Exploration of Klebsiella aerogenes derived secondary metabolites and their antibacterial activities against multidrug-resistant bacteria.

As the effectiveness of current treatments against the development of antimicrobial resistance is declining, new strategies are required. A great source of novel secondary metabolites with therapeutics effects are the endophytic bacteria present in medicinal plants. In this study, Klebsiella aerogenes (an endophytic bacteria belonging to the Enterobacteriaceae family) was isolated from Kalanchoe blossfeldiana (a medicinal plant". The bacterial secondary metabolites were identified using GC-MS techniques. Furthermore, the antibacterial potentials were investigated against multi-drug resistance (MDR) Salmonella typhi and Staphylococcus aureus. The GC-MS chromatogram of K. aerogenes secondary metabolites extract displayed total of 36 compounds. Ethyl acetate extracts of K. aerogenes, showed mean zone of growth inhibition of 15.00 ± 1.00 against S. typhi and 7.00 ± 1.00mm against S. aureus, respectively. The extract demonstrated significant antibacterial effectiveness against S. typhi and moderate antibacterial efficacy against S. aureus, with minimum inhibitory concentration (MIC) values ranging from 0.089 to 0.39 mg/mL. The time-kill kinetics profile of the ethyl acetate extract against S. typhi revealed a decrease in the number of viable cells during the initial 5, 6, and 24 hours. Conversely, there was a sudden increase in viable cells up to 6 hours for S. aureus. The identified secondary metabolite with high percentage than others, benzeneethanamine exhibited favorable interactions (-7.2 kcal/mol) with the penicillin-binding protein (PBP2a) of S. aureus and (-7.5 kcal/mol) osmoporin (OmpC) of S. typhi, indicating its potential as a candidate for drug development against these MDR bacteria. This study reported for the first time, bacterial endophytes associated with K. blossfeldiana with antibacterial activities.

Genomic diversity and nutritional analysis of multi-drug resistant extended spectrum ß-lactamase Producing-Klebsiella pneumoniae genes isolated from mastitic cattle milk in district peshawar, Pakistan.

The increasing incidence of resistance extended spectrum-beta lactamase (ESBL) producing Klebsiella pneumonia become worldwide issue. The current study aimed to determine the genomic diversity of ESBL-producing K. pneumoniae in milk samples collected from cows with mastitis as well as their antibiotic sensitivity profiles and genetic identification in Peshawar, Pakistan. The california mastitis test (CMT) was initially used to verify the presence for mastitis in 700 collected milk samples. The molecular identification of the 16SrRNA gene confirmed 120/700 (17.14 %) propagation of K. pneumonia. Out of these isolates MDR ESBL-producing isolates were 60/120 (50 %). The lactose were found (M = 3.96 ± 0.28, SD = 2.19), followed by fats (M = 3.12 ± 0.11, SD = 0.90), protein (M = 5.97 ± 0.24, SD = 1.84), sodium (M = 55.74 ± 2.07, SD = 15.81), potassium (M = 138.5 ± 1.53, SD = 11.71), chloride (M = 0.74 ± 0.03, SD = 0.24), calcium (M = 10.27 ± 0.31, SD = 2.42), and chlorine (M = 2.80 ± 0.22, SD = 1.70), respectively. Amikacin (80 %), ceftazidime (71 %), and tetracycline (71 %) were shown to be the most effective antimicrobials against all of the isolates. The occurrence of the blaSHV gene was observed at 56.00 % whereas the blaTEM gene and blaCTX-M gene were 36.00 %, and 30.00 %. The distribution of blaCTX-M subgroup genes was followed by blaCTX-M-1 (38.00 %), blaCTX-M-9 (22.20 %), and blaCTX-M-15 (61.10 %). Co-occurrence of blaCTX-M+ blaSHV was (15.00 %), blaCTX-M+ blaTEM were (6.60 %), and blaSHV + blaTEM were (10.00 %), respectively. The inappropriate, prolonged and common use of antibiotics may apply selective pressure for propagation and the occurrence of resistant isolates.

Correction: Nutritional analysis and characterization of carbapenemase producing-Klebsiella pneumoniae resistant genes associated with bovine mastitis infected cow's milk.

[This corrects the article DOI: 10.1371/journal.pone.0293477.].

Nutritional analysis and characterization of carbapenemase producing-Klebsiella pneumoniae resistant genes associated with bovine mastitis infected cow's milk.

The current study was designed to analyze nutritional parameters and to characterize carbapenemase producing-Klebsiella pneumoniae isolates from bovine mastitic cow's milk. Out of 700 milk samples K. pneumoniae was identified by phenotypic and molecular techniques along with their antibiogram analysis and nutritional analysis was performed using the procedure of Association of Official Analytical Chemists. Carbapenemase-producing K. pneumoniae was detected by phenotypic CarbaNP test followed by molecular characterization of their associated resistant genes blaVIM, blaKPC, blaOXA-48, blaNDM, and blaIMP along with insertion sequence common region 1 (ISCR1) and integrons (Int1, Int2, and Int3) genes. Among nutritional parameters, fat content was observed (2.99%) followed by protein (2.78%), lactose (4.32%), and total solid (11.34%), respectively. The prevalence of K. pneumoniae among bovine mastitis was found 25.71%. Antibiogram analysis revealed that more effective antibiotics was ceftazidime (80%) followed by amikacin (72%), while highly resistant antibiotics was Fusidic acid (100%). Distribution of carbapenemase producer K. pneumoniae was found 44.4%. Among carbapenem resistant genes blaKPC was found 11.25%, blaVIM 2.75%, blaNDM 17.5%, and blaOXA-48 7.5%, while blaIMP gene was not detected. Furthermore, distribution of ISCR1 was found 40%, while integron 1 was found 61.2% followed by integron 2 (20%), and integron 3 (5%). In conclusion, the recent scenario of carbapenemase resistant K. pneumoniae isolates responsible for mastitis may affect not only the current treatment regime but also possess a serious threat to public health due to its food borne transmission and zoonotic potential.

The contemporary immunoassays for HIV diagnosis: a concise overview.

Recent advances in human immunodeficiency virus (HIV) diagnostics have improved the management of disease progression significantly, which have also boosted the efficacy of antiviral therapies. The detection of HIV at the earliest is very important. A highly recognized and effective virological biomarker for acute HIV infections is p24 antigen. This brief overview is based on advances of HIV diagnosis while focusing on the latest HIV testing technologies including HIV-specific antigens detecting assays of both anti-HIV antibodies and p24 antigen. In addition to other emerging molecular diagnostics for acute HIV infection, the utilization of p24 antigen has been summarized. Moreover, it has been explained how these immunoassays have reduced the window period for detection of HIV in the acute stage of infection.

Multidrug resistant Klebsiella Pneumoniae reservoir and their capsular resistance genes in cow farms of district Peshawar, Pakistan.

Klebsiella pneumoniae is a major zoonotic pathogen that causes a variety of severe illnesses as well as mastitis. The distribution of mastitis-causing K. Pneumoniae and its virulence factors vary by country and geographical location. The present study aimed to find out the occurrence of Multidrug-resistant (MDR) K. Pneumoniae and their capsular resistance genes which were undocumented previously in cow farms of district Peshawar, Pakistan. A total of 700 milk samples from symptomatic mastitic cows were screened for MDR K. Pneumoniae. Furthermore, the characterization of capsular resistance genes was done by molecular techniques. Among these samples, K. pneumoniae was found 180/700 (25.7%), while MDR K. pneumoniae was found 80/180 (44.4%). The antibiogram analysis revealed high resistance to Vancomycin (95%) while highly sensitive to Ceftazidime (80%). The distribution of capsular genes shows the most common serotype K2 gene 39/80 (48.7%), followed by serotype K1 gene 34/80 (42.5%), serotype K5 17/80 (21.2%), and serotype K54 13/80 (16.2), respectively. Moreover, the co-occurrence of serotypes K1+K2 was found at 11.25%, KI+K5 was 05%, K1+K54 was 3.75%, and K2+K5 was 7.5%, respectively. A statistically significant association (p ≤ 0.05) was found between predicted and discovered K. pneumoniae values. In conclusion, the presence of MDR K. pneumoniae in combination with capsular genes may be a possible threat to dairy farm animals and humans in Peshawar, Pakistan. It may give us special attention to follow up on hygienic practices in livestock management.