Can Methicillin-resistant Staphylococcus aureus Silently Travel From the Gut to the Wound and Cause Postoperative Infection? Modeling the "Trojan Horse Hypothesis".

OBJECTIVE: To determine whether intestinal colonization with methicillin-resistant Staphylococcus aureus (MRSA) can be the source of surgical site infections (SSIs). BACKGROUND: We hypothesized that gut-derived MRSA may cause SSIs via mechanisms in which circulating immune cells scavenge MRSA from the gut, home to surgical wounds, and cause infection (Trojan Horse Hypothesis). METHODS: MRSA gut colonization was achieved by disrupting the microbiota with antibiotics, imposing a period of starvation and introducing MRSA via gavage. Next, mice were subjected to a surgical injury (30% hepatectomy) and rectus muscle injury and ischemia before skin closure. All wounds were cultured before skin closure. To control for postoperative wound contamination, reiterative experiments were performed in mice in which the closed wound was painted with live MRSA for 2 consecutive postoperative days. To rule out extracellular bacteremia as a cause of wound infection, MRSA was injected intravenously in mice subjected to rectus muscle ischemia and injury. RESULTS: All wound cultures were negative before skin closure, ruling out intraoperative contamination. Out of 40 mice, 4 (10%) developed visible abscesses. Nine mice (22.5%) had MRSA positive cultures of the rectus muscle without visible abscesses. No SSIs were observed in mice injected intravenously with MRSA. Wounds painted with MRSA after closure did not develop infections. Circulating neutrophils from mice captured by flow cytometry demonstrated MRSA in their cytoplasm. CONCLUSIONS: Immune cells as Trojan horses carrying gut-derived MRSA may be a plausible mechanism of SSIs in the absence of direct contamination.

Pelvic and abdominal-wall actinomycotic infection by uterus gateway without genital lesions.

We hereby aim to account on a case of actinomycotic infection occurred in a female patient with an intrauterine contraceptive device (IUCD). The infection occurred as a pseudo-tumour which raised differential diagnosis issues with a malignant tumour. The diagnosis has been eventually established following the pathologic examination of paraffin-embedded tissues. Although the infection's gateway was the uterus, the subsequent invasion of the parietal, urinary bladder and lateral rectal walls did not seem to affect the fallopian tubes or the ovaries.

[Leech-borne infection on a TRAM flap: a case report]. / Complication infectieuse d'un lambeau de TRAM liée aux sangsues: à propos d'un cas.

Leeches are used worldwide to treat venous congestion of flaps. Aeromonas hydrophila infections are recognized complications of leech use. We report a new case of delayed leech-borne infection in mammary reconstruction by a Transverse Rectus Abdominis Myocutaneous flap (TRAM), which caused the flap loss. The use of prophylactic antibiotics is a way to prevent A.hydrophila infection (third generation cephalosporin, ciprofloxacin). This antibioprophylaxy must be followed until wound closure of the venous congested tissue.

[Urachal actinomycosis: apropos of a case]. / Actinomicosis uracal: a propósito de un caso.

The report a new case of infected urachal cyst. The embryologic origin of the urachus, its anomalies, clinical features, diagnosis and treatment are discussed with the case of a 51 years old man who presented an hypogastric mass with the diagnosis of urachal actinomycosis.