Biofilm-Related Genes: Analyses in Multi-Antibiotic Resistant Acinetobacter Baumannii Isolates From Mainland China

Abstract

BackgroundAcinetobacter baumannii is an important nosocomial pathogen which shows a high level of mortality risk. Several papers have reported biofilm formation as a well-known pathogenic mechanism in A. baumannii infections and exceptional antibiotic resistance. The study aims to explore the potential relationships between biofilm-related genes and antimicrobial resistance.Material/MethodsSamples from 122 patients with lower respiratory tract infections of A. baumannii were collected at Fujian Longyan First Hospital from January 2013 to September 2014. A. baumannii was isolated from sputum specimens. Biofilm-related genes including abaI, csuE, ompA, and bla-PER1 were analyzed by PCR. The minimum inhibitory concentration method was used to determine the sensitivity of each strain to antibiotics.ResultsThe clinical manifestations of A. baumannii-induced lower respiratory tract infections lacked specificity. Infected patients were most commonly admitted to intensive care units (54.9%) and frequently had chronic obstructive pulmonary disease (27.0%). The detection rates of abaI and csuE were both 59.8%, and those of ompA and bla-PER1 were 100% and 0%, respectively. After genetic testing, antimicrobial resistance to amikacin, ampicillin/sulbactam, and 14 other types of antimicrobials was higher in abaI- and csuE-positive strains than in abaI- and csuE-negative strains (P<0.05).ConclusionsThe findings of our study suggest that abaI- and csuE-positive Acinetobacter baumannii strains are associated with a higher incidence of antibiotic resistance in 14 types of antimicrobials.

Quorum Sensing as a Target for Controlling Surface Associated Motility and Biofilm Formation in Acinetobacter baumannii ATCC® 17978TM

“…Biofilm formation has been found to be correlated with MDR among clinical isolates ( Babapour et al, 2016 ; Yang et al, 2019 ; Zeighami et al, 2019 ). Higher incidence of antibiotic resistance has also been associated with the presence of abaI and csuE genes in clinical A. baumannii strains ( Liu et al, 2016 ). On the contrary, another study could not find any relationship between isolation site, multidrug resistance, pulsed-field type and biofilm production among A. baumannii clinical and environmental strains isolated from a hospital ( de Campos et al, 2016 ).…”

Association of virulence gene expression with colistin-resistance in Acinetobacter baumannii: analysis of genotype, antimicrobial susceptibility, and biofilm formation

“…While, some studies have associated the presence of specific virulence genes with an increase in the pathogenic potential of clinical isolates [ 47 , 48 ], the association between the virulence gene expression of A. baumannii and the susceptibility to specific antimicrobial agents has not been assessed. In fact, despite several reports regarding the increase in the prevalence of Cst-resistance among MDR-AB isolates worldwide [ 8 – 14 , 45 ], few studies have focused on the possible link between Cst R , and the expression of virulence genes that can potentially affect therapy outcome. We have used a murine burn infection model to demonstrate that mRNA levels of virulence genes dnaK, blsA, recA, and lpsB vary in Cst-R-AB isolates depending on whether they are cultured in vitro or in vivo.…”

“…Reports from various parts of the world have indicated a worrisome growing trend of isolating multi-, extensive- and pan-drug resistant (MDR, XDR, and PDR) strains of A. baumannii, some of which are even resistant to colistin, a last resort drug [ 8 – 13 ]. Whether the expression of virulence determinants, such as genes involved in biofilm formation, play an important role in the high rate of treatment failure among wound infections caused by highly resistant A. baumannii isolates remains to be explored [ 14 ].…”

Antibiofilm and Antivirulence Efficacies of Flavonoids and Curcumin Against Acinetobacter baumannii

“…Acinetobacter baumannii has been documented to be the most successful indigenous pathogen in healthcare institutions (Howard et al, 2012; Pakharukova et al, 2018). A. baumannii is an opportunistic Gram-negative bacillus that is responsible for a variety of nosocomial infections with high morbidity and mortality rates, these include, pneumonia, wound infections, bloodstream infections, urinary tract infections, and secondary meningitis (Howard et al, 2012; Liu et al, 2016). Furthermore, in intensive care neonatal and burns units, A. baumannii is one of the most commonly encountered pathogens (Seifert et al, 1994) (a claim shared with Pseudomonas aeruginosa and Staphylococcus aureus ) (Paling et al, 2017a, b).…”