Investigation of biofilm production and its association with genetic and phenotypic characteristics of OM (osteomyelitis) and non-OM orthopedic Staphylococcus aureus

Abstract

Background: Staphylococcus aureus is a primary pathogen of orthopedic infections. By mediating antimicrobial resistance, S. aureus biofilm plays an important role in the recalcitrance of orthopedic infections, especially for the intractable osteomyelitis (OM). This study investigated the relationship between biofilm production and various genetic or phenotypic characteristics among orthopedic S. aureus strains. Methods: A total of 137 orthopedic S. aureus isolates were enrolled and divided into OM and non-OM groups. Biofilm production was evaluated using the crystal violet assay. Genetic and phenotypic characteristics including MRSA identification, MLST and spa typing, carriage of virulence genes, drug resistance, and patients' inflammatory responses indicators were characterized. The relationship between biofilm production and above-mentioned features was respectively analyzed among all isolates and compared between OM and non-OM isolates. Results: Biofilm production presented no significant difference between OM (including 9 MRSA isolates) and non-OM (including 21 MRSA isolates) strains. We found that ST88, t377 and ST630-MSSA-t377 strains produced very strong biofilms, while MLST types of ST15, ST25, ST398, ST5, ST59 and spa types of t002, t2325, t437 tended to produce weaker biofilms. Strains with the following profiles produced stronger biofilms: fib(+)-hlgv(+)-lukED(+)-sei(-)-sem(-)seo(-) for all isolates, sei(-)-sem(-)-seo(-) for OM isolates, and cna (+)-fib (+)-hlgv (+)-lukED (+)-seb(-)-sed(-) for non-OM isolates. In addition, not any single drug resistance was found to be related to biofilm production. We also observed that, among OM patients, strains with stronger biofilms caused weaker inflammatory responses. Conclusion: Some genetic or phenotypic characteristics of orthopedic strains were associated with biofilm production, and this association could be different among OM and non-OM strains. The results are of great significance for better understanding, evaluating and managing different kinds of biofilm-associated orthopedic infections, and provide potential targets for biofilm clearance.

Promising Antibiofilm Agents: Recent Breakthrough against Biofilm Producing Methicillin-Resistant Staphylococcus aureus

“…In this study, there was no significant correlation between the biofilm production and any kind of toxin genes, suggesting that the carriage of toxin genes may be an unreliable marker to be correlated with biofilm production. In contrast with our results, a recent study conducted in China indicated that virulent strains could be more likely to be strong biofilm producers [ 27 ].…”

The Prevalence of Staphylococcus aureus and the Occurrence of MRSA CC398 in Monkey Feces in a Zoo Park in Eastern China

“…The spa type t189 was reported as one of the predominant genotypes of S. aureus from a non-human primate, which was detected in macaque, chimpanzee, and lemur [ 16 , 18 , 26 , 28 ], while spa type t377 has not been reported in wildlife species until now [ 15 ]. MSSA t377 was reported as a predominant S. aureus strain in hospitals, sporadically causing human clinical infections in China, which was also confirmed with a relatively high biofilm formation ability for its persistence and transmission in the environment [ 29 ]. Notably, MLST analysis showed that both of two MRSA t034 isolates belonged to ST398, which was not reported in any non-human primates before and was only detected from Norway rats and wild boars [ 15 ].…”

Epidemiological and Clinical Evidence for the Role of Toxins in S. aureus Human Disease

“…LukED has been specifically associated with diabetic foot infection, where one particular study found the lukED locus in every MRSA isolate from a patient infected with a diabetic foot ulcer [ 71 ]. LukED has also been associated with the carriage of other virulence factors in S. aureus strains, including biofilm production in individuals with osteomyelitis [ 72 ].…”