Acute Staphylococcal Infection Research Articles

α-Toxin Induces Platelet Aggregation and Liver Injury during Staphylococcus aureus Sepsis

During sepsis, small blood vessels can become occluded by large platelet aggregates of poorly understood etiology. During Staphylococcal aureus infection, sepsis severity is linked to the bacterial α-toxin (α-hemolysin, AT) through unclear mechanisms. In this study, we visualized intravascular events in the microcirculation and found that intravenous AT injection induces rapid platelet aggregation, forming dynamic micro-thrombi in the microcirculation. These aggregates are retained in the liver sinusoids and kidney glomeruli, causing multi-organ dysfunction. Acute staphylococcal infection results in sequestration of most bacteria by liver macrophages. Platelets are initially recruited to these macrophages and helperadicate S. aureus. However, at later time points,AT causes aberrant and damaging thrombosisthroughout the liver. Treatment with an AT neutralizing antibody (MEDI4893∗) prevents platelet aggregationand subsequent liver damage, without affecting theinitial and beneficial platelet recruitment. Thus,AT neutralization may represent a promising approach to combat staphylococcal-induced intravascular coagulation and organ dysfunction.

A novel CCR-2/TLR-2 triggered signaling in murine peritoneal macrophages intensifies bacterial (Staphylococcus aureus) killing by reactive oxygen species through TNF-R1

Macrophages are remarkably versatile in their ability to recognize and respond to a wide range of stimuli by expressing a variety of surface and intracellular receptors and triggering multiple signal transduction pathways. The onset of microbial infection is primarily determined by the initial contacts made by the microbes with the host macrophages. Although there prevail a relationship between the chemokine receptor and Toll like receptors during disease, particularly TLR-2 and CCR-2 signaling interdependence on each other has not been yet investigated during acute staphylococcal infection. Thus, the present study was aimed to trace possible interaction between CCR-2 and TLR-2 in peritoneal macrophages during acute Staphylococcus aureus infection. We found that neutralization of CCR-2 attenuates TLR-2 expression and restricts S. aureus burden but TLR-2 neutralization augments CCR-2 expression in macrophages, along with compromised host-derived reactive oxygen species production. S. aureus infection to CCR-2 intact but TLR-2 neutralized macrophages triggered production of IL-1β, TNF-α, IL-6, IFN-γ, MCP-1 and expression of iNOS, TNFR-1 and GPx with concomitant decrease in IL-10 production. Further, study with NG-monomethyl-l-arginine (L-NMMA) [iNOS blocker] and buthionine sulfoximine (BSO) [GPx blocker] revealed that S. aureus infection enhanced TLR-2 expression in CCR-2 intact and TLR-2 neutralized macrophages possibly via iNOS and TNFR-1 up regulation and GPx down regulation. Overall, our data indicate that targeting CCR-2 with neutralizing antibody in the early phase of S. aureus infection could restrict excessive inflammation with less compromised bacterial killing. It certainly would be a therapeutic strategy in S. aureus induced inflammatory and infective diseases.

Infections after Anterior Cruciate Ligament Reconstruction: Which Antibiotic after Arthroscopic Debridement?

Arthroscopic debridement has proven to be the optimal surgical treatment for infections of the anterior cruciate ligament reconstruction (ACLR). Nevertheless, there are no reported data for the best antibiotic treatment option and its duration. The purpose of this article is to assess the usefulness of oral levofloxacin and rifampicin for the treatment of acute infections of an ACLR. This is a retrospective observational cohort study of patients operated on for ACLR over 4 years. A diagnosis of septic arthritis was based on patients' anamnesis and physical examination, laboratory parameters, and cultures of synovial fluid and/or joint tissue. Arthroscopic lavage was performed as soon as possible and tissue samples were taken. At a minimum 2-year follow-up, the infection was considered cured with a normal C-reactive protein (CRP) level and a correctly functioning and pain-free knee. Of the 810 patients, 15 (1.8%) were diagnosed as having an infection. Among the 13 staphylococcal cases (86.6%), 10 were susceptible to both quinolones and rifampicin (76.9% of the staphylococcal infections). There were two staphylococci that were rifampicin resistant. In the remaining one case, the coagulase-negative staphylococcus (CNS) was resistant to quinolones. One CNS infection was treated with linezolid and rifampicin and was the only case that needed graft removal due to treatment failure. Antibiotic treatment lasted an average of 6 weeks and oral treatment started at a mean of 5 days (range, 4-7). In the remaining 12 patients, CRP levels returned to normal at a mean of 3 weeks with good knee function and no local symptoms. Staphylococci (especially CNS) are responsible for almost 90% of acute ACLR infections in the current series. For the first time, the combination of levofloxacin and rifampicin is being proposed as a treatment in cases of an acute staphylococcal infection of an ACLR. An early switch to oral antibiotic treatment (as soon as the cultures are available) with both levofloxacin and rifampicin for a total (empiric and directed) period of 6 weeks should be considered as treatment of choice in acute staphylococcal infections of the ACLR with a retained graft. The level of evidence is IV (case series).

Intracellularly survived Staphylococcus aureus after phagocytosis are more virulent in inducing cytotoxicity in fresh murine peritoneal macrophages utilizing TLR-2 as a possible target

Staphylococcus aureus with high virulence potential is contributing to a current public health crisis in both hospital and community settings. TLR-2 and generation of reactive oxygen species (ROS) by phagocytic cells is thought to be an important component of the host's immunity against S. aureus infection. However, response of S. aureus against modulation of host-derived ROS in absence of TLR-2 during acute staphylococcal infection is still remains unclear. Peritoneal macrophages were pretreated with either inhibitors of superoxide dismutase (SOD) or catalase in presence or absence of anti TLR-2 antibody and were infected with S. aureus strain AG-789. Bacteria were recovered after time dependent phagocytosis; intracellular killing, level and expression of SOD and catalase were measured. Phagocytosed bacteria from respective groups were further used for infection to fresh peritoneal macrophages as well as for invivo infection. Levels of ROS, cytokine, lysozyme, antioxidant enzymes activity and TLR-2 expression were measured. Results revealed that more bacteria were escaped killing in SOD and catalase inhibitor pretreated TLR-2 neutralized macrophages, found to express more catalase and are antibiotic resistant. Infection of fresh macrophages with S. aureus, recovered from SOD and catalase inhibited TLR-2 neutralized macrophages induced lower ROS, lysozyme and cytokine production and caused increased bacterial count. Furthermore, bacterial antioxidants by modulating host-derived ROS could regulate the cell surface TLR-2 expression in murine peritoneal macrophages. So, in the early phase of infection, TLR-2 participates in the innate immune response and targeting bacterial antioxidants might be useful in the alleviation of Staphylococcus aureus infection.

Host antioxidant enzymes and TLR-2 neutralization modulate intracellular survival of Staphylococcus aureus: Evidence of the effect of redox balance on host pathogen relationship during acute staphylococcal infection

Staphylococcus aureus is an important pathogen in bone disease and innate immune recognition receptor, TLR-2 is reported to be crucial for inflammatory bone loss. Role of TLR-2 in bacterial clearance and cytokine response to S. aureus infection in murine bone marrow macrophages has been reported but the role of host derived ROS in host-pathogen relationship still remains an obvious question. In the present study, blocking of SOD and catalase in TLR-2 neutralized fresh bone marrow cells (FBMC) with Diethyldithiocarbamic acid (DDC) and 3-Amino-1,2,4-triazole (ATZ), separately, during acute S. aureus infection, produces moderate level of ROS and limits inflammation as compared with only TLR-2 non-neutralized condition and leads to decreased bacterial count compared with only TLR-2 neutralized condition. In summary, host SOD and catalase modulates ROS generation, cytokine levels and TLR-2 expression in FBMCs during acute S. aureus infection which might be useful in the alleviation of S. aureus infection and bone loss.

Staphylococcal Infections

Staphylococcal Infections

Staphylococcal Infections

Staphylococcal Infections

Acute hematogenous staphylococcal infections involving upper-extremity musculotendinous compartments: Report of 2 cases

Two unusual cases involving 2 patients with 3 hematogenously spread acute staphylococcal infections that occurred in musculotendinous compartments and required surgical debridement are reported. Infections that persist despite intravenous administration of antibiotics may indicate rare closed-space infections.

Acute staphylococcal infections in rabbits irradiated with 3-GHz microwaves.

Annals of the New York Academy of SciencesVolume 247, Issue 1 p. 305-311 ACUTE STAPHYLOCOCCAL INFECTIONS IN RABBITS IRRADIATED WITH 3-GHz MICROWAVES* S. Szmigielski, Corresponding Author S. Szmigielski Institute of Aviation Medicine and National Institute of Hygiene Warsaw, Poland†Correspondence address: 11/3 Pulawska, 02-515 Warsaw, Poland.Search for more papers by this authorJ. Jeljaszewicz, J. Jeljaszewicz Institute of Aviation Medicine and National Institute of Hygiene Warsaw, PolandSearch for more papers by this authorMarzenna Wiranowska, Marzenna Wiranowska Institute of Aviation Medicine and National Institute of Hygiene Warsaw, PolandSearch for more papers by this author S. Szmigielski, Corresponding Author S. Szmigielski Institute of Aviation Medicine and National Institute of Hygiene Warsaw, Poland†Correspondence address: 11/3 Pulawska, 02-515 Warsaw, Poland.Search for more papers by this authorJ. Jeljaszewicz, J. Jeljaszewicz Institute of Aviation Medicine and National Institute of Hygiene Warsaw, PolandSearch for more papers by this authorMarzenna Wiranowska, Marzenna Wiranowska Institute of Aviation Medicine and National Institute of Hygiene Warsaw, PolandSearch for more papers by this author First published: February 1975 https://doi.org/10.1111/j.1749-6632.1975.tb36006.xCitations: 21 * Supported by Research Grant 05-327-2 from the United States Public Health Service. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume247, Issue1Biologic Effects of Nonionizing RadiationFebruary 1975Pages 305-311 RelatedInformation

ANTIBODIES AGAINST STAPHYLOCOCCAL BACTERIOPHAGES IN HUMAN SERA

Sera from healthy individuals and from patients with staphylococcal infections were examined for anti‐alpha‐lysin and for antibodies against staphylococcal phage antigens. The phage antigens consisted of purified phages of the serological groups A, B and F, which were adsorbed to tanned sheep erythrocytes. In healthy individuals elevated antibody titres against each of the phage antigens were found in 9–11 per cent and elevated ASta‐titres in 1 per cent. Elevated titres against phage antigen group A were found in 71 per cent of the patients. The corresponding figures for antigen group B and F were 25 and 47 per cent, respectively. Elevated ASta‐titres were found in 44 per cent of the patients. A four‐fold rise of the antiphage antibody titre could occur within 6–14 days in patients with acute staphylococcal infections.

A cytospectrophotometric study of some reactions occuring in the lymphocyte nucleus during acute staphylococcal infection in the guinea-pig.

This work follows the modifications occuring in the chemistry of the nuclear material of guinea-pig neutrophile and lymphocyte series during septical (Staphylococcus aureus) and aseptical inflammation. These changes have been investigated qualitatively by means of cytospectrophotometry in the visible range, to which end smears have been collected from the blood-stream at zero, 1, 3, 5, 9 and 12 days after initiating the infection, then stained by theGiemsa method adapted to cytospectrophotometry in the visible range.

Antistaphylocoagulase in Experimental Staphylococcal Infections

Summary A study has been made of the effects of anti-staphylocoagulase in acute staphylococcal infections of rabbits and mice. Rabbits actively immunized with coagulase were more resistant to intravenous challenge with coagulase-positive, but not coagulase-negative staphylococci. When mice were injected intraperitoneally with coagulase-positive staphylococci suspended in a clotting system (fibrinogen/co-factor), serum from rabbits immunized with coagulase diminished the virulence of these staphylococci provided it was allowed to come into contact with the challenge organisms for 30 minutes before the addition of the clotting system. The virulence of the organisms was also diminished under the same conditions by human serum containing coagulase-inhibiting antibodies. This diminution of virulence was not produced by alpha antitoxin or staphylococcal agglutinating serum, and was not demonstrable against coagulase-negative staphylococci. It is considered that the diminution of virulence observed in mice was due to the in vitro inhibition of coagulase activity, and that the active immunity observed in rabbits was probably associated with in vivo inhibition of coagulase activity.

FURTHER OBSERVATIONS ON ACUTE STAPHYLOCOCCAL INFECTION

Journal Article FURTHER OBSERVATIONS ON ACUTE STAPHYLOCOCCAL INFECTION Get access E. C. B. Butler, E. C. B. Butler Search for other works by this author on: Oxford Academic PubMed Google Scholar F. C. O. Valentine F. C. O. Valentine Search for other works by this author on: Oxford Academic PubMed Google Scholar British Medical Bulletin, Volume 1, Issue 4, June 1943, Page 48, https://doi.org/10.1093/oxfordjournals.bmb.a070176 Published: 01 June 1943

Acute Staphylococcal Infections of the Kidney

Acute Staphylococcal Infections of the Kidney