The sensitivity to 12 antibiotics of 125 strains of Streptococcus group B isolated in a maternity home

Sensitivity of 125 strains of group B streptococci isolated from newborns, their mothers and personnel in a maternity home was studied with respect to 12 antibiotics: benzylpenicillin, ampicillin, methicillin, cephalotin, erythromycin, lincomycin, levomycetin (chloramphenicol), oxacillin, tetracycline, streptomycin, gentamicin and ristomycin. The method of serial dilutions in a solid medium was applied. All the strains were sensitive to ristomycin and erythromycin. The predominating number of the strains were sensitive to lincomycin, levomycetin and the beta-lactam antibiotics. Strains resistant or moderately resistant to benzylpenicillin, ampicillin, oxacillin, methicillin and cephalotin were detected. The majority of the strains were resistant to streptomycin, tetracycline and gentamicin. Multiple antibiotic resistance with 2-7 determinants was revealed in 11.2 per cent of the strains. The antibiotic sensitivity of the strains isolated from the newborns, their mothers and the personnel in the maternity home was on the whole similar or insignificantly differed.     

Production of toxic shock exotoxin by Staphylococcus aureus strains resistant and sensitive to antibiotics

Three hundred and ninety two strains of S. aureus isolated from bacteria carriers and patients with staphylococcal infections in different regions of the Soviet Union were investigated. 55.9 per cent of the isolates were able to produce exotoxin of toxic shock. No regular relation between resistance to definite antibiotics (tetracycline, chloramphenicol, benzylpenicillin, streptomycin, lincomycin, erythromycin, oleandomycin, gentamicin and methicillin) and the polyresistance range on the one hand and the ability to produce toxic shock exotoxin on the other hand was revealed.     

Sensitivity of Corynebacterium diphtheriae isolated in Saint-Petersburg to antibacterial drugs]

One hundred and thirty strains of Corynebacterium diphtheriae isolated in St. Petersburg (42 toxigenic and 88 nontoxigenic) were tested with the method of serial dilutions in solid media for their susceptibility to 20 antibacterial drugs. The MICs of the drugs for the isolates ranged from < or = 0.015 to > or = 32.0 micrograms/ml. 13 per cent of the isolates was resistant at least to one antibacterial drug. The isolates resistant to erythromycin (11.5 per cent), lincomycin (11.5 per cent) and trimethoprim (8.5 per cent) were most frequent. 3 isolates (2.3 per cent) had multiple resistance to 8 drugs: benzylpenicillin, ampicillin, oxacillin, chloramphenicol, erythromycin, lincomycin, trimethoprim, and nitroxolin. No significant differences in the susceptibility of the toxigenic and nontoxigenic strains of C. diphtheriae were detected. Gentamicin, rifampicin, tetracycline, doxycycline and pefloxacin were the most active antibiotics.     

Sensitivity of Sherman's propionic acid bacilli to antibacterial preparations and vitamin B12 synthesis

Sherman propionic acid bacilli were sensitive to benzylpenicillin, ampicillin, ceporin, tetracyclines, oleandomycin, oletetrin, tetraolean, sigmamycin, levomycetin and furadonine. Methicillin, oxacillin, monomycin, kanamycin, polymyxin and furazolidone had an insignificant effect on the above organism. The subbacteriostatic concentrations of methicillin, oxacillin, streptomycin, monomycin, kanamycin, neomycin, tetraolean, sigmamycin, polymyxin M and ristomycin increased the biosynthesis of vitamin B12 by Sherman propionic acid bacilli, while benzylpenicillin, ampicillin, tetracyclines, oleandomycin, oletetrin, levomycetin and furadonine in the subbacteriostatic concentrations inhibited this process.     

Susceptibility of Coagulase-negative Staphylococci to Lysostaphin and Other Antibiotics

In general, coagulase-negative staphylococci were found to be relatively less susceptible to the lytic action of lysostaphin than coagulase-positive staphylococci. To achieve, arbitrarily, a lysis greater than 75%, it was necessary to use an increased concentration of enzyme or a longer incubation period than that usually required with coagulase-positive strains. For the most part, the cultures studied were sensitive to oxacillin, cloxacillin, dicloxacillin, nafcillin, ancillin, cephalothin, cephaloridine, fusidic acid, lincomycin, novobiocin, and neomycin [median minimal inhibitory concentrations (MIC) of 1.56 mug/ml or less]. Some degree of resistance (median MIC values of 12.5 mug/ml or greater) to benzylpenicillin, ampicillin, methicillin, tetracycline, chloretetracycline, erythromycin, ristocetin, and lysostaphin was found. Ten methicillin-resistant, coagulase-negative staphylococal strains were found to be cross-resistant to all nine of the penicillins tested, but much less resistant to the two cephalosporin analogues. In several instances, some of these strains seemed to be more sensitive to benzylpenicillin and to certain of the semisynthetic penicillins than to methicillin. Of the 18 antibiotics tested with the viable plate count method, the methicillin-resistant strains were found to be the most sensitive to lincomycin and novobiocin.     

Biological properties of sherry yeasts in the presence of antimicrobial preparations

The wine yeasts Cheres were not sensitive to high concentration (500 gamma/ml) of benzylpenicillin, streptomycin, tetracycline, oxytetracycline, chlortetracycline, morphocycline, erythromycin, oleandomycin, monomycin, neomycin, kanamycin, polymyxin, ampicillin, oxacillin, methicillin, ceporin, ristomycin, levomycetin, furadonin and furazolidone. In concentrations of 50 to 500 gamma-ml oleadomycin, chlortetracycline, oxytetracycline, kanamycin and ristomycin inhibited synthesis of the Cheres yeast biomass. Benzylpenicillin, polymyxin, neomycin and ampicillin in concentrations of 50 to 100 gamma/ml had a stimulating effect on the yeast biomass synthesis.     

Antibiotic sensitivity of staphylococci isolated from the surface of the skin of the breasts in pregnant women

Nine hundred and fourty coagulase-positive and coagulase-negative strains of staphylococci isolated from the skin surface of the mammary glands of 94 pregnant women were tested by the disc agar diffusion method for their sensitivity to five antibiotics. The highest number of the isolates were sensitive to erythromycin and lincomycin (87.7 and 89.7 per cent, respectively). The highest number of moderately resistant strains were detected with respect to methicillin. 19 out of 42 cultures of Staph. aureus were resistant to benzylpenicillin and 24 cultures were resistant to tetracycline. Among staphylococci 130 strains or 13.8 per cent were polyresistant.     

Sensitivity of Shigella to antibiotics]

Three hundred and twenty two Shigella cultures isolated from dysentery patients within 1986-1989 were tested with the use of standard paper disks for their sensitivity to levomycetin, streptomycin, tetracycline, monomycin, neomycin, kanamycin, erythromycin, gentamicin, carbenicillin, ampicillin, oxacillin, methicillin and doxycycline. The number of the cultures belonging to Shigella sonnei amounted to 85.1 per cent of the total number of the strains studied. 91.9, 89.5, 87.3, 87.3, 80.1 and 80.1 per cent of the cultures were sensitive to gentamicin, kanamycin, carbenicillin, neomycin, levomycetin and ampicillin, respectively. 99.4 per cent of the isolates were resistant to streptomycin and 97.2 per cent were resistant to tetracycline. The sensitivity to erythromycin remained rather high (70.2 per cent). The overwhelming majority of the Shigella sonnei isolates had multiple resistance.     

Antibiotic sensitivity of Staphylococci populating the breast skin of nursing women

Sensitivity to penicillins, tetracycline, erythromycin and lincomycin was tested in 1513 staphylococcal strains isolated from the skin of various anatomic areas of the breast of nursing mothers. It was shown that 82.9, 78.4 and 33.9 per cent of the isolated cultures were highly sensitive to lincomycin, erythromycin and methicillin respectively. Sensitivity to tetracycline and benzylpenicillin was detected in 33.1 and 19.8 per cent of the cultures respectively. The study of the resistance spectra of 1343 strains resistant to certain antibiotics revealed that 498 cultures (37.1 per cent) were polyresistant. None of the tested antibiotics could be used for selective decontamination of the breast skin with respect to S. aureus in prophylaxis of lactic mastitis.     

Comparative Inhibition of Methicillin-resistant Strains of Staphylococcus aureus by Lysostaphin and Otner Antibiotics

Sixteen methicillin-resistant strains of Staphylococcus aureus obtained from Europe were found to be sensitive to the lytic activity of lysotaphin. With only minor exceptions, the strains were found to be sensitive to novobiocin, erythromycin, fusidic acid, and lincomycin, and slightly less sensitive to vancomycin and chloramphenicol. All strains were resistant to tetracycline, penicillinase-sensitive penicillins (benzylpenicillin, ampicillin, and propicillin), penicillinase-resistant penicillins (methicillin, nafcillin, ancillin, oxacillin, cloxacillin, and dicloxacillin), and two cephalosporin antibiotics (cephalothin and cephaloridine).     

114株肺炎链球菌的临床分布及药敏分析

目的波市妇女儿童医院肺炎链球菌的临床分布和耐药情况,为临床合理用药提供依据。方法对该院2009年6月1日至2011年3月31日期间分离的114株肺炎链球菌进行分析,菌株鉴定采用法国生物梅里埃公司的VITEK60分析仪,药敏试验采用K-B法,用参考菌株做质量控制。结果该院分离的肺炎链球菌主要来自儿童（84.21%）,标本来源主要是痰液（61.4%）,其次是血液（9.65%）,其他（28.95%）。肺炎链球菌的耐药率：林可霉素92.19%,红霉素90.12%,青霉素G85.53%,左旋氧氟沙星20.24%,氨苄西林16.67%,头孢唑啉8.7%,头孢曲松5.8%,头孢噻肟4.11%,万古霉素0%,氨苄西林/舒巴坦0%,哌拉西林/他唑巴坦0%。结论宁波市妇女儿童医院肺炎链球菌对某些药物的耐药率很高,有必要对其进行耐药率监测,指导临床合理选择抗菌药物。     

Method of oblique illumination in studying the morphology of Staphylococcus aureus colonies sensitive and resistant to antibiotics]

The morphology of the colonies of Staph. aureus sensitive and resistant to antibiotics and the colonies with artificial resistance to benzylpenicillin, ampicillin, oxacillin, methicillin, cephaloridin and lincomycin was studied with the method of slanting light. Changes in the morphology of the colonies were most pronounced at the beginning of the microbial resistance development first of all in the cultures of Staph. aureus resistant to cephaloridin and lincomycin.     

Sensitivity to antibiotics of pneumococci isolated from patients with chronic nonspecific pneumonia and bronchitis

Four hundred and twenty two pneumococcal strains isolated from 300 patients with chronic nonspecific pneumonia and bronchitis were studied with respect to their sensitivity to 18 antibiotics within a period from 1982 to 1985. It was shown with the method of serial dilutions on solid media that 91.7, 87.8, 85 and 81 per cent of the isolates were sensitive to benzylpenicillin, ampicillin, lincomycin and cefuroxime, respectively. A significant percentage of the pneumococcal strains had decreased sensitivity to benzylpenicillin (MIC close to the therapeutic concentration). On this basis it was recommended to use lower concentrations of benzylpenicillin (less than 0.25 units/ml) in assay of sensitivity in clinical strains of Pneumococcus.     

Antibiotic sensitivity of the causative agents of suppurative surgical infection]

Sensitivity of 1492 strains of the causative agents of the surgical purulent infections, i. e. pathogenic Staphylococcus, Proteus, Ps. aeruginosa and E. coli to benzylpenicillin, streptomycin, levomycetin, tetracycline, erythromycin, oleandomycin, monomycin, kanamycin, novobiocin, ampicillin, oxacillin, ceporin, gentamicin and rifampicin was studied. Gentamicin was most active against all the bacterial species tested. The staphylococci were in addition sensitive in a high percentage of the cases to rifampicin, novobiocin, ceporin, monomycin and kanamycin. The isolates of E. coli were in addition sensitive to ceporin, monomycin and kanamycin. Sensitivity of the strains of Ps. aeruginosa and Proteus was low to all of the antibiotics except gentamycin. Most of the strains of the causative agents of the surgical purulent infections were multiresistant to 4 antibiotics. The number of the staphylococcal strains sensitive to benzylpenicillin, streptomycin and levomycetin increased in 1976 as compared to 1975 on the background of a limited use of these antibiotics in clinics.     

Resistance of some strains ofBacteroides to ampicillin,methicillin and cloxacillin

Twenty-three strains of thefragilis-convexus group ofBacteroides and two strains of thethetaiotaomicron group have been tested for sensitivity to ampicillin, methicillin and benzylpenicillin. Thirteen of these strains (twelve of thefragilis-convexus group and one of thethetaiotaomicron group) have been tested to cloxacillin, tetracycline, chloramphenicol and erythromycin.The strains proved to be resistant to benzylpenicillin, ampicillin, methicillin and cloxacillin.     

Moraxella catarrhalis in chronic and relapsing respiratory tract infections in children]

Examination of 700 children with chronic and relapsing respiratory tract infections showed that during the period from 1996 to 2003 Moraxella catarrhalis strains were isolated from the sputum of 5.5-9.7% of the patients. The frequency of the emergence was the third after Haemophilus influenzae and Streptococcus pneumoniae. In healthy children M. catarrhalis was isolated in 2.7% of the cases. The most frequent detection of M. catarrhalis was stated in children under 1 year (4.5%). The antibiotic susceptibility tests revealed that the majority of the M. catarrhalis isolates had beta-lactamase activity, were resistant to benzylpenicillin, ampicillin and lincomycin and highly susceptible to amoxycillin/clavulanate, macrolides, certain cephalosporins and levofloxacin. The isolates were most frequent in the patients of the rather severe contingent (congenital lung disease, alveolitis, chronic pneumonia, bronchial asthma). In such patients the bronchoobstructive syndrome was more frequent (46.6%). High frequency of the affection of the upper respiratory tracts in the examined children was stated (62.1%).     

Sensitivity of the causative agent of tularemia to antibiotics

Sensitivity of the tularemia causative agent of different geographical races to antibiotics such as streptomycin, tetracycline, gentamicin, rifampicin (20 strains), ampicillin, polymyxin M, erythromycin, oleandomycin (361 strains) and lincomycin (294 strains) was studied. High sensitivity of the tularemi a microbe to streptomycin, tetracycline, rifampicin (MIC of 10 gamma/ml), gentamicin (MIC of 1 gamma/ml) and resistance to 50 gamma of ampicillin and 1000 gamma/ml of polymyxin M were found. Combined use of 50 gamma of ampicillin and 100 gamma/ml of polymyxin M added to the nutrient medium for growth inhibition of the foreign flora on isolation of the tularemia causative agent from the infected material including stable laboratory animal carcases was recommended. Marked differences in sensitivity of the strains of different geographical races to the macrolides and lincomycin were observed. The strains of the non-Arctic and Central Asiatic races were of low resistance to the above drugs (the MIC of erythromycin, oleandomycin and lincomycin were 10--50, 50--400 and 25--100 gamma/ml respectively. Within the holarctic race 40 per cent were low resistant and 60 per cent were highly resistant to these drugs. The above drugs should not be used for treatment of tularemia cases.     

Distribution and characteristics of <Emphasis Type="Italic">Bacillus</Emphasis> bacteria associated with hydrobionts and the waters of the Peter the Great Bay,Sea of Japan

Bacilli of the species Bacillus subtilis, B. pumilus, B. mycoides, B. marinus and B. licheniformis (a total of 53 strains) were isolated from 15 invertebrate species and the water of the Vostok Bay, Peter the Great Bay, Sea of Japan. Bacilli were most often isolated from bivalves (22.7%) and sea cucumbers (18.9%); they occurred less frequently in sea urchins and starfish (13.2 and 7.5%, respectively). Most of bacilli strains were isolated from invertebrates inhabiting silted sediments. No Bacillus spp. strains were isolated from invertebrates inhabiting stony and sandy environments. The species diversity of bacilli isolated from marine objects under study was low. Almost all bacterial isolates were resistant to lincomycin. Unlike B. pumilus, B. subtilis isolates were mostly resistant to benzylpenicillin and ampicillin. Antibiotic sensitivity of B. licheniformis strains was variable (two strains were resistant to benzylpenicillin and oxacillin, while one was sensitive). A significant fraction of isolated bacilli contained pigments. Pigmented strains were more often isolated from seawater samples, while colorless ones predominated within hydrobionts. B. subtilis colonies had the broadest range of colors. In the Bacillus strains obtained, DNase, RNase, phosphatase, elastolytic, chitinase, and agarolytic activity was detected. Bacilli strains with hydrolytic activity occurred in invertebrates more often than in seawater.     

Antimicrobial susceptibility of some streptococci strains of anginosus group isolated from oral and maxillofacial infections

Streptococci strains of the anginosus group isolated from various oral and maxillofacial infections (OMF) were screened for their susceptibility to the following antimicrobial agents: benzylpenicillin, ampicillin, oxacillin, cephalothin, ceftazidime, cefotaxime, cefuroxime, erythromycin, clindamycin, tetracycline, chloramphenicol, vancomycin and trimethoprime-sulphamethoxazole. The isolates were susceptable to: clindamycin, chloramphenicol, vancomycin and all beta-lactam antibiotics, except ceftazidime to which 54.5% of the strains showed intermediate susceptibility. Intermediate susceptibility to tetracycline was found in 11.3% of the strains, whereas resistance to the same antibiotic was demonstrated in 61.4%. Resistance to erythromycin and trimethoprime-sulphamethoxazole was of 2.3% for both. In conclusion, penicillin is the drug of choice in infections caused by streptococci of the anginosus group.     

Distribution and characteristics of Bacillus bacteria associated with hydrobionts and the waters of the Peter the Great Bay, Sea of Japan

Bacilli of the species Bacillus subtilis, B. pumilus, B. mycoides, B. marinus and B. licheniformis (a total of 53 strains) were isolated from 15 invertebrate species and the water of the Vostok Bay, Peter the Great Bay, Sea of Japan. Bacilli were most often isolated from bivalves (22.7%) and sea cucumbers (18.9%); they occurred less frequently in sea urchins and starfish (13.2 and 7.5%, respectively). Most of bacilli strains were isolated from invertebrates inhabiting silted sediments. No Bacillus spp. strains were isolated from invertebrates inhabiting stony and sandy environments. The species diversity of bacilli isolated from marine objects under study was low. Almost all bacterial isolates were resistant to lincomycin. Unlike B. pumilus, B. subtilis isolates were mostly resistant to benzylpenicillin and ampicillin. Antibiotic sensitivity of B. licheniformis strains was variable (two strains were resistant to benzylpenicillin and oxacillin, while one was sensitive). A significant fraction of isolated bacilli contained pigments. Pigmented strains were more often isolated from seawater samples, while colorless ones predominated within hydrobionts. B. subtilis colonies had the broadest range of colors. In the Bacillus strains obtained, DNase, RNase, phosphatase, elastolytic, chitinase, and agarolytic activity was detected. Bacilli strains with hydrolytic activity occurred in invertebrates more often than in seawater.