The in vitro effect of antimicrobial agents on guinea pig polymorphonuclear leukocyte (PMN) chemotaxis was studied. Antimicrobial agents investigated in this study are penicillin-G (PC G). ampicillin (ABPC), cloxacillin (MCI PC), cephalothin (CET), erythromycin (EM), gentamicin (GM), colistin (CL), chloramphenicol (CP), tetracycline (TC), sulfoisoxazole (SI) and amphotericin-B (AMPH-B) at the concentration between 0.005μg/ml and 1000μg/ml.
PAN chemotzxis was strongly suppressed by almost all drugs at a very high concentration. CET, CL, SI or AMPH-B acts PMN directly and inhibits leukocyte chemotaxis without suppression of chemokinesis. Both chemokinesis and chemotaxis are suppressed by CP or TC. MCI PC or EM acts PMN as if it is one of the chemoattractants, so that each drug inhibits leukocyte chemotaxis by the mechanism of deactivation.
The results are discussed with paticular emphasis on the implications to host defence mechanism.

View full abstract

Two series of clinical isolates of Streptococcusp yogenes subcultured from the throat swabs of the patients with acute infectious diseases at the pediatric outpatient clinic, Sendai National Hospital, Sendai City, were subjected to this study.
The first series of the study was performed with the antibiotic susceptibility of 52 strains isolated from February to August, 1976, to ABPC, AMPC, ACPC, SBPC, Piperacillin (T-1220), CER, CEZ, CET, CEX, CLDM, JM, JM-P, EM, CP, TC, and MNC, determined as the minimal inhibitory concentration (MIC) by an agar dilution method. All the strains were found sensitive to both penicillins and cephalosporins, the antibacterial activity being in this order ABPC=AMPC> T-1220> ACPC> SBPC, CER>CEZ> CET> CEX, respectively. ighly cross resistant strains (MIC≥100μg/ml) to macrolides including CLDM were demonstrated.
Measurements of antibiotic susceptibility to PC G, ABPC, CER, EM, CP, and TC as well as serotyping were made on 110 strains of Streptococcus pyogenes, as the second series of the study, isolated from April 1976 to March 1977. The distribution frequency of each serotype by utilizing T-typing revealed: T-12, 45 strains (40.9%); T-1, 30 strains (27.3%); T-4, 10 strains (9.1%); T-28, 9 strains (8.2%); T-22, 6 strains (5.5%); B 3264, 3 strains (2.7%); Imp. 19, l strin (0.9%); T-25, l strain (0.9%); nontypable, 5 strains (4.5%). The characterisitics of the distribution of resistant patterns in relation to serotypes were:(a) that all of the EM·ECP·ETC resistant strains were T-12, (b) that TC-single resistance distributed in T-1, T-4, T-12, T-28, and T-22, and (c) that all the strains of B 3264, Imp. 19, and T-25 were sensitive to all the antibiotics examined.
The relationship of serotype and resistant pattern, the difference in the distribution of serotype and resistant pattern between isolates from Sendai area and those from other parts of Japan, and a possibility in the future of penicillin-resistant Streptococcus pyogenes comparing to Streptococcus pneumoniae have been briefly discussed.

View full abstract

For many years Serratia was considered incapable of causing human infections, but more recently this organism has been recognized as a cause of infections in chronic deblitating deseases. The respiratory tract has been more common site of such infections.
This study was done to assess the incidence and significance of Serratia in respiratory tract infections and to investigate the clinical picture of the patients infected.
There was a striking increase in the incidence of S. marcescens isolated from the sputum of hospitalized patients in the passed 7 year period, 1971 to 1977.
Thirty five patients, from whom this organism was isolated in a large number with other organisms in 7 years, were retrospectively investigated their clinical situation. Most of the patients suffered from diseases of the central nervous system associated with respiratory distress, chronic respiratory diseases and/or malignancy. Large numbers of the patients were postoperative and/or had antibiotics for a long time. From these facts, the opportunistic or nosocomial nature of S. marcescens was demonstrated by the high percentage of patients with facters lowering host resistance.
This study showed that Serratia infections are an important component of hospital infection and no longer possible to consider this organism as nonpathogen.

View full abstract