scholarly journals Antibiotic resistance pattern and frequency of some beta lactamase genes in Klebsiella pneumoniae isolated from raw milk samples in Iran

2021 ◽  
Vol 71 (4) ◽  
pp. 2455
Author(s):  
E. ENFERAD ◽  
S. MAHDAVI

Klebsiella pneumoniae have become an important cause of mastitis in dairy cows. Resistance to beta lactam antibiotics resulted from beta lactamases enzyme production. The aim of this study was to investigate the antibiotic resistance pattern and frequency of some beta lactamase genes in Klebsiella pneumoniae isolated from raw milk samples in Iran. 200 raw cow milk samples were collected from different villages of north west of Iran. The samples were cultured and biochemical tests were performed for phenotypic diagnosis. Then, antibiotic resistance pattern was determined by antibiogram test. Finally, the presence of CTX, SHV and TEM genes in Klebsiella pneumoniae isolates was found by PCR method. Of total 200 raw cow milk samples, 80 samples (40%) contained Klebsiella pneumoniae. The frequency of CTX, SHV and TEM genes in Klebsiella pneumoniae isolates was 50 (62.5%), 34 (42.5%) and 70 (87.5%), respectively. 14 Klebsiella pneumoniae isolates (17.5%) possessed all three intended genes simultaneously. All strains of Klebsiella pneumoniae (100%) were resistant to ampicillin. The most strains were resistant to ceftriaxone (75%), gentamicin (70%) and nitrofurantoin (70%). 4 Klebsiella pneumoniae strains (5%) were resistant to all of tested antibiotics. The results showed high frequency of ESBLs and antibiotic resistance in Klebsiella pneumonia samples isolated from raw milk. It may occur exchange of resistance genes within and across species and with commensal bacteria of the human and animals.

Author(s):  
Khondaker Wahid Hasan ◽  
Nourin Tarannum ◽  
Sahana Parveen

The increase of pathogens in milk is threatening for the human beings. This is an investigation on overall microbiological analysis of raw and pasteurized milk as well as the milk-based beverages and also determining the antibiotic resistance pattern of isolated Escherichia coli and Staphylococcus aureus. A total of 100 samples (raw milk, pasteurized milk, mattha, lassi and laban) were taken from various locations of the capital city of Bangladesh, Dhaka. Total Viable Count, Total Coliform Count and Yeast and Moulds Count were performed as the microbiological inspection of selected samples. E.coli and Staphylococcus aureus were identified by conducting morphological analysis, gram-staining and biochemical tests. Antibiotic resistance pattern of isolated Escherichia Coli and Staphylococcus aureus were also detected with 11 commonly used antibiotics by conducting disc-diffusion method, following the CLSI guideline. The TVC range was the highest in raw milk samples (3.8×104 – 4.1×108 cfu/ml), and the lowest in pasteurized milk samples (1.2×102 – 5.4×103 cfu/ml), while 70% raw milk and 10% pasteurized milk samples strains were above the acceptable limit of Food and Drug Administration (FDA). Thirty-six Escherichia coli and thirty-two Staphylococcus aureus were isolated from all the 100 milk and milk-based beverage samples. The isolated Escherichia coli strains were most resistant to Penicillin G (81.58%), Erythromycin (78.94%) and Ampicillin (73.68%), and isolated Staphylococcus aureus strains were most resistant to Penicillin G (90.62%), Ampicillin (81.25%) and Methicillin (71.87%). respectively. Public awareness is needed to reduce the redundant use of antibiotics.


2021 ◽  
pp. 2410-2418
Author(s):  
Waleed Younis ◽  
Sabry Hassan ◽  
Hams M. A. Mohamed

Background and Aim: Raw milk is considered an essential source of nutrition during all stages of human life because it offers a valuable supply of protein and minerals. Importantly, milk is considered a good media for the growth and contamination of many pathogenic bacteria, especially food-borne pathogens such as Escherichia coli. Thus, the objective of this study was to characterize E. coli and detect its virulence factors and antibiotic resistance from raw milk samples. Materials and Methods: Raw milk samples (n=100) were collected from different localities in Qena, Egypt, and investigated for the presence of E. coli using different biochemical tests, IMViC tests, serotyping to detect somatic antigen type, and molecularly by polymerase chain reaction (PCR) tests. The presence of different virulence and antimicrobial genes (hly, eae, stx1, stx2, blaTEM, tetA(A), and tetB genes) in E. coli isolates was evaluated using PCR. Results: The results demonstrated that 10 out of 100 milk samples were contaminated with E. coli. Depending on serology, the isolates were classified as O114 (one isolate), O27 (two isolates), O111 (one isolate), O125 (two isolates), and untypeable (five isolates) E. coli. The sequencing of partially amplified 16S rRNA of the untypeable isolates resulted in one isolate, which was initially misidentified as untypeable E. coli but later proved as Enterobacter hormaechei. Moreover, antibacterial susceptibility analysis revealed that nearly all isolates were resistant to more than 3 families of antibiotics, particularly to β-lactams, clindamycin, and rifampin. PCR results demonstrated that all E. coli isolates showed an accurate amplicon for the blaTEM and tetA(A) genes, four isolates harbored eae gene, other four harbored tetB gene, and only one isolate exhibited a positive stx2 gene. Conclusion: Our study explored vital methods for identifying E. coli as a harmful pathogen of raw milk using 16S rRNA sequencing, phylogenetic analysis, and detection of virulence factors and antibiotic-resistant genes.


2016 ◽  
Vol 16 (1) ◽  
Author(s):  
Kamelia M. Osman ◽  
Ahmed Samir ◽  
Usama H. Abo-Shama ◽  
Essam H. Mohamed ◽  
Ahmed Orabi ◽  
...  

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