Murine model of recurrent group G streptococcal cellulitis: no evidence of protective immunity

Despite the well-known tendency of cellulitis due to beta-hemolytic streptococci to recur, little is known regarding the mechanisms of human immunity to this infection. We established cellulitis in mice by using a strain of group G streptococcus (1750) originally isolated from the bloodstream of a patient with acute cellulitis. This strain, which has been studied extensively in our laboratory, expresses M protein structurally and functionally analogous to that of group A streptococci, and we have cloned and sequenced the gene encoding this protein (emmMG1). Mice injected with 5 x 10(7) CFU of strain 1750 developed nonlethal necrotic skin and soft tissue infections that healed spontaneously after 14 to 16 days. After healing, the mice were repetitively reinoculated three times with the same challenge dose of 1750. Lesion size did not decrease in severity, size, or time to healing after repetitive challenge. The maximum lesion size and tissue concentration of microorganisms increased between the first and fourth challenges. Pretreatment of 1750 cells with opsonic antisera to MG1 diminished neither the maximum lesion size nor the time course of evolution of the lesions. Thus, in the mouse model used here, there was no evidence of acquired protective immunity to experimentally induced cellulitis.     

Invasive streptococcal infection as a complication of chickenpox

Two girls aged 11 months and 6 years, presented with an invasive group A streptococcal (GAS) infection during the course of primary varicella. The infant had severe cellulitis of the left arm and leg, fever and bacteraemia. She developed osteomyelitis of ulna and tibia. The 6-year-old girl had a fever > 38.5 degrees C, hypotension, an acute respiratory distress syndrome, liver function abnormalities, and positive cultures of blood and joints. Her clinical picture was compatible with a GAS-associated toxic shock syndrome. If during the course of primary varicella persistent fever, secondary fever or pain in one or more extremities occurs, invasive bacterial infection by GAS or Staphylococcus aureus should be considered, even in the absence of skin infection or cellulitis.     

Preseptal and orbital cellulitis in childhood. A changing microbiologic spectrum

OBJECTIVE: The authors sought to determine whether the microbiologic spectrum of preseptal and orbital cellulitis had changed over the past decade. DESIGN: A retrospective chart review of all inpatient and outpatient children with an ICD-9 diagnosis of preseptal or orbital cellulitis seen at Vanderbilt University Medical Center since the introduction of the Haemophilus influenzae type-B (HiB) vaccine (1986-1996). MAIN OUTCOME MEASURES: Blood and abscess cultures from children with preseptal and orbital cellulitis were tabulated. RESULTS: During this period, 70 cases of preseptal cellulitis were seen. Blood cultures were obtained in 59 cases; only 6 were positive. Five cultures grew Streptococcus species. The one positive H. influenzae culture occurred in 1987 in a child who did not receive the HiB vaccine. There have been no new patients with preseptal cellulitis and H. influenzae bacteremia at Vanderbilt for 10 years. There were ten cases of orbital cellulitis, of which blood or abscess or both were cultured in eight. Six cases had positive cultures. Four cultures grew Streptococcus species. The other two grew H. influenzae and mixed H. influenzae/gram-positive cocci. CONCLUSION: The incidence of hemophilus-associated bacteremia in patients with preseptal cellulitis has decreased dramatically over the past 10 years. Streptococcus species now are the predominant cause. Orbital cellulitis due to H. influenzae may still occur, but it is much less likely. A more conservative approach to the diagnosis and management of preseptal and orbital cellulitis may be warranted.     

Microbiology of perianal cellulitis in children: comparison of skin swabs and needle aspiration

OBJECTIVE: To establish the aerobic and anaerobic microbiology of perianal cellulitis in children, comparing skin swab and needle aspirate methodology. METHOD: Swabs of involved skin and needle aspirates of cellulitis were studied for aerobic and anaerobic bacteria. RESULTS: Specimens obtained from 10 patients with perianal cellulitis showed bacterial growth. Polymicrobial aerobic-anaerobic flora was found in all skin surface cultures, where the predominate isolates were Peptostreptococcus spp., Escherichia coli, and alpha hemolytic streptococci. The number of isolates in needle aspirates varied between one and two. The predominant ones were E. coli (3), Peptostreptococcus spp. (3), Staphylococcus aureus (2), and Bacteroides fragilis group (2). Complete or partial concordance in microbiology between skin swabs and needle aspirates was present in six instances. In four instances, isolates recovered from needle aspirates were not isolated from the skin surface. CONCLUSIONS: This study demonstrates the diversity of aerobic and anaerobic organisms isolated from perianal cellulitis, and the superiority of needle aspirates in establishing the microbiology of the infection.     

Analysis of proprioception in the posterior cruciate ligament-deficient knee

Preseptal cellulitis has a typically benign course when treated with antibiotics, the clinical course depending on age of the patient, aetiology and the causative organism. In this study, 14 cases of preseptal cellulitis are documented with the age ranging from 2 to 55 years. The organisms isolated were Staphylococcus aureus (7 cases), Streptococcus pyogenes (2 cases) and Pseudomonas aeruginosa (1 case). In the remaining four patients no organism could be identified. All except four patients were cured within 6 weeks. Complications seen included lagophthalmos, lid abscess, cicatricial ectropion and lid necrosis in one patient each. The prognosis for preseptal cellulitis is good with appropriate antibiotics and surgical therapy.     

An international evaluation of the cancer-preventive potential of nonsteroidal anti-inflammatory drugs

The most common complication in children with varicella is cutaneous superimposed infection with pyogenic bacteria. Group A beta-hemolytic streptococci, which are known to cause life-threatening infections in both previously healthy children and those with underlying diseases, are the most frequently associated pathogens. A newly recognized disease, called streptococcal toxic shock syndrome, is associated with severe morbidity and mortality. We report a 3-year-old boy with a diagnosis of this syndrome who presented with increasing fever, vomiting, and lethargy 7 days after the development of a classic varicella skin lesion. In spite of aggressive fluid supply, administration of inotropic agents, and cardiopulmonary resuscitation, a rapidly deteriorating clinical course led to death 4 hours after hospitalization. This is the first report of this association in Taiwan. Pediatricians evaluating children with varicella must be mindful of the potential for Group A beta-hemolytic streptococcal infection.     

Streptococcal pyomyositis: case report and review

Pyomyositis is most often associated with Staphylococcus aureus infections after trauma. We describe an unusual presentation of pyomyositis of the chest wall secondary to group A betahemolytic streptococcus infection in a 15-month-old child with acute abdominal symptoms. In addition, the patient had no history or evidence of trauma to the affected area. Pyomyositis presenting in this manner secondary to group A beta-hemolytic streptococcus infection in the absence of a primary varicella infection has not been previously reported.     

Necrotizing group A streptococcal infections associated with streptococcal toxic shock syndrome

BACKGROUND: Group A streptococci (GAS) cause a variety of life-threatening infectious complications, including necrotizing fasciitis (NF), purpura fulminans (PF), and streptococcal toxic shock syndrome (strepTSS), in which bacteremia is associated with shock and organ failure. METHODS: We reviewed our experience in the management of patients with necrotizing GAS infections from 1991 to 1995. RESULTS: Eight adult patients (6 NF, 2 PF) were identified. Patients presented with fever, leukocytosis, and severe pain, and rapidly developed shock and organ dysfunction. The diagnosis of strepTSS was confirmed in 6 cases. A total of 54 surgical procedures were required, including widespread debridements and amputations. Two patients died (25%). CONCLUSIONS: Recognition of the need for aggressive diagnosis and surgical treatment of this most rapidly progressive surgical infection is necessary for successful management.     

The effect of empiric and prophylactic treatment with fluconazole on yeast isolates in a surgical trauma intensive care unit

OBJECTIVE: To assess the effect of aggressive antifungal prophylaxis and empiric antifungal therapy using fluconazole on the mycotic microbiology and associated infectious complications in a surgical intensive care unit. DESIGN: Retrospective review of a cohort of critically ill surgical patients treated during an 11-month period. SETTING: Surgical intensive care unit, university hospital, state-designated level I trauma center. PATIENTS: All patients treated with fluconazole during the study. MAIN OUTCOME MEASURES: Positive fungal cultures obtained after commencement of antifungal prophylaxis or antifungal treatment with fluconazole. Overall and infectious mortality rates for patients with positive cultures were also measured. RESULTS: Of 72 surgical patients who were treated with fluconazole; 16 (22%) had secondary mycoses. Fourteen (88%) of these patients were receiving fluconazole as antifungal prophylaxis or as empiric treatment of suspected but unproved infection. The predominant organisms isolated from these 16 patients were Candida glabrata (41%) and Candida parapsilosis (41%). Overall mortality for this group was 44%, and infectious mortality was 38%. The infectious mortality rate was significantly higher than the rate found in patients who were successfully treated with fluconazole for primary mycoses, and who did not have secondary infections with resistant organisms (mortality, 9%; P < .01, chi 2). CONCLUSIONS: Emergence of resistant species after treatment with fluconazole does occur in surgical patients, and suggests that the development of a secondary fungal infection with a resistant organism may be associated with a poor prognosis.     

Familial transmission of a serious disease--producing group A streptococcus clone: case reports and review

Invasive group A streptococcus (GAS) infections are emerging diseases; however, person-to-person transmission of invasive GAS producing life-threatening infection has been observed rarely. We report a small intrafamilial cluster of life-threatening GAS infections. A previously healthy 47-year-old father developed necrotizing fasciitis of the neck. Two days later, his 16-year-old daughter developed streptococcal angina, pneumonia, and pleural empyema. Both patients had signs of streptococcal toxic shock syndrome. Pulsed field gel electrophoresis revealed that the M6 strains of GAS isolated from the father and daughter had identical patterns. Cases of person-to-person transmission of invasive GAS infection reported in the literature are also reviewed.     

Clinical features of primary and secondary atypical mycobacteriosis

A clinical investigation was carried out in 39 patients with atypical mycobacteriosis (AM). The patients at our hospital diagnosed as having AM during an 11-year period from 1981 to 1991 were reviewed in this study. The incidence of AM among all of mycobacterial infections has been increasing since 1988. The atypical mycobacteria detected included M. avium complex (MAC) in 79%, M. kansasii in 26%, and other organisms in 5%. Patients who had primary infection without underlying respiratory disease were compared with those who had secondary infection. In secondary infection, MAC was detected in the sputum of a high percentage of patients and was positive for more than 6 months despite therapy. Gamma globulin levels were also increased in patients with secondary infection. Cell mediated immunity was examined by the DNCB reaction and the detection of CD4- and CD8- positive T lymphocytes. The DNCB skin reaction was positive in 6 out of 26 patients with secondary infection. The percentage of CD8- positive T lymphocytes was higher in patients with secondary disease. Fischer's ratio (indicating the balance of plasma amino acids) was also examined as an index of the nutritional status. It was significantly lower in secondary infection compared with primary infection. Moreover, secondary infection was associated with a lower positive rate for the DNCB skin reaction and a lower Fischer's ratio when compared with pulmonary tuberculosis. Thus impairment of cell-mediated immunity, malnutrition, and a poor prognosis were significantly more common in secondary infection compared with primary infection.     

Anterior capsulotomy created by radiofrequency endodiathermy and continuous curvilinear posterior capsulorhexis in a patient with intumescent cataract and primary capsular fibrosis

PURPOSE: To report a clinicopathologic correlation of angiosarcoma affecting the eyelid skin. METHODS: An 82-year-old man developed multiple bruise-like maculopapular lesions, subcutaneous nodules, and diffuse edema over his scalp, face, and eyelids. Biopsy disclosed angiosarcoma, and the patient was treated with wide-field external beam radiotherapy (5,000 cGy). RESULTS: He responded to radiotherapy with partial regression of the tumor. Twelve months later, he developed extensive lymphedema secondary to the residual tumor. He was also found to have parotid gland and bone metastases, treated with radiotherapy. The patient died of widespread bone metastases 3 months later. CONCLUSIONS: Angiosarcoma is a rare skin tumor that has a poor prognosis despite treatment. It should be considered in the differential diagnosis of eyelid tumors and edema because it may affect only the central portion of the face.     

Heterotopic ossification as a complication of toxic epidermal necrolysis

The development of heterotopic ossification (HO) as a complication of toxic epidermal necrolysis (TEN) has not been previously reported. TEN, also known as Lyell's syndrome, is a rare but serious skin disorder that typically occurs after the administration of drugs, especially sulfonamides, barbiturates, phenytoin, and nonsteroidal anti-inflammatory agents. TEN is characterized by the development of large fluid-filled bullae with separation of large sheets of skin. Complications of TEN can include extensive denudation of skin with dehydration and electrolyte abnormalities, gastrointestinal hemorrhage, acute tubular necrosis, secondary infection of denuded skin, pneumonia, bacterial conjunctivitis, keratitis, and septic infarcts of internal organs. We report a case of HO in a patient with TEN after treatment with trimethoprim-sulfamethoxazole. A 49-year-old man developed an erythematous rash, bullae, fever, and extensive skin loss consistent with a diagnosis of TEN. He was intubated for complications of TEN (pneumonia) and maintained on bed rest for several weeks. In addition, he developed HO that resulted in multiple joint contractures. He was treated with aggressive range of motion by physical therapy, surgical resection of the HO followed by radiation to both elbows, right hip, and right knee. Postoperative outpatient rehabilitation enabled improved function in his mobility and activities of daily living. HO is known to occur after spinal cord and brain injuries and burns. It has not been reported to occur after TEN. Our experience with this case suggests that HO may merit inclusion into the list of complications of TEN.     

Nosocomial infection in Auckland Healthcare hospitals

AIM: To determine the prevalence of nosocomial infection in Auckland Healthcare hospitals. BACKGROUND: Nosocomial infections cause patient morbidity and prolong hospital stay. Reporting surveillance results to staff has been shown to reduce nosocomial infection rates. METHOD: Point prevalence study for all patients in Auckland, Green Lane and National Women's hospitals. Standard definitions for nosocomial infections were used. RESULTS: One hundred and ten (12%) of 932 patients had 129 nosocomial infections: 27 (20%) surgical site infections; 25 (19%) lower respiratory tract infections; 23 (18%) skin/ soft tissue infections; 19 (15%) urinary tract infections; 14 (11%) bloodstream infections; and 21 (17%) other infections. Predominant organisms were: Staphylococcus aureus (29%), Escherichia coli (21%), other gram negative bacilli (14%), Pseudomonas aeruginosa (6%), streptococci (6%) and Candida albicans (6%). The prevalence of nosocomial infection was lower in National Women's Hospital (5%) than either Green Lane or Auckland hospitals (15% and 14% respectively), p < 0.01. The prevalence of nosocomial infection was the same in medical and surgical patients, 53 of 394 (14%) and 42 of 297 (14%), respectively. The highest prevalence was in intensive care unit patients, 7 of 31 (23%). The prevalence of nosocomial infection increased with patient age, 17-50 yr (8%) vs > 50 yr (14%), p < 0.01, and duration of hospitalisation 2% for < 2 days, 6% for 2-7 days vs 22% for > 7 days, p < 0.01. Risk factors for nosocomial infection were present in many patients: 339 (36%) had intravenous catheters in place; 268 (29%) patients had undergone surgery during their current admission; 122 (13%) had urinary catheters in place; and 122 (13%) had other invasive devices in situ. CONCLUSION: Our results are comparable with hospitals of similar size overseas. This study provides a base line for future studies which will enable the monitoring of trends over time and the impact of focused infection control initiatives.     

Necrotizing soft-tissue infections

OBJECTIVES: To evaluate the causes of necrotizing soft-tissue infections (NSTls) and to determine the outcomes of patients with NSTls. DESIGN: A restrospective survey of the causes and factors associated with the outcomes. SETTING: An urban community hospital serving an indigent population. PATIENTS: A consecutive series of patients with NTSls who were treated between December 11, 1990, and December 28, 1995. INTERVENTIONS: Patients were treated with operative debridement, intravenous antibiotics, and supportive measures. MAIN OUTCOME MEASURES: Patient outcomes, causes, the extent of infection, the health status of the patients, causative organisms, and treatment delays. RESULTS: Forty-five patients with NSTls were identified. Twenty-eight cases (62%) have occurred since January 13, 1994. Parenteral drug abuse, the causative event in 25 cases (56%), accounted for 21 (75%) of the 28 cases identified since January 13, 1994. Skin flora were the primary isolates in 18 (40%) of the cases; 78% of these flora were polymicrobial. Clostridial species were isolated in 8 (18%) of the cases. The overall mortality was 27%. Survivors had less extensive infections and were more stable hemodynamically than nonsurvivors. Patients with necrosis and cellulitis greater than 250 cm2 were less likely to survive than those with less extensive infections. Logistic regression analysis identified the extents of infection, the initial blood pressure, and the initial temperature as independent predictors of outcome in this patient series. CONCLUSIONS: This is 1 of the largest reported series of patients with NSTls in which parenteral drug abuse is a prevalent causative factor. The proportion of NSTls attributable to the injection of illicit substances has increased notably in the past 2 years and has reached epidemic proportions. Survivors of NSTls had less extensive infections and were more often hemodynamically stable than nonsurvivors. Clostridial species were common in patients with NSTls related to parenteral drug abuse, underscoring the need for awareness of the potential for wound botulism in these patients.     

Acute ethanol intoxication increases the risk of infection following penetrating abdominal trauma

Acute alcohol (ETOH) intoxication as a risk factor for infection in trauma victims to our knowledge has not been previously reported. To determine if ETOH intoxication increases infection risk we examined data from 365 patients with penetrating abdominal trauma who were enrolled in a multi-center antibiotic study. Ninety-four patients sustained an injury to a hollow viscus. To separate acute from chronic ETOH effects, infections were divided into two categories: (1) trauma related; infections caused by bacterial contamination at the time of injury, while blood alcohol level (BAL) was elevated. (2) nosocomial; infections caused by bacteria acquired during hospital stay, after BAL had normalized. A BAL > or = 200 mg/dL was associated with a 2.6-fold increase in trauma-related infections. There was no association between BAL and subsequent nosocomial infection. Since infection rates for intoxicated patients were not higher after BAL had normalized, acute rather than chronic effects of ETOH appear to be responsible.     

The fluoroquinolones as treatment for infections caused by gram-positive bacteria

The fluoroquinolones have become attractive options as treatment for a broad range of infections caused by Gram-negative bacteria. However, the value of these antibiotics to patients with infections caused by Gram-positive pathogens remains controversial. Experience with quinolones as therapy for skin and skin structure infections, osteomyelitis and peritonitis in patients receiving continuous ambulatory peritoneal dialysis suggests that the concerns which have been expressed about the use of these agents against methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus epidermidis and streptococci are justified; indeed, the frequent emergence of quinolone-resistant strains of MRSA and coagulase-negative staphylococci either during or following treatment is now well documented. The fluoroquinolones should be prescribed with caution to patients with community-acquired pneumonia or whenever severe infection of pneumococcal aetiology is proven or suspected. As prophylaxis for the granulocytopenic patient, quinolones such as norfloxacin and ciprofloxacin have been shown to be effective in reducing the incidence of morbidity attributable to Gram-negative bacteria, but they have not significantly affected the incidence of infection caused by Gram-positive bacteria. In the treatment of febrile episodes in the neutropenic patient, ciprofloxacin, the quinolone investigated most extensively in this clinical setting, produced high cure rates only when it was combined with an antibiotic which was predictably active against Gram-positive organisms. We review here the role of currently-available fluoroquinolones (norfloxacin, enoxacin, pefloxacin, ofloxacin and ciprofloxacin) as treatment for these and other infections.     

Serious group A beta-hemolytic streptococcal infections complicating varicella

STUDY OBJECTIVE: To alert practicing emergency physicians to an important and possibly increasing relationship between life-threatening group A beta-hemolytic streptococcal (GABHS) infections and children recovering from varicella. DESIGN: A case series of six patients managed from January through March 1993. SETTING: A university-affiliated pediatric specialty emergency department. TYPE OF PARTICIPANTS: Six previously healthy immunocompetent children between 1 and 5 years of age seen in our ED over a nine-week period. RESULTS: Six children had onset of varicella two days to two weeks before developing a serious life-threatening GABHS infection. Children presented with clinical symptoms of invasive GABHS infection with bacteremia (one patient); streptococcal toxic shock syndrome with negative blood culture (two), pneumonia with pleural effusion and streptococcal toxic shock syndrome (one), pneumonia with pleural effusion (one), and pyomyositis of the thigh (one). Four of six patients required intensive care admissions and aggressive support of vital signs. All six survived. CONCLUSION: Emergency physicians should be aware of the association between varicella and serious GABHS infections and be prepared to recognize and aggressively manage serious complications should they occur.     

Selective breeding of rats for high and low motor activity in a swim test: toward a new animal model of depression

In three successive experiments, the immune functions of pigs persistently infected with the porcine reproductive and respiratory syndrome virus (PRRSV) have been evaluated. Non-specific immune responses were analyzed over a period of 12 weeks post-infection (PI). In addition, the capacity of PRRSV-infected pigs to develop an efficient immune response against pseudorabies virus (PRV) glycoproteins and to resist to a subsequent virulent challenge was investigated. Our results demonstrate that PRRSV produced minor effects on the immune system of pigs. The skin delayed type hypersensitivity (DTH) in response to phytohemagglutinine injection was slightly diminished one week after challenge, but was restored thereafter. However, three weeks after the infection, the total white blood cell count, and the number of CD2+, CD8+ and IgM+ cells were enhanced. The increase in numbers of CD8+ cells persisted for three consecutive weeks. Serum immunoglobulins in infected pigs also increased by week 3 PI and up to 8 weeks PI. These results show that PRRSV may have stimulating effects on the pig immune system during the phase of long-lasting infection. After immunization with PRV glycoproteins, the production of anti-PRV antibodies and skin DTH response against PRV glycoproteins were not affected. On the contrary, following a virulent PRV challenge, PRRSV-infected pigs developed a better secondary antibody response and their resistance to the infection was as effective as in control pigs. Taken together, our data do not support a systemic immunosuppressive effect of PRRSV, during the persistent phase of infection. Other mechanisms may therefore apply to explain the emergence of secondary infections in endemically infected herds.