Epidemiology and antimicrobial susceptibilities of wound isolates of obligate anaerobes from combat casualties

Abstract

Data from recent conflicts related to war wounds and obligate anaerobes are limited. We define the epidemiology and antimicrobial susceptibility of obligate anaerobes from Iraq and Afghanistan casualties (6/2009–12/2013), as well as their association with clinical outcomes. Susceptibility against eleven antibiotics (7 classes) was tested. Overall, 59 patients had 119 obligate anaerobes identified (83 were first isolates). Obligate anaerobes were isolated 7–13 days post-injury, primarily from lower extremity wounds (43%), and were largely Bacteroides spp. (42%) and Clostridium spp. (19%). Patients with pelvic wounds were more likely to have Bacteroides spp. and concomitant resistant gram-negative aerobes. Seventy-three percent of isolates were resistant to ≥1 antimicrobials. Bacteroides spp. demonstrated the most resistance (16% of first isolates). Patients with resistant isolates had similar outcomes to those with susceptible strains. Serial recovery of isolates occurred in 15% of patients and was significantly associated with isolation of Bacteroides spp., along with resistant gram-negative aerobes.

Microbiology of combat-related extremity wounds: Trauma Infectious Disease Outcomes Study

“…collected from wound cultures from 59 combat casualties, 85% of isolates were recovered from infected wounds. Although 6.8% of patients with anaerobe recovery died, the pathogenic role of anaerobes is uncertain and their occurrence may be a marker of disease severity (White et al, 2016). Candida spp.…”

Antibiotic efficacy in the complex infection environment

“…Oxygen penetration is also often severely hampered in wound infections and abscesses (31, 32). Indeed, obligate anaerobes are frequently isolated from the CF lung as well as from polymicrobial wound infections, implying that anoxic microenvironments exist within these infection sites (30, 33). Within the heterogeneous infection environment, facultative anaerobes such as S. aureus, E. coli or Streptococcus pneumoniae can colonize both aerobic and anaerobic niches to cause disease, and life within these niches requires specific metabolic adaptation.…”

First isolation of Clostridium indolis in a patient with chronic osteitis: a case report and literature review of human infections related to Clostridium saccharolyticum group species

“…Three cases of C. celerecrescens infections were also described including an osteomyelitis, an abscess secondary to an open fracture and a post traumatic wound infection [7,8,17] (see table 2 Clostridium sp. susceptible to moxifloxacin, from 69% to 79% [18,19]. This data suggests that, in our case, the resistance of the strain to quinolones was probably acquired under antibiotic pressure.…”