Isolation and characterization of wide host range lytic bacteriophage AP22 infecting Acinetobacter baumannii

Abstract

Acinetobacter baumannii plays a significant role in infecting patients admitted to hospitals. Many A. baumannii infections, including ventilation-associated pneumonia, wound, and bloodstream infections, are common for intensive care and burn units. The ability of the microorganism to acquire resistance to many antibiotics, disinfectants, and dehydration assures its long-term survival in hospital settings. The application of bacteriophages is a potential tool to control A. baumannii infections. Bacteriophage AP22 lytic for A. baumannii was isolated from clinical materials and classified as a member of the Myoviridae family. The phage had an icosahedral head of 64 nm in diameter and a contractile tail of 85-90 nm in length. According to restriction analysis, AP22 had 46-kb double-stranded DNA genome. The phage AP22 exhibited rapid adsorption (> 99% adsorbed in 5 min), a large burst size (240 PFU per cell), and stability to the wide range of pH. The bacteriophage was shown to specifically infect and lyse 68% (89 of 130) genotype-varying multidrug-resistant clinical A. baumannii strains by forming clear zones. Thus, it could be used as a candidate for making up phage cocktails to control A. baumannii-associated nosocomial infections.

Characterization and Detection of Endolysin Gene from Three Acinetobacter baumannii Bacteriophages Isolated from Sewage Water

“…Bacteriophage ØABP-02 and ØABP-04 were classified into the family Myoviridae. This family was also reported in bacteriophages ABp53, ZZ1 and AP22 [16,18,19].…”

“…To date, most of A. baumannii bacteriophage isolates are DNA phages [14,15,16,18,19,22]. PFGE analysis revealed that phage DNA ØABP-01 and ØABP-04 have genome sizes of approximately 30 kb and ØABP-02 showed a larger genome size of approximately 240 kb (Fig.…”

“…ØABP-01 had a shorter latent period and displayed good lytic activity compared to other bacteriophage isolates. Previous reports of bacteriophages infecting A. baumannii showed latent periods ranging from 9 to 25 min and burst size from 22 to 409 PFU/infected cell [14][15][16][18][19][20][21][22].…”

“…Phage endolysins have been studied in a variety of pathogenic bacteria including A. baumannii for theirs antibacterial activity [11][12][13]. In the past three years, A. baumannii bacteriophages and endolysin have been isolated and characterized [14][15][16][17][18][19][20][21][22][23][24]. However, there are geographic differences in A. baumannii host strains.…”

In vitro design of a novel lytic bacteriophage cocktail with therapeutic potential against organisms causing diabetic foot infections

“…EU418428). Nevertheless, the host ranges of the Pseudomonas and Acinetobacter bacteriophages were remarkable compared with those of other species-specific bacteriophages (Merabishvili et al, 2009;Popova et al, 2012). The overall morphology, genomic characterization and hostrange results suggested that these bacteriophages are very good candidates for BT.…”