Number Of Bacteria In Blood Research Articles

Pectic Polysaccharides Isolated from Malian Medicinal Plants Protect against Streptococcus pneumoniae in a Mouse Pneumococcal Infection Model

The aim of this study was to investigate whether the pectic polysaccharides BP-II, Oc50A1.I.A and CC1P1 isolated from the Malian medicinal plants Biophytum petersianum, Opilia celtidifolia and Cola cordifolia, respectively, were able to protect against Streptococcus pneumoniae infection in mice. The pectin preparations were administered intraperitoneally 3h before challenge with S.pneumoniae serotype 6B. Blood samples were obtained from all animals before and at 3h, 24h and 72h after challenge with the pneumococci. The number of bacteria in blood was recorded and the blood concentration of a range of cytokines measured. The pretreatment with BP-II, Oc50A1.I.A and CC1P1 demonstrated a protective activity against S.pneumoniae serotype 6B infection, albeit at different range of concentrations. The pectins showed no direct antibacterial effects towards S.pneumonia; however, they induced the production of a range of cytokines and chemokines. We have previously shown that BP-II, Oc50A1.I.A and CC1P1 exhibit complement fixation activity and also that BP-II and Oc50A1.I.A stimulate macrophages to produce NO. The observed clinical effect might therefore be linked to the ability of the pectic polysaccharides to stimulate the innate immune system.

EFFECTS OF SPECIFIC NEUTROPHIL ELASTASE INHIBITOR, SIVELESTAT SODIUM HYDRATE, IN MURINE MODEL OF SEVERE PNEUMOCOCCAL PNEUMONIA

An excessive amount of neutrophil elastase (NE) released from neutrophils accumulated in the lung can cause tissue damage, despite its importance to host defense against microbial pathogens in severe pneumonia. Therefore, NE inhibitors may reduce tissue damage in lungs with severe pneumonia. In this study, the efficacy of a specific NE inhibitor, sivelestat sodium hydrate (sivelestat), was examined using a murine model of severe pneumonia with Streptococcus pneumoniae. Male mice (CBA/JNCrj, aged 5 weeks) were inoculated intranasally with penicillin-susceptible S. pneumonia (1.0 × 105 CFU/mouse). Sivelestat (3 mg/kg) or physiological saline was administered every 12 hours beginning at 12 hours after inoculation. Survival was primarily evaluated. Bronchoalveolar lavage fluid (BALF) and blood were collected at 30 hours after inoculation. Thus, cell counts in BALF and numbers of viable bacteria in blood were determined. Histopathological analysis was also performed. Sivelestat significantly prolonged survival when compared with the control group (P < .05), although all animals died within 4 days. Cell count and histopathological analysis indicated that sivelestat prevented the progression of lung inflammation, such as alveolar neutrophil infiltration and hemorrhage. Furthermore, the number of viable bacteria in blood was significantly lower in the sivelestat group than in the control group (5.69 ± 0.27 and 6.75 ± 0.32 log CFU/mL, respectively; mean ± SEM, P < .01). Sivelestat prolonged survival in this model. A possible explanation for the improved survival is that sivelestat prevents tissue damage by inhibiting NE activity in the lung. Therefore, NE inhibitors may be useful for treating with patients with severe pneumonia.

Prevalence of Bartonella clarridgeiae and Bartonella henselae in domestic cats from France and detection of the organisms in erythrocytes by immunofluorescence.

The prevalence of Bartonella infection in a pet cat population from France was found to be 8.1% (8 of 99 cats). The intraerythrocytic location of Bartonella clarridgeiae is shown for the first time, and we show that immunofluorescence detection of the organism in erythrocytes correlates with the number of bacteria in blood.

Induction of the anti-meningitis immunity with synthetic peptides. III. Immunoactive synthetic fragments of NspA protein from Neisseria meningitidis

Four potentially immunoactive peptide fragments of the NspA protein from the outer membrane of the bacterium Neisseria meningitidis were synthesized in order to create a synthetic vaccine against the meningococcal infection by the serogroup B bacterium. Mice of various lines were immunized with the free peptides nonconjugated with a protein carrier. All the synthetic peptides were shown to induce the production of the antipeptide antibodies in mice. A peptide capable of inducing a decrease in the number of bacteria in blood and the protection of infected animals from death was found in the experiments on the protection of the animals infected with two strains of the Neisseria meningitidis serogroup B. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2002, vol. 28, no. 4; see also http://www.maik.ru.

Typhoid fever in Bangladesh: implications for vaccination policy.

To describe the age-specific distribution of typhoid fever including the degree of Salmonella typhi bacteremia among patients evaluated at a large private diagnostic center in Bangladesh, a highly endemic area. We conducted a prospective-, passive- and laboratory-based study to identify patients with S. typhi bacteremia. Subjects (n = 4,650) from whom blood cultures were obtained during 16-month period were enrolled from private clinics and hospitals throughout Dhaka. Isolation and quantification of S. typhi from blood cultures were performed by the lysis direct plating/ centrifugation method. Bacterial pathogens were recovered from blood of 538 of 4,650 patients (11.6%) evaluated. S. typhi was the single most common pathogen recovered, comprising nearly three-fourths of isolates (72.7%; 391 of 538). Isolation rate of S. typhi was highest in monsoon and summer seasons and lowest in winter months. The majority (54.5%; 213 of 391) of S. typhi isolates were from children who were younger than 5 years, and 27% (105 of 391) were from children in the first 2 years of life. The isolation rate was highest (17.4%, 68 of 486) in the second year of life. The number of bacteria in blood on the basis of colony-forming units per ml of blood by age group was inversely related to age. Detection of S. typhi bacteremia in young children in Dhaka, Bangladesh, was considerably higher than previously appreciated, with a peak detection rate in children < or =2 years of age, indicating the need to reassess the age-specific burden of typhoid fever in the community on a regional basis. Contrary to current recommendations this study suggests that development of new vaccines should target infants and young children.

Quantitation of bacteria in bone marrow from patients with typhoid fever: relationship between counts and clinical features.

Enteric fever is the only bacterial infection of humans for which bone marrow examination is routinely recommended. A prospective study of the concentrations of bacteria in the bone marrow and their relationship to clinical features was conducted with 120 Vietnamese patients with suspected enteric fever, of whom 89 had confirmed typhoid fever. Ninety-three percent of the Salmonella enterica serovar Typhi samples isolated were resistant to ampicillin, chloramphenicol, and co-trimoxazole. For 81 patients with uncomplicated typhoid and satisfactory bone marrow aspirates, the number of serovar Typhi CFU in bone marrow aspirates was a median value of 9 (interquartile range [IQR], 1 to 85; range, 0.1 to 1,580) compared to 0.3 (IQR, 0.1 to 10; range, 0.1 to 399) CFU/ml in simultaneously sampled blood. The ratio of individual blood counts to bone marrow counts was 10 (IQR, 2.3 to 97.5). The number of bacteria in blood but not bone marrow was correlated inversely with the duration of preceding fever. Thus, with increasing duration of illness the ratio of bone marrow-to-blood bacterial concentrations increased; the median ratio was 4.8 (IQR, 1 to 27.5) during the first week compared with 158 (IQR, 60 to 397) during the third week. After lysing the host cells, the median ratio of viable bone marrow to blood increased, reflecting the higher concentration of intracellular serovar Typhi in the bone marrow. Effective antibiotic pretreatment had a significantly greater effect in reducing blood counts compared to bone marrow counts (P < 0.001). Thus, bacteria in the bone marrow of typhoid patients are less affected by antibiotic treatment than bacteria in the blood. The numbers of bacteria in bone marrow correlated negatively with the white blood cell (R = -0.3, P = 0.006) and platelet counts (R = -0.32, P = 0.01) and positively with fever clearance time after treatment (R = 0.4, P < 0.001). The bacterial load in bone marrow therefore may reflect the clinical course of the infection, and high levels may suppress neutrophil proliferation.

Protective effect of Plantago major L. Pectin polysaccharide against systemic Streptococcus pneumoniae infection in mice.

The antibacterial effect of a soluble pectin polysaccharide, PMII, isolated from the leaves of Plantago major, was examined in inbred NIH/OlaHsd and Fox Chase SCID mice experimentally infected with Streptococcus pneumoniae serotype 6B. Serotype 6B is known to give a more protracted infection when injected intraperitoneally into susceptible mice than more virulent serotypes like type 4. PMII was administered i.p. either once 3 days before challenge or once to thrice from 3 to 48 h after challenge. The number of bacteria in blood and the mouse survival rate were recorded. Pre-challenge administration of PMII and also lipopolysaccharide (LPS), included as a control, gave a dose-dependent protective effect against S. pneumoniae type 6B infection. However, injection of PMII after establishment of the infection in NIH/OlaHsd mice had no effect. The data demonstrate that, firstly, the polysaccharide fraction PMII from P. major protects against pneumococcal infection in mice when administered systemically prechallenge, and secondly that the protective effect is owing to stimulation of the innate and not the adaptive immune system.

Protective effect of subinhibitory polymyxin B alone and in combination with ampicillin for overwhelming Haemophilus influenzae type B infection in the infant rat: evidence for in vivo and in vitro release of free endotoxin after ampicillin treatment.

The potential endotoxin modifying effects of subinhibitory doses of polymyxin B were evaluated in an animal model of overwhelming septicemia. Five to six day old Sprague-Dawley rats were infected intraperitoneally with 10(6)-10(7) cfu of Haemophilus influenzae type b. At 12 h after infection, at which time mortality was 18%, subinhibitory doses of polymyxin b (0.0125 mg/kg X 3 q 3 h) either alone or in combination with 500 mg/kg ampicillin significantly increased survival at 17 and 20 h (p = 0.009, 0.01 and p = 0.003, 0.01) compared to animals treated with 0.5 mg/kg of ampicillin alone. Prolonged survival at 36 h (p = 0.009) was seen in animals receiving both ampicillin and low dose polymyxin compared to either ampicillin dose alone. Ampicillin significantly reduced the number of bacteria in blood of survivors (p less than 0.023 at 30 min) compared to untreated animals but increased the activity of free endotoxin at 30 min compared to controls (p = 0.006). In vitro endotoxin release from H. influenzae type b increased 5-fold after addition of 100 micrograms/ml of ampicillin, whereas a six-fold reduction in endotoxin activity was measured after the addition of 7 micrograms/ml of polymyxin B. Subinhibitory doses of polymyxin B modulate the ethal effects of overwhelming H. influenzae type b infection in infant rats and might be beneficial as adjunct treatment in gram-negative septicemia.

Experimental Pseudomonas pneumonia model in normal mice

Experimental Pseudomonas pneumonia was induced in normal mice by intratracheal inoculation of P. aerugionosa NC-5. The LD50 of this bacteria was 5.1×106 colony forming units per mouse.The number of bacteria in lungs increased without initial clearance after inoculation of 1×107 colony forming units per mouse and all mice died within 24-48 hours after inoculation.Bacetria appeared in the blood of pneumonia mice 6 hours after inoculation and the number of bacteria in blood increased gradually.Histopathological examination of pneumonia mice showed typical findings of Pseudomonas pneumonia with hemorrhage.The effect of antibiotics such as ceftazidime and gentamicin was evaluated using this murine Pseudomonas pneumonia.

STUDIES ON EXPERIMENTAL TYPHOID : THE DISTRIBUTION OF MICROORGANISMS IN THE COURSE OF INFECTION WITH S.ENTERITIDS AND THEIR PATHOIOGICAI STUDIES OF INFECTED MICE ORGANS

In the course of infection of mice with S.enteritidis, the distribution of microorganisms in the mice organs were studied. When the mice were infected with 10-7 and 10-5mg of virulent strain 116-54, the number of infected bacteria in the blood and liver was determined by stamp method.The results were shown in Fig. 2 and 3. 24 or 48 hours after the infection the number of bacteria in blood and liver decreased. But 3 days after the infection bacteria increased.The number of bacteria was also determined by plate counting method. As shown in Fig.4 and 5, the number of bacteria in the liver and blood decreased and reached minimum 6 hours after the infection. From this time the number of bacteria increased.The number of bacteria in 1 g of liver was always 100 times that in 1 ml of blood in the course of the infection.The histopathological studies of mice organs were described. The results were shown in figures.