Molecular detection of hypervirulent Klebsiella pneumoniae (hvKp) in Egyptian poultry

Abstract

The emergence of hypervirulent Klebsiella pneumoniae (hvKp) in poultry represents a significant and growing threat to both public health and the poultry industry. However, epidemiological data on hvKp in Egyptian poultry remain limited. In this One Health–focused study, 150 cloacal swabs from broiler chickens, 30 hand swabs from workers in direct contact with the birds, and 20 drinking water samples were collected from six poultry farms in Giza Governorate, Egypt. All samples were processed using standard microbiological methods, and the presence of K. pneumoniae was confirmed through molecular detection of the gyrA gene and the 16–23 S ITS region. Hypervirulent K. pneumoniae strains were characterized by multiplex PCR targeting key virulence determinants (rmpA, rmpA2, iucA, iroB, and peg-344) and capsular serotypes (K1 and K2). Additional virulence-associated markers (entB, kfu, and mrkD) were also evaluated to assess their pathogenic potential. K. pneumoniae was identified in 13.3% (20/150) of chicken samples, while exhibiting a prevalence of 10% in both workers (3/30) and water (2/20) samples. Of the 25 positive isolates, the most frequently identified hypervirulence genes were iroB (64%, n = 16) and peg-344 (32%, n = 8), followed by rmpA (8%, n = 2) and iucA (8%, n = 2). The genes mrkD (100%, n = 25) and entB (92%, n = 23) were the most prevalent among all virulence genes. All positive samples carried at least one virulence gene. Notably, none of the samples tested positive for the K1, K2, or rmpA2 genes. The detection of isolates harboring virulence-associated genes confirms the circulation of highly virulent K. pneumoniae strains within poultry environments, presenting substantial risks to animal health and indicating potential occupational exposure among farm workers. Strengthening biosecurity, hygiene measures, and routine surveillance programs in poultry farms is urgently needed to curb hvKp transmission and mitigate its potential public health impact.