Characterisation of Pseudomonas aeruginosa related to bovine mastitis

Abstract

Pseudomonas aeruginosa is one of the causative pathogens of bovine mastitis. Most P. aeruginosa strains possess the type III secretion system (TTSS), which may increase somatic cell counts (SCCs) in milk from mastitis-affected cows. Moreover, most of P. aeruginosa cells can form biofilms, thereby reducing antibiotic efficacy. In this study, the presence and effect of TTSS-related genotypes on increase of SCCs among 122 P. aeruginosa isolates obtained from raw milk samples from mastitisaffected cows and their antibiotic susceptibility at planktonic and biofilm status were investigated. Based on the presence of TTSS-related genes a total of 82.7% of the isolates were found to harbour exoU and/or exoS genes, including the invasive (exoU-/ exoS+, 69.4%), cytotoxic (exoU+/exoS-, 8.3%) and cytotoxic/invasive strains (exoU+/ exoS+, 5.0%). Milk containing exoS-positive isolates had higher SCCs than those containing exoS-negative isolates. The majority of isolates showed gentamicin, amikacin, meropenem and ciprofloxacin susceptibility at planktonic status. However, the susceptibility was decreased at the biofilm status. Based on minimum biofilm eradication concentration (MBEC)/minimum inhibitory concentration (MIC) ratios, the range of change in antibiotic susceptibility varied widely depending on the antibiotics (from ≥ 3.1-fold to ≥ 475.0-fold). In conclusion, most P. aeruginosa isolates studied here had a genotype related to increase in SCCs. The efficiency of antibiotic therapy against P. aeruginosa-related bovine mastitis could be improved by analysing both the MBEC and the MIC of isolates.

Couples' urinary bisphenol A and phthalate metabolite concentrations and the secondary sex ratio

“…If hormonal imbalance caused by environmental factors generates non-optimally matured oocytes with coexisting non-optimally liquefied cervical mucus, preferential fertilization of the oocyte by Y-bearing sperm may be facilitated, which, in turn, may result in the selective loss of male embryos (Jongbloet, 2004). Our findings and scarce experimental evidence on the effects of BPA and phthalates on sex ratio may be a consequence of hormonal imbalance, though our findings are limited by the absence of preconceptional hormonal data (Izumi et al, 2008; Jarmołowicz et al, 2014). …”

A Metataxonomic Approach Could Be Considered for Cattle Clinical Mastitis Diagnostics

“…P. azotoformans , found in one cow and exhibiting a relative abundance increase of 8.1, has not been identified as causative of bovine mastitis, but other Pseudomonas spp. such as Pseudomonas aeruginosa , have been (44). …”

Bovine esophageal and glossal ulceration associated with <i>Pseudomonas aeruginosa</i> and <i>Fusobacterium</i> spp. in a 10-month-old Holstein heifer

“…A large number of hospital outbreaks have been linked to environmental sources, particularly water systems [ 3 , 27 ]. The species can evidently rapidly acquire resistance to various antimicrobial agents, and is capable of forming a biofilm [ 18 , 21 ], which acts as a direct barrier to phagocytic cells and offers innate resistance to antibiotics and disinfectants [ 10 ]. Most P. aeruginosa infections are difficult to treat because of the pathogen’s ability to resist many structurally unrelated antibiotics via both intrinsic and acquired antibiotic resistance mechanisms [ 13 ].…”

“…P. aeruginosa is not only a recognized human pathogen but also a verified animal pathogen. It is one of the major causes of diseases such as otitis [ 12 ], mastitis [ 2 , 17 , 18 , 22 , 31 ], endometritis [ 1 , 9 ], and hemorrhagic pneumonia [ 5 , 20 ] in both livestock and domestic pets. Recent reports associated with P. aeruginosa infection in cattle are restricted to those describing mastitis without histopathological analysis [ 2 , 17 , 18 ].…”

“…P. aeruginosa has been reported to cause endometritis [ 1 , 9 ] and keratitis [ 26 ] in horses, external otitis in dogs [ 12 ], hemorrhagic pneumonia in minks [ 5 , 20 ], and mastitis in cows [ 2 , 17 , 18 ] and goats [ 22 , 31 ]. Although the organism has been infrequently isolated in cases of bovine and goat mastitis [ 2 , 17 , 18 , 22 , 31 ], there are no reports of severe esophageal and glossal ulceration in agricultural livestock, including cattle.…”