Bacterial floras and biofilms of malignant wounds associated with breast cancers

Abstract

The risk of infections and the appearance of symptoms (e.g., odors) represent the main troubles resulting from malignant wounds. The aim of this study was to characterize the balance of bacterial floras and the relationships between biofilms and bacteria and the emergence of symptoms. Experimental research was carried out for 42 days on malignant wounds associated with breast cancer. Investigations of bacterial floras (aerobes, aero-anaerobes, and anaerobes), detection of the presence of biofilms by microscopic epifluorescence, and clinical assessment were performed. We characterized biofilms in 32 malignant wounds associated with breast cancer and bacterial floras in 25 such wounds. A mixed group of floras, composed of 54 different bacterial types, was identified, with an average number per patient of 3.6 aerobic species and 1.7 anaerobic species; the presence of strict anaerobic bacterial strains was evidenced in 70% of the wounds; biofilm was observed in 35% of the cases. Odor was a reliable indicator of colonization by anaerobes, even when this symptom was not directly linked to any of the identified anaerobic bacteria. Bacteria are more likely to be present during myelosuppression and significantly increase the emergence of odors and pain when present at amounts of >10(5) · g(-1). The presence of biofilms was not associated with clinical signs or with precise types of bacteria. No infections occurred during the 42-day evaluation period. This study provides a dynamic description of the bacterial floras of tumoral wounds. The study results highlight the absolute need for new therapeutic options that are effective for use on circulating bacteria as well as on bacteria organized in biofilm.

Fig 1

Relative frequencies of the numbers of different aerobic () and anaerobic (□) species per patient as observed on day 21.

Fig 2

Impact of the presence of strict anaerobes (A) and the numbers of bacterial species (B, C) on various symptoms. (A) Impact of the presence of strict anaerobic species on odors (no odor, ; odor from weak to strong, □). (B) Impact of bacterial species number on odors (no odor, ; odor from weak to strong, □). (C) Impact of bacterial species number on exudates (no/weak exudate, ; moderate/strong exudate, □).

Fig 3

Impact of bacterial load on symptoms. (A) Impact of bacterial load on odor intensity (no odor, □; weak odor, ; moderate odor, ; strong odor, ■) (P = 0.56). (B) Impact of bacterial load on exudates (no exudate, □; weak exudate, ; moderate exudate, ; strong exudate, ■) (P = 0.07). (C) Impact of bacterial load on pain (no pain, □; weak pain, ; moderate pain, ▩; strong pain, ; intense pain, ■) (P = 0.04).

Fig 4

Biofilm identification on tumoral wounds using epifluorescence microscopy. Samples were stained with lectins coupled to fluorochromes and DAPI. Samples of patients 1 and 2, lectins Bandeiraea simplicifolia-tetramethylrhodamine isothiocyanate (TRITC) and Lycopersicon esculentum-fluorescein isothiocyanate (FITC); samples of patients 6 and 7, lectins Arachis hypogaea-TRITC and Lycopersicon esculentum-FITC.