Antimicrobial Susceptibility Profile of <em>Klebsiella pneumoniae</em> Isolated as a Foodborne Pathogen From Some Dairy Products in Libya

Abstract

Klebsiella pneumoniae is one of the most common causes of clinical and asymptomatic mastitis in dairy cattle, also in milk and dairy products affecting its quality. Mastitis caused by K. pneumoniae is even more serious due to its poor response to antibiotic therapy. This study was conducted to detect and identify the presence of K. pneumoniae in milk and dairy products. A total of 234 samples were randomly collected from various locations in Libya. Samples were examined for the presence of K. pneumoniae by conventional cultural techniques that included cultivation in violet red bile agar plus 4-methylumbelliferyl-ß-D-glucuronide (VRBA + MUG) broth, and CHROM agar followed by identification by PCR and partial sequencing of 16S rRNA. Out of the 234 samples of milk and dairy products collected, 16 (6.8%) of the isolates revealed mucoid colonies on agar media phenotypically suggested to be K. pneumoniae. The isolates identification was confirmed by molecular techniques (16S rRNA). Among examined samples, K. pneumoniae was recovered from she camel’s milk, raw cow’s milk, raw fermented milk, Maasora cheese, Ricotta cheese, soft cheese, full cream milk powder, milk powder infant formula, cereal baby food and growing up formula. From the 16 K. pneumoniae isolates; antibiotic susceptibility testing was performed on 12 isolates, the results showed that K. pneumoniae isolates were resistant to more than 8 antibiotics, interestingly, two isolates revealed MBL production. This study emphasized the relationship between K. pneumoniae and raw milk, cheese, milk powder and infant milk retailed in Libya, which is considered as a risk for human health as many of these products did not comply with microbiological criteria of international and/or Libyan standards. The necessary precautions have to be taken to carry out effective sanitary practices during the production in dairy plants, handling and distribution in the markets particularly at local small manufacture scale.