No abstract

We present Stenotrophomonas maltophilia infections in 317 hospitalized patients in a large health network over a 3-year period. The majority of patients were elderly. Most infections were polymicrobial: respiratory 95.2%, wound 91%, urinary 80.8% and blood 64.3%. Younger patients were small in number and were more common in those with otitis externa, infections from injection drug use and those with line infections. Most deaths were in patients with terminal conditions and polymicrobial infections and mortality could not be directly attributed to Stenotrophomonas maltophilia. None of the sputum, bronchial, urinary or wound culture positive patients had positive blood cultures. Only blood (14/317) or ear (7/317) culture positive patients had significant numbers of younger individuals with only 3 out of 14 over age 50 in blood culture positive patients and 1/7 in those with otitis externa. Those with bacteremia included patients with injection drug use, chronic pain syndromes and vascular catheter infections. 94% of urinary infections, 91.7% wound infections and 85.8% respiratory isolates were in those above age 50. Overwhelming majority of urinary infections were in males with drainage devices present in 75%. Recurrent infections were uncommon. Respiratory specimens were frequently associated with tracheostomies and endotracheal tubes. Most wound infections were in chronic lower extremity ulcers. Prior carbapenem use was not significant in this study. Isolates from all sites were over 98% susceptible to Trimethoprim/sulphamethoxazole. Limitations: The study group only had 1 organ transplant and 2 cystic fibrosis patients and no burn wound infections.

Infections are common in IV drug users (IVDU). Heroin was by far the most common drug abused in our series of 80 patients. The spectrum of infections in our patients with ages ranging from 20-63, varied from mild skin infections to life threatening and fatal conditions such as septic shock, necrotizing fasciitis, spinal cord infarction and endocarditis with cerebral septic emboli. Our studies showed that bacterial infections in IV drug users originate from three different sources: 1. Skin (contaminated hands) 2. Oral microbiota 3. Environmental sources including water, soil and plants. The most common skin bacteria isolated were methicillin susceptible and methicillin resistant Staphylococcus aureus (MSSA and MRSA). In our study Streptococcus anginosus group was the most common oral bacteria in IVDU with Streptococcus intermedius predominating, followed by group A Streptococcus, Prevotella spp., Eikenella corrodens, Haemophilus parainfluenzae and group C Streptococcus. A variety of environmental bacteria were isolated, but the total number of patients in this group was smaller. Bacteria originating from water, soil or plants present were: Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Delftia acidovorans, Commamonas sp., Chryseobacterium spp., Klebsiella spp., Serratia marcesens, Burkholderia cepacia, Pseudomonas fluorescence and Acinetobacter. Twenty four out of 48 (50%) Staphylococcus aureusinfected patients were bacteremic, followed by 6/10 (60%) group A Streptococcus infected cases. Life threatening infections were more common with those infected with Staphylococcus aureus or Pseudomonas aeruginosa. Few had Candida sp., likely of oral origin. Hepatitis C was less common (2/37) 5.4% in the group with oral bacteria and more frequent in MSSA/MRSA patients (13/47) 27.7%. There was 1 coinfection with human immunodeficiency virus each in oral and skin bacteria associated groups. The bacteria isolated provided a clue to the source of infections and habits of the IV drug users.

Bursae are fluid filled structures between mobile parts of the musculoskeletal system to reduce friction by lubrication. Repeated trauma to bursae results in bursitis which are usually aseptic initially, which may be followed by infection. Many cases are related to occupational or recreational activities. We present an analysis of cases of Staphylococcus aureus septic bursitis admitted to 10 hospitals over a 3-year period. The olecranon bursa was the most common site involved 42/65 (64.6%) followed by prepatellar bursa 17/65 (26.1%). The mean age was 61.2 years. Fifty five out of Sixty-five (84.6%) were male. The majority were caused by methicillin susceptible Staphylococcus aureus 52/65 (80%). The occupational history was missing for most patients. The occupations reported in few of the patient charts were floor worker, construction worker and roofer. Sixty one out of sixty-five (92.4%) of cases involved the elbow and knee. Avoidance of activities that result in repeated friction or trauma to elbows and knees would prevent majority of cases of septic bursitis.

In our study, septic arthritis due to Staphylococcus aureus and Streptococcal species was more common in the elderly. This contrasts with Lyme arthritis which has a higher incidence in younger patients. The majority of joint infections were in the elderly, with a median age of 65 (range 14-95) for Staphylococcus aureus and 70 for Streptococcal species. The age range of Methicillin-resistant Staphylococcus aureus (MRSA) septic arthritis was 27-95 (median 72) with 39/53 (73.6%) above age 60. The age range of Streptococcal arthritis patients was 36-86 (median 70). There were more males with septic arthritis for both Staphylococcus aureus (86/134) 64% and streptococci (12/22) 55%. The most frequently involved joint was the knee, 49.3% for S. aureus followed by hip (23.9%), elbow (14.3%), shoulder (14%), wrist (1.5%), ankle (0.75%) and sternoclavicular (0.75%). The knee was affected in 81% of Streptococcal infections, with the rest equally divided between the hip, elbow, acromioclavicular and ankle joints. The history of prior joint replacement in patients with septic arthritis was 21/28 (80%) for MRSA, 36/102 (35.3%) for methicillin-susceptible Staphylococcus aureus (MSSA) and 9/21 (43%) for streptococcal arthritis suggestive of healthcare-associated infections. Our results suggest a need for improvements to prevent the entry of pathogens into the surgical site during and after surgery.