Issue cover
Research Article | 22 Oct 2026

Bacteriological and molecular characterization of mastitis-associated pathogens and milk quality in ewes and goats in Al-Kut, Iraq

Hayder Dawood Saleem1, Samih Riyadh Faisa2, Sammah Naeem Ghazi2, Zeid Muhsen Alsadoon3, and Anfal Jabbar Taher1 Show more
VETERINARY WORLD | Article No. 22 | pg no. 4669-4681 | Vol. 19, Issue 10 | DOI: 10.14202/vetworld.2026.4669-4681
Cited by 0
View PDF
View ePDF Download PDF

Cite this Article

  • APA
  • MLA
  • Chicago
  • Vancouver
  • Harvard

                            
                        


                    


                


            


            


            
        

              


                  

                      
ABSTRACT

                      
Background and Aim: Mastitis is an important health and production problem in small ruminants because it can impair udder health, milk yield, and milk quality. Integrated information on mastitis-associated bacterial pathogens and milk quality characteristics in sheep and goats in Al-Kut, Iraq, remains limited. This study aimed to determine the occurrence of California Mastitis Test (CMT)-positive milk samples in ewes and goats, assess N-acetyl-β-D-glucosaminidase (NAGase) reaction intensity, characterize associated bacterial pathogens using bacteriological and molecular methods, and evaluate selected milk quality parameters.
Materials and Methods: A cross-sectional study was conducted in Al-Kut, Wasit Province, Iraq, from February to August 2025. Milk samples were collected from 300 lactating small ruminants comprising 200 ewes and 100 goats aged 2–8 years. Samples were screened using CMT and a semi-quantitative NAGase colorimetric assay. CMT-positive samples underwent bacteriological culture and biochemical identification. Selected Staphylococcus aureus and Escherichia coli isolates were confirmed by polymerase chain reaction targeting the femA and phoA genes, respectively. Milk pH, electrical conductivity, protein, and fat contents were also evaluated.
Results: Overall, 145/300 (48.3%) samples were CMT-positive, with a higher proportion in ewes (113/200; 56.5%) than goats (32/100; 32.0%). Light NAGase reactions predominated among CMT-positive samples in both ewes (53/113; 46.9%) and goats (23/32; 71.9%). Among the 145 CMT-positive samples, 138 (95.2%) were culture-positive, with mixed bacterial infections accounting for 86/138 (62.3%).). Among individual bacterial findings, S. aureus was most frequent (16.9%), followed by E. coli (13.5%), coagulase-negative staphylococci (8.9%), and Streptococcus uberis (1.6%). Five S. aureus and five E. coli isolates selected for molecular confirmation yielded the expected femA (647 bp) and phoA (903 bp) amplicons, respectively. Electrical conductivity differed significantly between species and across age groups, whereas protein content showed a significant species effect. pH and fat content showed no significant effects in the revised analysis.
Conclusion: CMT-positive mastitis-related findings were more frequent in ewes than goats in the examined population, with mixed bacterial infections predominating among culture-positive samples. The detection of major mastitis-associated bacteria and molecular confirmation of selected S. aureus and E. coli isolates highlight the importance of bacteriological surveillance, early detection, and improved milking hygiene for mastitis control in small-ruminant farms in Al-Kut.
                      
Keywords: bacteriological characterization, California Mastitis Test, Escherichia coli, mastitis, milk quality, molecular diagnosis, small ruminants, Staphylococcus aureus.