Pseudomonas aeruginosa wound infection involves activation of its iron acquisition system in response to fascial contact.

BACKGROUND: Wound infections are traditionally thought to occur when microbial burden exceeds the innate clearance capacity of host immune system. Here, we introduce the idea that the wound environment itself plays a significant contributory role to wound infection. METHODS: We developed a clinically relevant murine model of soft tissue infection to explore the role of activation of microbial virulence in response to tissue factors as a mechanism by which pathogenic bacteria cause wound infections. Mice underwent abdominal skin incision and light muscle injury with a crushing forceps versus skin incision alone followed by topical inoculation of Pseudomonas aeruginosa. Mice were sacrificed on postoperative Day 6, and abdominal tissues were analyzed for clinical signs of wound infection. To determine if specific wound tissue components induce bacterial virulence, P. aeruginosa was exposed to the skin, fascia, and muscle. RESULTS: Gross wound infection caused by P. aeruginosa was observed to be significantly increased in injured tissues versus noninjured (80% vs.10%) tissues (n = 20 per group, p < 0.0001). Exposure of P. aeruginosa to individual tissue components demonstrated that fascia significantly induced bacterial virulence as judged by the production of pyocyanin, a redox-active phenazine compound known to kill immune cells. Whole-genome transcriptional profiling of P. aeruginosa exposed to the fascia demonstrated activation of multiple genes responsible for the synthesis of the iron scavenging molecule pyochelin. CONCLUSION: We conclude that wound elements, in particular fascia, may play a significant role in enhancing the virulence of P. aeruginosa and may contribute to the pathogenesis of clinical wound infection.

A case of brucellosis with abscess of the iliacus muscle, olecranon bursitis, and sacroiliitis.

Brucellosis is a systemic infection involving many organs and tissues. The musculoskeletal system is one of the most commonly affected. The disease can present with sacroiliitis, peripheral arthritis, spondylitis, paraspinal abscess, bursitis, and osteomyelitis. A 25-year-old male patient was admitted with fever of 20-day duration, right-sided hip pain, and night sweating. A Brucella standard tube agglutination test was positive at a titer of 1/160. Magnetic resonance imaging (MRI) of the hip joint showed right sacroiliitis and a hyperintense, nodular, lobulated mass within the right iliacus muscle, consistent with abscess. The patient was started on intramuscular streptomycin at a dose of 1 g/day, oral rifampin 600 mg/day, and doxycycline 200 mg/day. On day 20 of treatment, the patient was admitted with swelling and pain over the left elbow for the past week. MRI of the left elbow was performed, which showed fluid edema suggestive of olecranon bursitis. Taking the patient's complaints into consideration, rifampin and doxycycline treatment were maintained for a year. Pain at the hip joint and elbow resolved and MRI findings disappeared. Abscess of the iliacus muscle, which has not been reported before, and the olecranon bursitis that developed during treatment make this case worth presenting.

Pyomyositis: a diagnostic problem.

A case of a 45-year-old lady presenting with symptoms suggestive of pancreatitis is described. Initially the findings on Imaging were ambiguous while the enzyme studies were against the diagnosis of pancreatitis. Recurrence of symptoms and with Increased intensity prompted repeated imaging and further investigations. Finally, by a combination of CT scan, MR imaging and muscle biopsy the rare diagnosis of pyomyositis was established. The fact that this case was difficult to diagnose because of its rarity and its mimicking pencreatitis is discussed.

Primary anterior abdominal wall actinomycosis.

Actinomycosis of the anterior abdominal wall is rare. We report a 50-year-old diabetic man who presented with a left hypochondrial mass of three weeks duration associated with fever. Abdominal computed tomography showed a 2 x 4 cm mass projecting from the internal abdominal wall associated with surrounding inflammation. The mass did not decrease after a week of intravenous antibiotics. Excision of the mass and primary closure of the abdominal wall were performed. The mass involved the deep muscles of anterior abdominal wall. The omentum was adherent to the parietal peritoneum underneath the mass. Microscopical examination of the mass was consistent with actinomycosis. The postoperative period was uneventful and the patient recovered completely. The patient received penicillin for six months.

Protein carbonyl formation in the diaphragm.

Although protein carbonyl formation is an index of oxidative stress in skeletal muscles, the exact proteins, which undergo oxidation in these muscles, remain unknown. We used 2D electrophoresis, immunoblotting, and mass spectrometry to identify carbonylated proteins in the diaphragm in septic animals. Rats were injected with saline (control) or Escherichia coli lipopolysaccharides (LPS) and killed after various intervals. Diaphragm protein carbonylation increased significantly and peaked 12 h after LPS injection, and it was localized both inside muscle fibers and in blood vessels supplying muscle fibers. Aldolase A, glyceraldehyde 3-phosphate dehydrogenase, enolase 3beta, mitochondrial and cytosolic creatine kinases, alpha-actin, carbonic anyhdrase III, and ubiquinol-cytochrome c reductase were all carbonylated in septic rat diaphragms. In addition, we found significant negative correlations between the intensity of carbonylation and creatine kinase and aldolase activities. We conclude that glycolysis, ATP production, CO2 hydration, and contractile proteins are targeted by oxygen radicals inside the diaphragm during sepsis.

Necrotising fasciitis: a new management algorithm based on clinical classification.

Necrotising fasciitis is a rare infection of the subcutaneous tissues. If untreated, it is invariably fatal, and thus a high index of suspicion for the diagnosis is required. The disease's manifestation can range from a fulminant presentation to a subtle and insidious development. The priority in every case is to proceed to radical surgical debridement. On review of the literature and based on our clinical experience, we propose a new classification based on clinical presentation and suggest an algorithm to facilitate the management of this devastating condition. Increasing awareness should be given to the management of the large wounds resulting from the surgical debridement of necrotising fasciitis.

Prevalence and antimicrobial resistance pattern of Salmonella isolates from apparently healthy slaughtered cattle in Ethiopia.

The prevalence and antimicrobial resistance pattern of Salmonella isolates was determined from apparently healthy slaughtered cattle at Debre Zeit (Ethiopia). A total of 323 cattle were examined for the presence of Salmonella in faeces, mesenteric lymph nodes, abdominal and diaphragmatic muscles. Salmonellae were cultured from 23 (7.1%) of the animals. Salmonellae were isolated from 2 (3.1%) and 3 (4.5%) of 65 pooled faecal and mesenteric lymph node samples, respectively. Nine (2.8%) abdominal muscle and 10 (3.1%) diaphragmatic muscle samples (n = 323 of each) were contaminated by Salmonella. About 60% of the serovars identified in the abdominal and diaphragmatic muscles were also detected from faeces and mesenteric lymph node samples. The five different serovars isolated were Salmonella mishmarhaemek (48%) S. typhimurium (20%). S. enteritidis (12%), S. guildford (12%) and S. dublin (48%). The antimicrobial resistance profiles of 25 of the Salmonella isolates with 17 antimicrobials showed that 52%, (13/25) of them were resistant to three or more antimicrobials. Both strains of Salmonella (S. mishmarhaemek and S. typhimurium) showed multiple resistance to ampicillin, sulfamethoxazole and ticarcillin.

Group B streptococcal cellulitis in a child with steroid-responsive nephrotic syndrome.

Although infectious complications of nephrotic syndrome are common, group B Streptococcus is a rare pathogen in these patients. We present a 4-year-old child with nephrotic syndrome who developed group B streptococcal cellulitis and bacteremia, an association not previously discussed in the literature, and review the factors that predispose patients with nephrotic syndrome to infection.

Decreased systemic polymorphonuclear neutrophil (PMN) rolling without increased PMN adhesion in peritonitis at remote sites.

BACKGROUND: Previous in vitro studies have demonstrated that the host response to intra-abdominal infection produces increased generalized polymorphonuclear neutrophil (PMN) adherence to vascular endothelial cells (ECs), which may lead to subsequent endothelial damage, leaky capillaries, and organ dysfunction. There are scant data to demonstrate this enhanced systemic PMN adherence in vivo or the influence of PMN rolling on PMN endothelial adherence. HYPOTHESIS: Systemic PMN adherence in the animal with sepsis is increased. DESIGN: In vivo murine model of a 2-front infection using intravital microscopy of the cremasteric muscle to quantify PMN-EC adherence in a septic response. SETTING: Basic science laboratory and animal surgical facility. PATIENTS OR OTHER PARTICIPANTS: One hundred CD1 male mice. INTERVENTIONS: Animals underwent cecal ligation and puncture peritonitis, cremasteric muscle Escherichia coli infection, both infections, or neither (controls). Eighteen hours later, the mice underwent exteriorization of the cremasteric muscle under an intravital microscope for measurement of PMN-EC interactions. Blood was then drawn for calculation of circulating PMN counts. MAIN OUTCOME MEASURES: Adherence of PMNs, PMN rolling flux, PMN rolling velocity, and circulating PMN counts. RESULTS: Circulatory mechanics did not differ between the groups. Unlike static in vitro systems, we could not detect an increase in PMN adherence after peritonitis with this dynamic in vivo model. A local (cremasteric) infection was associated with marked PMN adherence. Peritonitis was associated with reduced PMN adherence at a local infection site as well as reduced rolling adhesion and PMN rolling velocity. CONCLUSIONS: The data suggest that intra-abdominal infection does not increase remote PMN adherence, and may actually result in reduction of systemic adherence via modulation of PMN rolling.

Postoperative necrotizing soft-tissue infections of the abdominal wall.

OBJECTIVE: The aim of the underlying study was the evaluation of an aggressive surgical regimen for treatment of postoperative necrotizing soft-tissue infection (NSTI). METHODS: Eight patients with postoperative NSTI of the abdominal wall after emergency (n=6) and elective (n=2) surgery were reviewed over a 9-year period. RESULTS: Initially, three patients presented with general peritonitis. Cultured swabs from the necrotic tissue revealed three to four different types of bacteria in each patient. The mean interval between the primary operation and clinical symptoms of NSTI was 63.0 h. Control of NSTI and intra-abdominal infection was attained by scheduled re-operations on a daily basis accounting for three to six re-interventions in each patient. Temporary closure of the abdominal wall by absorbable polyglactid-acid mesh was used in six cases. Mean hospital stay was 65.3 days (18-110 days). Two of the eight patients died from cardiac arrest and multiple organ failure, respectively. CONCLUSIONS: Rapid diagnosis and onset of treatment is accomplished by the surgeons' knowledge of this disease and a close follow-up of the patients in an intensive care unit.

Evaluation of iodophor skin preparation techniques and factors influencing drainage from ventral midline incisions in horses.

OBJECTIVE: To document natural bacterial flora on the ventral aspect of the equine abdomen, to compare 2 preparation techniques, and to identify potential risk factors that may contribute to incisional drainage. DESIGN: Prospective study. ANIMALS: 53 horses undergoing exploratory celiotomy. PROCEDURE: Group-1 horses (n = 26) were prepared with povidone-iodine and alcohol. Group-2 horses (27) were prepared with a film-forming iodophor complex. Numbers of bacterial colony-forming units (CFU) were measured before and after surgical scrub, following skin closure, and after recovery from general anesthesia. Swab specimens to identify normal skin bacterial flora and potential pathogens were obtained by swabbing a 4 x 4-cm area. Variables that might affect incisional drainage were also investigated. RESULTS: For both techniques, there was a significant reduction in bacterial numbers after skin preparation. Incisional drainage was observed in 14 (26%) horses (8 group-1 and 6 group-2 horses). Preexisting dermatitis, poor intraoperative drape adherence, high number of bacterial CFU obtained after recovery from anesthesia, and high number of CFU obtained from the surgery room environment were the main risk factors associated with subsequent incisional drainage. Bacillus spp, nonhemolytic Staphylococcus spp, Micrococcus spp, Corynebacterium spp, Streptomyces spp, other nonenteric genera, and nonhemolytic Streptococcus spp were the most common isolates obtained before surgical scrub. CONCLUSIONS AND CLINICAL RELEVANCE: Both skin preparation techniques were equally effective in reducing numbers of bacterial CFU by 99%, and a significant difference was not found in incisional drainage rate between groups. Protection of the wound during recovery from anesthesia and the immediate postoperative period may reduce incisional drainage after abdominal surgery in horses.

Concentrations of prophylactic ceftriaxone in abdominal tissues during pancreatic surgery.

Ceftriaxone concentrations in abdominal tissues were evaluated after administration as antibiotic prophylaxis for pancreatic surgery. Ten patients were given ceftriaxone (1 g i.v.) 30 min before surgery. Ceftriaxone concentrations in fatty tissues ranged from 2.5 to 6.2 microg/g. Ceftriaxone concentrations were 6.0 +/- 8.6 microg/g in pancreatic tissues, 2.1 +/- 2.5 mg/L in pancreatic fluid, 1179 +/- 1271 mg/L in pancreatic bile, and 18 +/- 16 microg/g in the liver. In fatty tissues, 8-10 patients had tissue levels greater than the MIC90 for Staphylococcus aureus and Escherichia coli and the 10 patients had tissue levels greater than the MIC90 for Klebsiella pneumoniae and Proteus mirabilis. In other tissues, penetration was greater than the MIC90 for potential pathogens in 50-100% of the patients.

Clostridium septicum infection in children with cyclic neutropenia.

Atraumatic Clostridium septicum infection is rare in infancy and childhood and is associated with a high mortality rate. Although in adults it has been reported to occur mainly in patients with gastrointestinal malignancy, pediatric cases were always associated with neutropenia. About 70% of the cases were described in children with neutropenia caused by chemotherapy and 30% were found in children with cyclic neutropenia. No case was described in children with other forms of congenital severe neutropenia. We describe three children with cyclic neutropenia and severe Clostridium septicum infection, discuss the various possibilities of causation, and the need for prompt and aggressive treatment of this serious condition.

[Development of an experimental rat model of intraabdominal abscess by Escherichia coli alone. II. Interactions between an intraabdominal abscess and a host].

It has been demonstrated that an intraabdominal abscess by Escherichia coli alone can be developed without fail although anaerobes or barium sulfate are not used. We investigated the properties and the influence of this abscess on the host. We took the method of bacterial implantation by insertion of a double gelatin capsules containing Escherichia coli suspension of which concentration was adjusted to five grades into the peritoneal cavity of Wister rats. Abscesses were developed in the survived rats on which live bacteria had been inoculated. Only Escherichia coli were found in these abscesses by culture whereas no death was occurred and no abscess was developed in the rats on which no bacterium or heat-killed ones had been inoculated. As for non-survivors at the 7th postoperative day, all of them died of panperitonitis and no abscess was developed. An abscess was developed without fail when live bacteria of which number within the order of 10(7) colony forming units were inoculated. Blood endotoxin concentration 24 hours after inoculation increased exponentially according to the inoculum size. However, that at the 7th postoperative day returned to the levels at zero time. Microscopic examination revealed a thick abscess wall, poor infiltration of inflammatory cells, and poor neovascularsis into the wall. These findings suggest that endotoxin is prevented from release into the blood stream since abscess contents are isolated by thick wall.

Clostridial gas gangrene of the abdominal wall after laparoscopic cholecystectomy.

Laparoscopic cholecystectomy is associated with a considerable rate of infectious complications of up to 2.8%. Such infections are usually of minor clinical importance. However, we observed a case of life-threatening Clostridial gas gangrene centering around the right lateral port site and developing across all of the right-sided abdominal wall, causing septic shock and severe multi-organ failure. Considering the overall infection rate and the possibility of even severe morbidity, we advocate perioperative antibiotics in laparoscopic cholecystectomy.

Botriomicose: relato de um caso / Botryomycosis: a case report

Os autores relatam um caso de botriomicose com tumoração da parede abdominal anterior. Ela é de origem bacteriana e acomete tanto o tecido cutâneo quanto o visceral, e a áreas expostas como mãos e pés são as mais atingidas. No caso em questão se estendia por toda a parede abdominal anterior, com trajetos fistulosos, comprometendo o tecido subcutâneo, músculos, gordura pré-peritoneal, não havendo planos de clivagem com alças instestinais, atingindo região pancreática e bexiga. O diagnóstico final foi feito por exame histopatológico e bacteriológico da lesão.

Laparostomía contenida: experiencia de 10 años / Contained laparostomy: 10 years experience

La laparostomía contenida es una técnica quirúrgica de excepción indicada especialmente en sepsis abdominal y de pared cuyos objetivos son facilitar evacuación de focos sépticos residuales, minimizando así los efectos sistémicos de la sepsis y evitar el trauma y necrosis de la pared por cierres iterativos. Esta es una técnica aún vigente, pero que dada su alta morbimortalidad debe ser manejada en centros con recursos humanos y materiales adecuados para la gravedad de estos pacientes