salivarius, Corynebacterium diphtheriae, C. hofmanii, C. xerosis, and /3-hemolytic streptococci belonging to Lancefield's groups A, C, F, and G (Table 1). An illustration of the inhibitory activity is shown in Figure 2. The inhibitory activity was destroyed by boiling a 24-hour broth culture of the organism for 30 minutes and was absent

2 July 1975 BACTERIAL INTERFERENCE BV S. SAUVARIUS 117 w y :! K V i ^W^w*^ I fe> B ft FIG. 1. Throat culture on a blood agar plate, showing large numbers of colonies of a Corynebacterium species and inhibitory zones around colonies of Streptococcus salivarius. in a cell-free filtrate of a 24-hour broth culture. Discussion Bacterial interference has been recognized for many years, and was reviewed by Florey 5 in The potential protective role played by the commensal microflora in man has been suggested by a number of reports. Sprunt and coworkers 21,22 reported studies suggesting that viridans streptococci prevent the overgrowth of gram-negative bacilli in the oropharynx. Studies by Crowe and associates 3 and Johanson and co-workers 13 suggest a similar role for viridans streptococci in protecting against oropharyngeal colonization by group A streptococci and pneumococci. There have been several reports of the antagonistic effects of the short-chain fatty acids produced by intestinal anaerobic bacteria against Pseudomonas aeruginosa and some members of the family Enterobacteriaceae, including shigellae. 6,1015 Inhibition of gonococci by Staphylococcus

3 118 BILL AND WASHINGTON A.J.C.P. Vol.64 FIG. 2. Inhibition of growth of a group A /3-hemolytic streptococcus produced by a cross-streak from a broth culture of Streptococcus salivarius. epidermidis 14 and by meningococci 25 has been reported. Shinefield and associates 20 utilized bacterial interference to curtail epidemics of staphylococcal infections in newborns in the nursery. The precise mechanism of bacterial interference is unknown. Hamon and Klebanoff 8 described a peroxidasemediated system of bacterial interference by S. mitis dependent on microbial metabolism of H Antagonistic activity by group A streptococci and by S. sanguis attributable to the action of peroxide has been described by Malke and colleagues 16 and by Holmberg and Hallander, 11 respectively. Johanson and associates 13 hypothesized that the inhibitor is a bacteriophage or bacteriocin, but in the opinion of Trust 24 and Wolff and Duncan 26 it is an antibiotic rather than a bacteriocin because of its antagonism against many bacteria unrelated to the producer strain, its low molecular weight, and its autoinhibitory properties. Shedlofsky and Freter 19 presented data demonstrating a definite synergism between the effects of local immunity and bacterial interference, particularly in the mouth, throat, or large bowel. Additional considerations in explaining the antagonism are the possible

4 July 1975 BACTERIAL INTERFERENCE BY S. SAUVARIUS 119 depletion of an essential substrate from the growth medium and the creation of an unphysiologic environment by the inhibitor strain. 18 Of interest in our study was the antagonism against the anaerobic Grampositive cocci exhibited by our isolate of 5. salivarius. It is apparent, from comparing our results with those in other reports, however, that there are intrageneric, if not intraspecies, differences in the inhibitory properties manifested by viridans streptococci. Therefore, in oropharyngeal and intestinal commensals, there is likely to be a spectrum of inhibitory activity whose mechanism is as yet poorly understood, but whose clinical importance appears to be well established. References 1. Bartels HA, Blechman H, Lorieo D: The in vitro inhibition of beta streptococci by an oral streptococcus (abstr). J Dent Res 39:687, Colebrook L: Bacterial antagonism, with particular reference to meningococcus. Lancet 2: , Crowe CC, Sanders WE Jr, Longley S: Bacterial interference. II. Role of the normal throat flora in prevention of colonization by group A Streptococcus. J Infect Dis 128: , Deepika P, Slade HD: A bacteriocidal factor synthesized by Streptococcus mutans (abstr). Abstr Annu Mtg Am Soc Microbiol, 1974, p Florey WH: The use of micro-organisms for therapeutic purposes. Yale J Biol Med 19: , Freter R, Abrams GD: Function of various intestinal bacteria in converting germfree mice to the normal state. Infect Immun 6: , Gelbart SM, Tonaki H, Adams R: An a-hemolytic Streptococcus with lytic activity specific for group III mycobacteria. Am Rev Resp Dis 109: , Hamon CB, Klebanoff SJ: A peroxidasemediated, Streptococcus mitis-dependent antimicrobial system (abstr). Clin Res 20:529, Henriksen SD, Fuglesang JE: Antagonistic action of alpha haemolytic streptococci on Neisseria elongata. Acta Pathol Microbiol Scand [B] 81: , Hentges DJ, Maier BR: Inhibition of Shigella flexneri by the normal intestinal flora. III. Interactions with Bacteroides fragilis strains in vitro. Infect Immun 2: , Holmberg K, Hallander HO: Production of bactericidal concentrations of hydrogen Table 1. Effects of Streptococcus salivarius on Growth of Other Bacteria Peptococcus Peptostreptococcus Aerococcus viridans Streptococcus, group A Streptococcus, group C Mycobacterium tuberculosis Inhibited Streptococcus, group F Streptococcus, group G Corynebacterium diphtheriae C. xerosis Not Inhibited C. hofmanii Staphylococcus salivarius Streptococcus, group B M. kansasii Streptococcus, group D M. avium (intracellular) Streptococcus mutans M. scrofulaceum S. pneumoniae M.fortuitum Listeria monocytogenes Haemophilus influenzae, type B Bacteroides fragilis Escherichia coli Proteus mirabilis H. parainfluenzae P. stutzeri Acinetobacter catcoaceticus Pseudomonas aeruginosa Alcaligenes spp. P. maltophilia Eikenella corrodens P. cepacia Moraxella spp. P. fluorescens M. osloensis peroxide by Streptococcus sanguis. Arch Oral Biol 18: , Jayne-Williams DJ: A medium for overcoming the in vitro inhibition of Clostridium perfringens by Streptococcus faecalis var. zymogenes, and a note on the in vivo interaction of the two organisms. J Appl Bacteriol 36: , Johanson WG Jr, Blackstock R, Pierce AK, et al: The role of bacterial antagonism in pneumococcal colonization of the human pharynx. J Lab Clin Med 75: , Kraus SJ, Ellison N: Resistance to gonorrhea possibly mediated by bacterial interference. Appl Microbiol 27: , Levison M: Effect of colon flora and short-chain fatty acids on growth in vitro of Pseudomonas aeruginosa and Enterobacteriaceae. Infect Immun 8:30-35, Malke H, Starke R, Jacob HE, et al: Bacteriocine-like activity of group-a streptococci due to the production of peroxide. J Med Microbiol 7: , 1974

5 120 BILL AND WASHINGTON A.J.C.P. Vol Myers DM: An antibiotic effect of viridans bacterial overgrowth. J Infect Dis 123:1-10, streptococci from the nose, throat, and sputum, 1971 and its inhibitory effect on Staphylococcus 22. Sprunt K, Redman W: Evidence suggesting aureus. Am J Clin Pathol 31: , 1959 importance of role of interbacterial inhibition 18. Sanders E: Bacterial interference. I. Its occurrence among the respiratory tract flora and Intern Med 68: , 1968 in maintaining balance of normal flora. Ann characterization of inhibition of group A 23. Thompson R, Shibuya M: The inhibitory action streptococci by viridans streptococci. J Infect of saliva on the diphtheria bacillus: The Dis 120: , 1969 antibiotic effect of salivary streptococci. J 19. Shedlofsky S, Freter R: Synergism between Bacteriol 51: , 1946 ecologic and immunologic control mechanisms of intestinal flora. J Infect Dis 129: Can J Microbiol 16: , Trust TJ: Antagonism by a gram-positive coccus , Volk J, Kraus SJ: Asymptomatic meningococcal urethritis: possible protective value against 20. Shinefield HR, Ribble JC, Boris M: Bacterial gonococcal infection by bacteriocin production. Br J Vener Dis 49: , 1973 interference between strains of Staphylococcus aureus, 1960 to Am J Dis Child 26. Wolff LF, Duncan JL: Studies on a bactericidal 121: , 1971 substance produced by group A streptococci. 21. Sprunt K, Leidy GA, Redman W: Prevention of J Gen Microbiol 81: , 1974 News and Notices Breast Cancer Demonstration Projects Please be advised that all Pathologists in the United States and Canada are being asked to cooperate with the American Cancer Society/ National Cancer Institute Breast Cancer Demonstration Projects in the following way. There are 27 Centers functioning across the country. Recommendations regarding surgical investigation are being made to the physicians of record of the 270,000 patients being examined by x-ray and physical examinations. These patients are being treated in any hospital in the United States and Canada. Each of the Centers has a Pathologist of Record, and one of his responsibilities will be to request slides, blocks and a copy of your findings to complete his recordkeeping and professional responsibilities to his Center. Please cooperate with him in every way that you can. He has been asked to relate his findings to you as soon as possible. It is the intent of these Projects to follow these patients for ten years. Our role as Pathologists is vital to the success of this Project, and I hope you will cooperate as fully as possible. I will be happy to answer or amplify any and all questions directed to me or will obtain an answer if I do not have the information. William H. Hartmann, M.D. Department of Pathology Vanderbilt University School of Medicine Nashville, Tennessee, Phone: