Effect of antibiotic therapy and vaccine therapy on the phagocytic reaction in mice infected with Staphylococcus

The time course of changes in the activity, intensity and completeness of phagocytosis with leukocytes of the peritoneal exudate was studied on mice with experimental staphylococcal infection treated with rifampicin, lincomycin and inactivated staphylococcal vaccine used alone or in combination. It was shown that immunization of the animals with inactivated staphylococcal vaccine promoted stimulation of the phagocytic defense. Rifampicin and lincomycin applied therapeutically induced a decrease in the activity, intensity and completeness of phagocytosis. It should be noted that rifampicin had a less pronounced inhibitory effect than lincomycin. The combined use of vaccine and antibiotics with therapeutic purposes promoted an increase in phagocytosis as compared to the use of the antibiotics alone. The combined therapy sometimes resulted in completeness of phagocytosis making it reach the control values (the 10th and 15th days, rifampicin and vaccine). It should be noted that a more pronounced stimulation of the activity, intensity and completeness of the phagocytosis was observed with the use of the combination of rifampicin and the vaccine.     

The influence of antibiotics on phagocytic and bacteriocidal activity of rabbit peritoneal macrophages stimulated by filtrates of cultured t-lymphocytes

The aim of the study was to determine the influence of twelve antibacterial antibiotics (various concentrations) on the activation of rabbit peritoneal macrophages. Macrophages were stimulated by filtrates of culture of lymphocytes T obtained from OVA immunized rabbits. Phagocytic activity and intracellular killing against Listeria monocytogenes were tested by fluorescence method. Penicillin G (0.4-50 mg/l), erythromycin and lincomycin (2.5-40 mg/l) used at all concentrations, were not exerting significant effects on activation of peritoneal macrophages. Cephalosporins, aminoglycosides, and rifampicin at low concentrations (0.4-5.0 mg/l) had no influence on phagocytosis and intracellular killing, also. Cephalosporins at concentration 10 mg/l (cephradine and cefamandole) and 50 mg/l (cefotaxime) inhibited intracellular killing and phagocytic activity. The same results were observed with ampicillin and ticarcillin (50 mg/l). The highest suppression effect was demonstrated using rifampicin at concentration 10 mg/l or more. Gentamicin, streptomycin and amicacin at concentrations 40 mg/l or more significantly inhibited macrophage activation in response to filtrates lymphocytes of culture. These inhibitions were more marked with gentamicin (10 mg/l) than amicacin (20 mg/l) or streptomycin (40 mg/l). All antibiotics did not stimulated the activity of peritoneal macrophages. The suppression activity of peritoneal macrophages by some antibiotics probably acts at the level of specific immune system by interfering with cytokine production.     

Effect of antibiotic and vaccine therapies on the succinate dehydrogenase and phosphatase activity of liver cells of mice infected with Staphylococcus

Changes in the activity of succinate dehydrogenase (SDH), total and acid phosphatase (TP and AP) were studied in treatment of laboratory animals with rifampicin, lincomycin and with inactivated staphylococcal vaccine used alone or in combinations. It was shown that immunization of the animals with inactivated staphylococcal vaccine under conditions of experimental staphylococcal infection promoted stimulation of the enzyme activity. Rifampicin and lincomycin used for the treatment of such animals lowered the activity of the enzymes. The suppressing effect of the antibiotics increased with an increase in the period of their use. It should be noted that the inhibitory effect of rifampicin on the activity of SDH, TP and AP was less pronounced than that of lincomycin. The combined use of the vaccine and antibiotics for the treatment of the animals promoted an increase in the enzyme activity as compared to the use of the antibiotics alone. Sometimes the activity of SDH, TP and AP reached the control levels in such animals or the levels observed in the animals treated with the vaccine alone. Stimulation of the enzyme activity was more pronounced when the vaccine was used in combination with rifampicin.     

阿魏酸钠对肺结核模型小鼠免疫功能及肺泡巨噬细胞吞噬功能的调控作用研究

摘要 目的：探讨与分析阿魏酸钠对肺结核模型小鼠免疫功能及肺泡巨噬细胞吞噬功能的调控作用。方法：肺结核模型小鼠(n=36)随机分为模型组、利福平组、阿魏酸钠组,每组各12只。利福平组、阿魏酸钠组分别给予100 mg/kg剂量的利福平与阿魏酸钠,模型组小鼠灌胃等量生理盐水,1次/d,给药6周,观察与记录所有小鼠的一般特征;分别于给药第2周、第4周、第6周,HE染色观察小鼠的病理特征;MDA检测试剂盒和总SOD活性检测试剂盒测定肺组织MDA水平与SOD活性;流式细胞仪检测小鼠T淋巴细胞亚群-CD3⁺T淋巴细胞、CD4⁺T淋巴细胞水平;酶联免疫法检测血清IL-6、IL-8含量;AnnexinV-FITC检测肺泡巨噬细胞凋亡率。结果：利福平组、阿魏酸钠组给药第2周、第4周、第6周的肺组织丙二醛（Malondialdehyde,MDA）水平低于模型组（P<0.05）,超氧化物岐化酶（superoxide dismutase,SOD）活性高于模型组（P<0.05）,利福平组与阿魏酸钠组对比也有明显差异（P<0.05）。利福平组、阿魏酸钠组给药第2周、第4周、第6周的血液CD3⁺T淋巴细胞、CD4⁺T淋巴细胞比例明显高于模型组（P<0.05）,阿魏酸钠组也高于利福平组（P<0.05）。利福平组、阿魏酸钠组给药第2周、第4周、第6周的血清IL-6、IL-8含量明显低于模型组（P<0.05）,阿魏酸钠组也低于利福平组（P<0.05）。利福平组、阿魏酸钠组给药第2周、第4周、第6周的肺泡灌洗液（broncho alveolar lavage fluid,BALF）巨噬细胞凋亡率明显低于模型组（P<0.05）,阿魏酸钠组也明显低于利福平组（P<0.05）。结论：阿魏酸钠在肺结核模型小鼠的应用可抑制炎症因子的表达,并改善氧化状况,还能增强小鼠的免疫功能,降低肺泡灌洗液巨噬细胞凋亡率。     

Effect of lytic enzymes on Staphylococcus and the possibilities of their combined use with antibiotics

Dependence of lytic enzyme preparation activity on temperature and time of Staphylococcus incubation with the preparation was shown. A decrease in the activity with an increase in the ionic strength of the incubation solutions and protective effect of salts on the staphylococcal cells were observed. Possible combined use of the preparation with antibiotics was studied. The enzymatic preparation inactivated penicillins and cephalosporins at the account of the ability of lytic endopeptidases to hydrolyze the peptide bond of the beta-lactam ring. However, its combined use with many other antibiotics such as novobiocin, lincomycin, rifampicin, gramicidin, polymyxin, oleandomycin, streptomycin, kanamycin, tetracycline and levomycetin is quite possible.     

Effect of Inoculum Size on In Vitro Susceptibility Testing with Lincomycin

There is disagreement in the literature as to whether lincomycin is primarily a bacteriostatic or a bactericidal agent against gram-positive cocci and also regarding the levels of activity of this agent against susceptible microorganisms. These questions were examined in a study of the effect of inoculum size on the results of tube dilution susceptibility determinations with lincomycin against 49 clinical isolates of Staphylococcus aureus and 25 strains of streptococci and pneumococci. Lincomycin was both highly active and bactericidal when tested against 40 strains of S. aureus with inocula containing a maximum of 10(4) cells per ml [median minimal inhibitory concentration (MIC), 0.78 mug/ml; median minimal bactericidal concentration (MBC), 1.56 mug/ml]. With inocula of 10(5) cells per ml, lincomycin was primarily bacteriostatic (median MIC, 1.56 mug/ml; median MBC, 12.5 mug/ml). There were further decreases in inhibitory levels and significant losses of bactericidal activity when inocula containing more than 10(7) cells were tested (median MIC, 3.13 mug/ml; median MBC > 100 mug/ml). Similar measurements with streptococci and pneumococci revealed a lesser effect of inoculum size. The mean MBC value for alpha-hemolytic streptococci increased from 0.40 to 1.05 mug/ml with an increase in inocula from 10(4) to 10(6) cells per ml, but without a marked increase in MIC values. Similar results were obtained for beta-hemolytic streptococci and pneumococci.     

Bacteriostatic and bactericidal activity of antituberculosis drugs against Mycobacterium tuberculosis, Mycobacterium avium-Mycobacterium intracellulare complex and Mycobacterium kansasii in different growth phases.

Bacteriostatic and bactericidal activities of rifampicin, isoniazid, streptomycin, enviomycin and ethambutol against Mycobacterium tuberculosis, Mycobacterium avium--M. intracellulare complex and Mycobacterium kansasii were studied in different growth phases. Bacteriostatic activities of the drugs were similar in different growth phases, except isoniazid. M. tuberculosis was much less susceptible to isoniazid in the lag phase than in the log and the stationary phases. In contrast, bactericidal activity was influenced by the growth phase. M. tuberculosis was killed by isoniazid, streptomycin and rifampicin. The bactericidal activity of isoniazid was strongest. The bactericidal activity of isoniazid and streptomycin was most marked in the log phase. M. avium complex and M. kansasii resisted the bactericidal activity, but some strains of M. avium complex were killed by streptomycin and enviomycin, and the activities of these two drugs were most marked in the lag phase.     

Enhancement of bactericidal activity of mouse peritoneal macrophages against Staphylococcus aureus by mouse interferon preparations

The effect of mouse interferon on the bactericidal activity of macrophages against pyogenic cocci was examined. Mouse peritoneal macrophages were cultivated with Staphylococcus aureus in vitro and viable Staphylococcus was recovered by treatment of the mixed macrophage-bacteria culture with sodium dodecyl sulphate (SDS) solution. Results showed that S. aureus was phagocytized and killed by the macrophages. Mouse L cell interferon enhanced the bactericidal activity of macrophages. A mouse brain interferon preparation also enhanced this activity. However, heat-inactivated L cell interferon and heterologous rabbit RK-13 cell interferon and human leukocyte interferon did not enhance it. This suggests that interferon enhances the bactericidal activity of macrophages against S. aureus.     

Phosphoinositide 3-kinase in nitric oxide synthesis in macrophage: critical dimerization of inducible nitric-oxide synthase

Phosphoinositide 3-kinase (PI3K) has important functions in various biological systems, including immune response. Although the role of PI3K in signaling by antigen-specific receptors of the adaptive immune system has been extensively studied, less is known about the function of PI3K in innate immunity. In the present study, we demonstrate that macrophages deficient for PI3K (p85alpha regulatory subunit) are impaired in nitric oxide (NO) production upon lipopolysaccharide and interferon-gamma stimulation and thus vulnerable for intracellular bacterial infection such as Chlamydophila pneumoniae. Although expression of inducible nitric-oxide synthase (iNOS) is induced normally in PI3K-deficient macrophages, dimer formation of iNOS protein is significantly impaired. The amount of intracellular tetrahydrobiopterin, a critical stabilizing cofactor for iNOS dimerization, is decreased in the absence of PI3K. In addition, induction of GTP cyclohydrolase 1, a rate-limiting enzyme for biosynthesis of tetrahydrobiopterin, is greatly reduced. Our current results demonstrate a critical role of class IA type PI3K in the bactericidal activity of macrophages by regulating their NO production through GTP cyclohydrolase 1 induction.     

Immunomodulating action of levamisole in influenzal infection in mice

The time of the activation of the regulatory lymphocyte subpopulation in the spleen and the influence of levamisole on the course of influenza infection in mice were studied in parallel. The study revealed that the final effect of the immunomodulating action of levamisole was determined by the concrete phase of the regulatory activity of lymphocytes. At the same time the injection of the preparation at the peak of helper activity induced a transitory decrease in antibody formation and, in the fatal form of the infection, a rise in the death rate among the animals. The probable role of levamisole-activated macrophages in the transitory suppression of immune response in mice during influenza infection is discussed.     

粘菌素对耐碳青霉烯类抗生素鲍曼不动杆菌的抗菌作用

感染耐碳青霉烯的鲍曼不动杆菌(CR-Ab)常与高发病率和死亡率相关联,而可供选择的治疗方案有限,大多基于与粘菌素联用。长期用药导致CR-Ab对粘菌素也产生一定抗性。为了评估含有或不含有粘菌素的不同抗菌组合对从CR-Ab感染患者收集的CR-Ab临床分离株的体外抗菌活性,本研究从本院就诊的患者中收集CR-Ab菌株,通过常量肉汤稀释法(MBD)测定最低抑菌浓度(MICs),通过定性(棋盘法)和定量(即杀菌测试)方法评估各组药物协同活性。结果发现所有菌株均是碳青霉烯类抗性的,且其中两株菌对粘菌素有抗性。棋盘法结果表明含粘菌素的组合在不同处理时间下具有完全协同作用,粘菌素+万古霉素和粘菌素+利福平表现出最高的协同增效作用;不含粘菌素的组合则在35.7%的菌株中观察到完全协同作用。杀菌测试表明粘菌素+美罗培南、粘菌素+替加环素和美罗培南+替加环素组合对粘菌素敏感和低粘菌素抗性的菌株具有杀菌和协同作用,而只有粘菌素+万古霉素和粘菌素+利福平组合表现出持久的杀菌活性。     

Lowering of bactericidal activity of mouse peritoneal macrophages under combined use of staphylococcal enterotoxin type A and endotoxin

The present study investigated the effect of staphylococcal enterotoxin type A (SEA) and endotoxin Serratia marcescens (LPS) on the phagocytosis and killing of Staphylococcus aureus by mouse peritoneal macrophages. Two hours after enterotoxin intraperitoneal injection phagocytic and bactericidal activity were depressed. 24 hours later there was increased functional activity of macrophages by SEA and LPS, apart. But when two toxins were administered together (LPS four hours later enterotoxin) marked inhibition of bacterial killing was observed. When peritoneal macrophages were treated in vitro for 24 hours with the same toxins they were also markedly suppressed in bactericidal activity.     

Study of the process of interaction of the causative agent with the cells of the body and with a macrophage culture in experimental typhoid infection and carrier state]

Experiments were conducted on 117 rabbits and cells of the macrophage cultures in vitro by the methods of clinico-laboratory, quantitative microbiological, immunological, electron microscopic and microcinematographic examination; a study was made of the interaction of the typhoid causative agent with the cells of the organism and the macrophage cultures and also of some aspects of the immune response during acute typhoid infection and carrier state. Infection was modelled by the enteral, subconjunctival and intrabonemarrow infection with 24-hour culture of the typhoid bacillus (strain Ty2 4446). Experiments demonstrated that structural reconstruction of both the causative agent and of the cells of the organism, of the culture macrophages and their organoids occurred in the course of the first hour after the infection. Homogenates of the lymphoid and myeloid tissues and also of the macrophages and polymorphonuclears possessed bactericidal activity against S. typhi. The degree of this activity largely depended on the pH of the medium. It was also shown that under conditions of the macrophage culture sodium aside inhibited the bactericidal activity of macrophages obtained from the intact and immune animals.     

Effect of pertussis vaccine on the functional activity of the peritoneal and splenic macrophages in 2 mouse strains genetically differing by the intensity of their immune response

The immunostimulating effect of corpuscular pertussis vaccine on the antigen-presenting and bactericidal functions of peritoneal and splenic macrophages in CBA and C57BL/6 mice, differing in the intensity of immune response to sheep red blood cells and Salmonella typhimurium, has been studied. The study has revealed that the injection of pertussis vaccine alters the functional activity of the cells under study, the effect depending on the immunizing dose, the strain of mice and the time elapsed from the moment of immunization. Pertussis vaccine enhances the low capacity of macrophages for antigen presentation in C57BL/6 mice with low responsiveness and alters the resistance of peritoneal and splenic macrophages to the cytopathic action of salmonellae.     

A Role for the ATP7A Copper-transporting ATPase in Macrophage Bactericidal Activity

Copper is an essential micronutrient that is necessary for healthy immune function. This requirement is underscored by an increased susceptibility to bacterial infection in copper-deficient animals; however, a molecular understanding of its importance in immune defense is unknown. In this study, we investigated the effect of proinflammatory agents on copper homeostasis in RAW264.7 macrophages. Interferon-γ was found to increase expression of the high affinity copper importer, CTR1, and stimulate copper uptake. This was accompanied by copper-stimulated trafficking of the ATP7A copper exporter from the Golgi to vesicles that partially overlapped with phagosomal compartments. Silencing of ATP7A expression attenuated bacterial killing, suggesting a role for ATP7A-dependent copper transport in the bactericidal activity of macrophages. Significantly, a copper-sensitive mutant of Escherichia coli lacking the CopA copper-transporting ATPase was hypersensitive to killing by RAW264.7 macrophages, and this phenotype was dependent on ATP7A expression. Collectively, these data suggest that copper-transporting ATPases, CopA and ATP7A, in both bacteria and macrophage are unique determinants of bacteria survival and identify an unexpected role for copper at the host-pathogen interface.     

Action of bioglycans from marine invertebrates on macrophage functioning

The data on the absorption and bactericidal function of macrophages are presented. It was shown in vivo that bioglycans 42 and 106 had a stimulating action on phagocytosis of Y. pseudotuberculosis and S. typhimurium capable of persisting in macrophages for prolonged periods. Addition of the bioglycans to the cultures of the macrophages from intact animals increased the absorption activity of the macrophages and somewhat potentiated their bactericidal activity. Under the action of the bioglycans the level and rate of the carbon clearance in the blood flow increased. The results of the study are promising for adequate control of infections caused by intracellularly located pathogens.     

Effect of antibiotics on Francisella tularensis]

The minimum inhibitory concentrations of rifampicin, doxycycline, sisomicin, ciprofloxacin and phosmidomycin for various strains of Francisella tularensis were 0.5 to 2.0, 0.5 to 2.0, 0.125 to 0.4, 0.625 to 0.125 and 2.0 to 12.5 micrograms/ml, respectively. Ciprofloxacin and sisomicin had a marked bactericidal effect. The bactericidal effect of rifampicin was insignificant. Doxycycline and phomidomycin had practically no such effect. All the antibiotics had a post effect. The level of the post-antibiotic effect was different and depended on the antibiotic concentration.     

Lysozyme-modified probiotic components protect rats against polymicrobial sepsis: role of macrophages and cathelicidin-related innate immunity

Severe sepsis is associated with dysfunction of the macrophage/monocyte, an important cellular effector of the innate immune system. Previous investigations suggested that probiotic components effectively enhance effector cell functions of the immune system in vivo. In this study, we produced bacteria-free, lysozyme-modified probiotic components (LzMPC) by treating the probiotic bacteria, Lactobacillus sp., with lysozyme. We showed that oral delivery of LzMPC effectively protected rats against lethality from polymicrobial sepsis induced by cecal ligation and puncture. We found that orally administrated LzMPC was engulfed by cells such as macrophages in the liver after crossing the intestinal barrier. Moreover, LzMPC-induced protection was associated with an increase in bacterial clearance in the liver. In vitro, LzMPC up-regulated the expression of cathelicidin-related antimicrobial peptide (CRAMP) in macrophages and enhanced bactericidal activity of these cells. Furthermore, we demonstrated that surgical stress or cecal ligation and puncture caused a decrease in CRAMP expression in the liver, whereas enteral administration of LzMPC restored CRAMP gene expression in these animals. Using a neutralizing Ab, we showed that protection against sepsis by LzMPC treatment required endogenous CRAMP. In addition, macrophages from LzMPC-treated rats had an enhanced capacity of cytokine production in response to LPS or LzMPC stimulation. Together, our data suggest that the protective effect of LzMPC in sepsis is related to an enhanced cathelicidin-related innate immunity in macrophages. Therefore, LzMPC, a novel probiotic product, is a potent immunomodulator for macrophages and may be beneficial for the treatment of sepsis.     

Mechanism of action of N-acetylglucosaminyl-N-acetylmuramylalanyl-D-isoglutamine on the nonspecific anti-infection resistance of mice

The stimulating influence of glucose-containing muramyldipeptide (GMDP) on the nonspecific resistance of mice was shown to depend on the features of the pathogenesis of the infection. Thus, the intraperitoneal injection of GMDP increased the survival rate of mice infected with Escherichia coli, but had no stimulating effect on the resistance of the animals to Salmonella typhimurium natural infection in whose pathogenesis macrophages played an essential role. Experiments demonstrated that GMDP was capable of enhancing the ingestive function of macrophages, but did not increase their bactericidal activity with respect to this infection.     

The in vitro bactericidal activity of peritoneal and spleen cells from Listeria-resistant and -susceptible mouse strains

Two days after Listeria-resistant (LrR) C57BL/10 mice were infected intraperitoneally with Listeria, their peritoneal macrophages demonstrated enhanced bactericidal activity beyond that seen in susceptible (LrS) BALB/c or CBA mice. Intravenous infection had no effect on peritoneal cell activity. The induction, but not expression, of the enhanced activity was radiosensitive. There was no significant difference between the strains with respect to the number of cells or cellular composition of the exudates. No difference in the in vitro chemotactic response of cells from the two strains could be demonstrated. Therefore there seems to be recruitment to the infected peritoneal cavity of C57BL/10 mice of young, efficiently bactericidal monocytes/macrophages. On the other hand, spleen cell bactericidal activity was intrinsically superior in C57BL/10 mice compared with BALB/c mice, possibly because, as a haemopoietic organ, the C57BL/10 spleen already contains high numbers of these efficient monocytes.