Seroprevalence and molecular detection of brucellosis among Pakistani women with spontaneous abortion.

Background: Human brucellosis is a neglected disease transmitted to humans from animals such as cattle, goats, dogs, and swine. The causative agents are bacteria of the genus Brucella, intracellular pathogens usually confined to the reproductive organs of their animal hosts causing sterility and abortions. The objective of the study was to determine the seroprevalence of brucellosis among women with spontaneous abortions (SAW) and compare this seroprevalence with that of healthy pregnant women (HPW). Methods: The case-control study was designed to determine the seroprevalence and molecular detection of brucellosis in women who suffered from spontaneous abortion and healthy pregnant women of the Haripur District of Pakistan. A total of 770 blood samples (n = 385 for each group) were collected from 9 public and 11 private hospitals in Haripur District from December 2021-March 2023. Data on demographic features, epidemiological variables, and risk factors were collected from each participant by structured questionnaires. Initial screening for brucellosis was performed by Rose Bengal Plate Test followed by qRT-PCR for molecular detection of the genus-specific BCSP-31 gene of Brucella. Results: The study showed that anti-Brucella antibodies were more found in SAW 23.63% (91/385) than in HPW 1.29% (5/385). Brucella specific DNA was amplified in 89.01% (81/91) seropositive samples of SAW. Demographic features and risk factors such as age, urbanicity, socioeconomic status, education, occupation, and animal contact were found significantly associated with brucellosis (p ≤ 0.05). Consumption of unpasteurized raw milk (OR = 18.28, 95%CI: 8.16-40.94) was found highly concomitant with seroprevalence. Conclusion: This study reports the first evidence of involvement of brucellosis in spontaneous abortions in women of Pakistan. The study can be used to develop strategies for risk management during pregnancy, to raise awareness for brucellosis, and develop control programs.

European multi-centre study to establish MIC and zone diameter epidemiological cut-off values for Bacillusanthracis.

OBJECTIVES: Bacillus anthracis clinical breakpoints, representing a systematic approach to guide clinicians in selecting the most appropriate antimicrobial treatments, are not part of the guidance from the European Committee on Antimicrobial Susceptibility Testing (EUCAST). This is because defined distributions of MIC values and of epidemiological cut-off values (ECOFFs) have been lacking. In this study, a Europe-wide network of laboratories in collaboration with EUCAST, aimed at establishing standardized antimicrobial susceptibility testing methods, wild-type MIC distributions, and ECOFFs for ten therapeutically relevant antimicrobials. METHODS: About 335 B. anthracis isolates were tested by broth microdilution and disc diffusion methodologies. MIC and inhibition zone diameters were curated according to EUCAST SOP 10.2 and the results were submitted to EUCAST for ECOFFs and clinical breakpoint determination. RESULTS: Broth microdilution and disc diffusion data distributions revealed putative wild-type distributions for the tested agents. For each antimicrobial agent, ECOFFs were defined. Three highly resistant strains with MIC values of 32 mg/L benzylpenicillin were found. MIC values slightly above the defined ECOFFs were observed in a few isolates, indicating the presence of resistance mechanisms to doxycycline, tetracycline, and amoxicillin. DISCUSSION: B. anthracis antimicrobial susceptibility testing results were used by EUCAST to determine ECOFFs for ten antimicrobial agents. The MIC distributions were used in the process of determining clinical breakpoints. The ECOFFs can be used for the sensitive detection of isolates with resistance mechanisms, and for monitoring resistance development. Genetic changes causing phenotypic shifts in isolates displaying slightly elevated MICs remain to be investigated.

Differential antibrucella activity of bovine and murine macrophages.

Brucella abortus is an intracellular pathogen affecting macrophages. Macrophages release some antibrucella components such as lysozymes (LZ), reactive oxygen species (ROS) and reactive nitrite intermediates (RNI) which prevent intracellular survival of Brucella. The present study compared the antibrucella activity of bovine and murine macrophages following stimulation with B. abortus lipopolysaccharides. Our results revealed increased production of these antibrucella substances in murine macrophages as compared to bovine macrophages. The differential production of these antibrucella components explained the differential B. abortus killing ability of these species (bovine and mice) that was measured in terms of intramacrophagic survival of Brucellae in murine and bovine macrophages.