<p>Detection and Control of Biofilm Formation by <em>Staphylococcus aureus</em> from Febrile Neutropenic Patient</p>

Abstract

Introduction Febrile neutropenia (FN) is the evolution of fever in a patient with neutropenia over 38.0°C. Neutropenia is diagnosed when absolute neutrophil count (ANC) <1500 cells/µL. FN represents a common complication of cancer treatment. Hence, it is featured to be a major cause of morbidity and mortality in cancer patients. Staphylococcus aureus is one of the most important microorganisms isolated from the blood of febrile neutropenic patients. Infections caused by S. aureus range from mild to life-threatening diseases. Biofilm production by S. aureus is one of the most significant virulence factors of the bacterium as it prevents the penetration of antibiotics. Recently, it has been shown that S. aureus carries the ica operon responsible for biofilm production. The aim of the work is to determine a genotypic characterization that includes not only the detection of icaA and icaD genes in S. aureus but also the determination of their relation to clinical and microbiological features. Empiric antibacterial treatment was recommended for cancer patients receiving chemotherapy. Materials and Methods The relation between the presence of icaA and icaD and biofilm production was determined in a collection of 66 S. aureus samples from febrile neutropenic patients. Biofilm-forming ability was tested on Congo Red agar plates. Also, the effect of the most sensitive antibiotics on the bacterial cells was determined by an electron microscope. Results Of the bacterial samples, 48 were biofilm-productive and 18 were non-biofilm productive. For the biofilm productive bacteria, 37.5% were positive for icaA , 22.9% were positive for icaD and 10.4% were positive for both. Linezolid was the most effective antibiotic and it is highly recommended for the treatment of febrile neutropenia caused by biofilm-productive S. aureus . Severe changes were found on the bacterial cell after being treated with Linezolid. The icaA and icaD genes were present in only 50% of biofilm-productive bacteria. Conclusion The ica operon is present in only 50% of biofilm-productive S. aureus and Linezolid is the best antibiotic against these bacteria.

Phenotypic and Genotypic Detection of Biofilm-Forming Staphylococcus aureus from Different Food Sources in Bangladesh

“…The present study revealed that the occurrence rates of biofilm-producing genes are much lower than the results observed in the CRA and CVMP tests. Similar findings were reported by previous studies [ 44 , 45 ], however, the high and similar prevalence rates of biofilm-producing S. aureus observed in the qualitative, quantitative, and molecular assays were recorded in previous studies [ 10 , 46 , 47 ]. This discrepancy could be explained by the different factors that are associated with biofilm formation in the S. aureus isolates.…”

Correlation Between Biofilm-Formation and the Antibiotic Resistant Phenotype in Staphylococcus aureus Isolates: A Laboratory-Based Study in Hungary and a Review of the Literature

“…Among the tested strains, 37.5% were positive for icaA, and 22.9% were positive for icaD; however, only 50% of biofilm-producers carried either the icaA or icaD genes. 64 Similarly, no correlation among methicillin-resistance and biofilm-production was seen in the reports of Knobloch et al (including n=128 icapositive isolates, with utilizing CRA plates and the microtiter plate method) 65 and Mathur et al (where n=152 Staphylococcus spp. were tested using the microtiter plate method).…”

Level of biofilm production by Staphylococcus aureus isolates is critical for resistance against most but not all antimicrobial drugs

“…12 As biofilm is one of the major causes of amplifying antibiotic resistance, hence biofilm detection helps in investigating the severity of infection by S. aureus. 13 This study focused on general relationship between biofilm production and multidrug resistance in S. aureus isolates, and its effect on recommended antimicrobials. Penicillin, in general, was ineffective against all isolates.…”