Kerry O. Cleveland

Risk factors for carriage of drug-resistant Streptococcus pneumoniae among children in Memphis, Tennessee

OBJECTIVES To determine risk factors for carriage of drug-resistant Streptococcus pneumoniae to understand better the factors promoting spread of these isolates. STUDY DESIGN We obtained medical and demographic information and nasopharyngeal swab specimens from 216 children less than 6 years old with upper respiratory tract infections, seeking medical care at five Memphis, Tenn, study sites. We evaluated risk factors for carriage of penicillin-nonsusceptible S. pneumoniae (NSSP) among 100 children with S. pneumoniae isolates. Patterns of antimicrobial prescription were recorded for enrolled children. RESULTS Independent risk factors for carriage of NSSP included an increased number of antimicrobial treatment courses during the previous 3 months and white race. Day care attendance approached statistical significance (p = 0.07). Most children with upper respiratory tract infection received a prescription for antimicrobial drugs. These prescriptions were more common for white children than for black children. CONCLUSIONS Increased use of antimicrobial drugs enhances the risk of carriage of NSSP. This may contribute to the higher risk among white children of NSSP infection; however, after control for antimicrobial use, white children were still at an increased risk of infection with NSSP, possibly through greater exposure to resistant strains.

Blastomycosis in immunocompromised patients.

Among the endemic mycoses, blastomycosis has been least often associated with disorders of immune function, but the data presented herein suggest that blastomycosis may occur more commonly in immunocompromised patients than was previously recognized. We have observed a marked increased in the number of immunocompromised patients with blastomycosis over the last 15 years, increasing from about 3% of patients seen between 1956 and 1977 to almost 24% patients seen between 1978 and 1991. The disease appears to be much more aggressive in immunocompromised than in normal hosts. Almost 30% of the patients in our series died secondary to blastomycosis, with most deaths occurring within 5 weeks following the diagnosis. Furthermore, almost one third of those patients who died of other causes had evidence of persistent blastomycosis at death. Multiple organ and central nervous system involvement were relatively common in this series. For these reasons, early and aggressive therapy with amphotericin B is indicated for most immunocompromised patients with blastomycosis. Oral therapy with an azole compound should probably be reserved for patients who have responded to a primary course of amphotericin B but who require additional or long-term suppressive therapy. Until more data are available, the newer azoles should be used with caution as primary therapy in immunocompromised patients with blastomycosis, and considered only in patients with limited disease and a stable underlying condition. Caring for the immunocompromised patient poses many diagnostic and therapeutic challenges to the clinician, and among those patients who have been exposed to areas endemic for blastomycosis, B. dermatitidis must be regarded as a potentially important opportunistic pathogen.

Telavancin for the treatment of methicillin-resistant Staphylococcus aureus osteomyelitis

Sir, With a rapid increase in invasive infections caused by methicillinresistant Staphylococcus aureus (MRSA), there is a demand for antimicrobials with enhanced activity against MRSA. The concentration-dependent, bactericidal lipoglycopeptide telavancin was approved in 2009 for treatment of complicated skin and skin-structure infections due to susceptible organisms. The emergence of glycopeptide resistance and clinical failures of vancomycin therapy in invasive MRSA infections, including osteomyelitis, has led to the unlabelled use of alternatives to vancomycin for treatment of these infections. We report four patients with MRSA osteomyelitis who failed standard vancomycin therapy and were successfully retreated with telavancin and surgical intervention. A patient was admitted with inability to ambulate for 1 day. This was preceded by a 4 day history of progressive leg weakness and a 2 month history of lower back pain. There also was a history of multiple carbuncles of the face, neck and buttocks, but no antimicrobial therapy had been administered for these. No fever was present. White blood cell (WBC) count, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were elevated. Magnetic resonance imaging (MRI) revealed T4–7 vertebral osteomyelitis as well as T5–6 discitis with an anterior epidural phlegmon and stenosis with spinal cord compression. T5–6 laminectomy with drainage of the epidural abscess and decompression of the spinal cord was performed. Treatment with cefepime 2 g intravenously (iv) every 8 h and vancomycin 18 mg/kg iv every 12 h was begun. Blood cultures were negative, but MRSA was identified from culture of the abscess 72 h later. Vancomycin MIC was 2 mg/L, linezolid MIC was 2 mg/L and daptomycin MIC was 1 mg/L. Therapy was changed to daptomycin 6 mg/kg iv daily. After the back pain and WBC were noted to have improved, the patient was discharged to a physical rehabilitation centre to complete a planned 8 week course of daptomycin. Two weeks later, because of progressive leg weakness, fever and re-elevation of WBC, ESR and CRP values, the patient was readmitted. MRI showed recurrent epidural abscess at T5–6. T4–6 laminectomy was performed with drainage of the recurrent abscess and cord decompression. Culture of the abscess again grew MRSA (vancomycin MIC 2 mg/L, daptomycin MIC 1 mg/L and telavancin MIC 0.38 mg/L). Treatment was changed to telavancin 10 mg/kg iv daily. While receiving 10 weeks of telavancin therapy, there was resolution of fever and leucocytosis and normalization of ESR and CRP values. Gradual recovery of leg strength and ability to ambulate was noted. There was no evidence of recurrent infection 4 months after completion of telavancin. A patient with the sudden onset of leg weakness and urinary incontinence was transferred from another hospital after a lengthy hospitalization with MRSA bacteraemia (vancomycin MIC 1 mg/L, linezolid MIC 2 mg/L and daptomycin MIC ≤0.5 mg/L) from cellulitis complicated by sepsis, respiratory failure with pneumonia, renal dysfunction and hepatic encephalopathy. Despite sequential treatment with adequate doses of vancomycin (14 days), linezolid (7 days) and daptomycin (14 days), the MRSA bacteraemia persisted with unchanged MIC values. Fever was absent. WBC, ESR and CRP values were elevated. Transthoracic echocardiography and transoesophageal echocardiography (TOE) did not reveal valvular vegetations. MRI showed an epidural abscess extending from T6 to L2, L1 vertebral osteomyelitis and a left psoas abscess. Telavancin 10 mg/kg iv daily was begun. T6–7 decompressive laminectomy was performed and the abscess was evacuated. Cultures of the blood and abscess grew MRSA with unchanged MIC values of vancomycin, linezolid and daptomycin. Telavancin MIC was 0.25 mg/L. Telavancin was administered for 8 weeks with improvement in leg weakness and normalization of WBC, ESR and CRP values. There was no evidence of recurrence 7 months after completion of telavancin. A patient presented with a 1 week history of right hip pain after a fall. Fever and leucocytosis were present. There was a remote history of a gunshot wound to the right hip. CT revealed a 2 cm mass in the left upper lung and a large right hip effusion. MRI was consistent with right hip septic arthritis and osteomyelitis of the right acetabulum, femoral head, femoral neck and lesser trochanter. Blood cultures grew MRSA (vancomycin MIC 1 mg/L, linezolid MIC 1 mg/L and daptomycin MIC ≤0.5 mg/L). Ceftriaxone 2 g iv daily and vancomycin 13 mg/kg iv every 12 h were begun and continued for 5 days. Research letters

Vancomycin therapy and the progression of methicillin-resistant Staphylococcus aureus vertebral osteomyelitis.

Vancomycin therapy is the standard treatment for methicillin-resistant Staphylococcus aureus (MRSA), the most common cause of vertebral osteomyelitis, an increasingly frequent complication of nosocomial bacteremia. We report five recent cases suggesting that, while giving the appearance of success by conventional clinical and laboratory criteria (eg, resolution of fever and leukocytosis), vancomycin monotherapy may in fact be insufficient to prevent or reverse the progression of hematogenous MSRA vertebral osteomyelitis. A review of the literature and possible therapeutic alternatives are also discussed.

Trichosporon mucoides fungemia in a liver transplant recipient: case report and review

Abstract: Four months after receiving an orthotopic liver transplant, a 51‐year‐old man was admitted for progressive liver failure and severe hepatocellular necrosis thought to be due to tacrolimus. During his hospitalization he experienced bloodstream infections including fungemia due to Trichosporon mucoides and prolonged undulating fever despite antifungal and antibacterial treatment. He underwent removal of the allograft and implantation of another liver. Fever continued postoperatively until therapy with posaconazole was initiated. Initiation of posaconazole led to clinical improvement until the patients demise from bacteremic vancomycin‐resistant enterococcal peritonitis. Trichosporonosis appears to be an emerging fungal infection among immunocompromised individuals (including both hematological and solid organ transplant recipients). T. mucoides is a rare cause of systemic infection. When it occurs, trichosporonosis usually is associated with hematological malignancies and, to the best of our knowledge, has not been previously reported in a liver transplant recipient. The optimal treatment is not well defined. We report here the first case using posaconazole for treatment of trichosporonosis in a liver transplant recipient caused by T. mucoides.

Pathological Fracture in Acute Osteomyelitis of Long Bones Secondary to Community-Acquired Methicillin-Resistant Staphylococcus aureus: Two Cases and Review of the Literature

Pathologic fracture is a rare complication of acute bacterial osteomyelitis in adults. Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) has been increasingly reported in skin and soft tissue and systemic infections in children and adults, including many cases of osteomyelitis. We recently treated two adult patients with acute osteomyelitis of long bones secondary to CA-MRSA complicated by a pathologic fracture. In both patients, the primary source of dissemination to the bone was a skin and soft tissue infection. We speculate that virulence factors specific for CA-MRSA currently circulating in the United States may predispose to a complicated course of acute osteomyelitis.

Community-Acquired Methicillin-Resistant Staphylococcus aureus and Lemierre Syndrome

Lemierre syndrome is usually caused by Fusobacterium necrophorum, but we recently encountered a case due to methicillin-resistant Staphylococcus aureus and complicated by sigmoid sinus thrombosis and cranial neuropathies. Therapy may be made more difficult by unusual organisms and also create the need for therapy that penetrates into the central nervous system.

A case of disseminated histoplasmosis following autologous stem cell transplantation for Hodgkin's lymphoma: an initial misdiagnosis with a false-positive serum galactomannan assay.

Abstract: Systemic histoplasmosis is uncommonly reported in patients who have undergone bone marrow or solid organ transplantation. Diagnosis of systemic histoplasmosis in recipients of transplants may be hampered by lack of consideration of this infection in the differential diagnosis and may be confounded by conflicting information from other testing performed to evaluate for opportunistic infections in this population. We report successful treatment of a case of disseminated histoplasmosis in a patient with Hodgkins lymphoma who had undergone autologous stem cell transplantation. The diagnosis was delayed by the finding of a positive serum galactomannan assay.

Successful therapy of treatment-emergent, non-clonal daptomycin-non-susceptible Enterococcus faecium infections

with reduced susceptibility (,23 mm inhibition zone diameter or MIC .1 mg/L) to any of the carbapenems (ertapenem, imipenem or meropenem) will be tested for the carbapenemase phenotype by the combined disc method (with EDTA or boronic acid). All strains with a positive phenotype will be sent to a reference laboratory for molecular testing. Hence, implementation of the new CLSI criteria would not simplify the laboratory testing and reporting procedure in our locality. Although susceptibility of Proteus spp., Providencia spp. and M. morganii to imipenem is recognized to be lowered and could be caused by mechanisms other than carbapenemase production, the extent of the effect that applying the new interpretive criteria would have on clinical isolates has not been previously described. Here, we showed that susceptibility categorization for this group of organisms could change by up to 61.4%. Laboratories that choose to implement the new criteria should clearly inform infection control personnel so that there will not be any misunderstanding of outbreak occurrence. In conclusion, this study showed that applying the new CLSI criteria to interpret carbapenem susceptibility in Enterobacteriaceae would drastically change the susceptibility rates for some isolate groups. Furthermore, the FDA-approved breakpoints have not been changed. This explains why many clinical laboratories continue to use the old breakpoints and perform phenotypic testing for carbapenemase production. Our findings emphasize the need to obtain more clinical outcome data.

Bordetella bronchiseptica bacteremia in a patient with AIDS.

Bordetella bronchiseptica bacteremia is often associated with various infection in animals. The majority of B bronchiseptica infections reported in humans are cases of pneumonia. Very few cases have been reported in patients with a history of acquired immune deficiency syndrome (AIDS). The patient described herein, who had a history of AIDS, was likely infected with B bronchiseptica as a result of his hemodialysis catheter. The patient was successfully treated with antibiotics without the removal of the catheter.