Comparative study of the action of fluoroquinolones and vancomycin on biofilms of Staphylococcus strains isolated from infections of peritoneal dialysis catheters

Background: catheter mediated infections are mainly caused by Staphylococci, the treatment of these infections is challenging because of biofilm formation. Methods: A microtiter plate biofilm assay was used to study the in vitro activity of Vancomycin, Ofloxacin and Levofloxacin on preformed biofilms of 30 stains of Staphylococcus isolated from peritoneal dialysis catheters and fluids at concentrations like those used intraperitoneally. Results: The in vitro action of the three antibiotics on preformed biofilms was statistically significant. it was significantly higher for Ofloxacin and Levofloxacin rather than that of Vancomycin. Discussion: the results demonstrate the effectiveness of the three antibiotics at concentrations like those used intraperitoneally and the superiority of Fluoroquinolones activity on Staphylococcal biofilms, these results correlate with the conclusions of other authors.

Accuracy of SARS-CoV-2 molecular laboratory testing: insight on recurrence infection and the new emergent strains

The rapid spread of the SARS-CoV-2 virus and increased number of deaths urged the world to provide accurate diagnostic procedures and apply the correct prevention measures to eradicate the disease. Molecular assays are designed to test the presence of virus RNA. The assays have wanting accuracy represented by false positive and false negative results, in particularly with continuous emerging of SARS-CoV-2 genetic variability. Miss interpretation of the test results can lead to bad outcomes for both individuals and the surrounding community when assuming the test is perfect. This review provides an update of the currently available molecular laboratory methods and address the effect of ongoing SARS-CoV-2 genetic variability on the performance of RT-PCR, the problem of re-positive test result in recovered patients and provides elements to be considered for performing SARS-CoV-2 test and interpreting the test results.

Seroprevalence and risk factors of Mycoplasma capricolum subsp. capricolum among small ruminants in northern Jordan

During 2002-2003 the seroprevalence of Mycoplasma capricolum subsp. capricolum was studied among 104 small ruminant’s flocks (18 sheep, 27 goat and 59 mixed flocks) in northern Jordan. At least 5 serum samples/flock were tested using iELISA test. The true flock-level seroprevalences of Mycoplasma capricolum subsp. capricolum were 56%, 39%, 28% in small ruminant (sheep and goats), sheep and goats respectively. There was no significant difference (X2 = 2, d.f. =1, p = 0.15) between seroprevalences in sheep and goats at the flock level. A total of 29 variables including production and health management practices were tested as risk factors for seropositive flocks and analyzed using logistic regression analysis. The use of communal grazing was found to be a risk factor for Mycoplasma capricolum subsp. capricolum seropositivity with odds ratio of 5.2 and drinking the animals with spring water was a protective factor with odds ratio of 0.27. More than half of the examined flocks were seropositive to Mycoplasma capricolum subsp. capricolum indicating a role for Mycoplasma capricolum subsp. capricolum in contagious agalactiae in small ruminants. The education of farmers regarding the use of communal grazing and housing the newborn in separate barns is expected to help reducing the Mycoplasma capricolum subsp. capricolum infections in their flocks.

A Potential Bioactive Secondary Metabolites and Antimicrobial Efficacy of Streptomyces thermocarboxydus Strain KSA-2, Isolated from Kali River, Karwar

In the present study, an Actinomycetes strain KSA-2 was isolated from freshwater sediment samples of Kali River, Karwar, Karnataka, India. The strain KSA-2 was selected among seven isolates based on primary screening of antimicrobial activity against pathogenic organisms. The morphological physiological and biochemical characterizations were performed, the bioactive secondary metabolites were produced in liquid broth culture and was characterized by UV-Vis. spectroscopy and FTIR spectroscopy. Later, the potent KSA-2 strain was identified by 16S rRNA gene sequencing (1366 bp) and a phylogenetic tree was constructed and the strain KSA-2 was confirmed as Streptomyces thermocarboxydus strain KSA-2. Further, the characterization of methanolic extract by UV-Vis. and FTIR spectroscopy analysis revealed the presence of broad spectrum of antimicrobial and other compounds and alkyl halides, alkenes, sulfoxide, carboxylic acids, alkanes respectively.

Detection of RpoS Gene in Escherichia Coli O157:H7 and non-O157 and Their Survival Pattern in Water Treatment Methods

This study aimed to detect presence of RpoS gene in Escherichia coli O157:H7 and non-O157 and investigate their survival pattern in different water treatment methods. A total of fifteen serologically and molecularly identified E. coli was selected from a previous work, out of which eight were Escherichia coli O157 and seven were E. coli non-O157. From among these, S30 and S89 identified isolates served as presentative E. coli O157:H7 and non-O157 respectively for survival studies. The water treatment methods used employed included: use of silver, lime, storage, acidification (low pH), high temperature and Moringa oleifera. Survival pattern of the test organisms under the influence of these methods were carried out using standard techniques. Molecular detection of stress response gene, RpoS, in the fifteen (15) test organisms was performed following manufacturer’s instruction. Results showed that for both test organisms, silver was bactericidal at high concentration while storage allows their survival up till 21 days though with a reduction in cfu. Both organisms showed low survival at pH 9 while E. coli O157:H7 and non-O157 could survive at pH 4 and 6 respectively. E. coli O157:H7 survived better than non-O157 at high concentration of lime. While both survived at low temperature, E. coli O157:H7 survive better at 60oC. Sunlight and chlorine showed mild and complete bactericidal action respectively with increased exposure time for both test organisms. Moringa oleifera was only effective at a reduced concentration on the two organisms. Detection of RpoS genes showed that only 66.7% carried the gene in them while 33.3% did not. Findings from this study show that the possession of stressed genes in bacteria causing waterborne disease could allow these organisms to survive water treatment methods adopted in many under developed countries or rural communities. This suggests a threat to health of these communities.

Flock level seroprevalence of and risk factors for parainfluenza type 3 virus in small ruminants in northern Jordan

Background. Infectious diseases of the respiratory tract of farm animals are caused by a combination of infectious agents and predisposing factors. Parainfluenza virus type 3 is usually nominated as one of the causes. Seroprevalence and animal risk factors for PI3 infections were investigated in northern Jordan. Methods. The study involved 104 small ruminant flocks (18 sheep, 27 goats, and 59 mixed flocks sampled in northern Jordan. Indirect ELISA was used to test 678 blood samples used in this study. Flocks were identified as infected if at least 1 animal has been detected as positive by the ELISA test. Information regarding production and health management practices was collected in a questionnaire. Statistical analysis was conducted using the Statistical Package for Social Sciences software SPSS 23 (SPSS Inc., Chicago, IL, USA). Results. Flock-level and individual-level seroprevalences were 97%, 37%, and 76%, 11% in sheep and goats respectively. Multivariable logistic regression applied for production and health management practices showed significant risk factors for: Climatic zone (OR= 0.3) was decreasing risk factor for the PI3 seropositivity. Young separated from dams (OR= 4), neonatal deaths (OR= 3), and milking manual (OR= 37.5) were increasing risk factors for the seropositivity of PI3. Conclusions. PI3 virus has a high prevalence in sheep than goats and two risk factors could increase the prevalence of PI3 in both sheep and goats.

Bovine Tuberculosis in young heifer

A rare case of bovine tuberculosis in young heifer is reported. Miss diagnosed in several occasions due to lack of diagnostic tools. However; post-mortem lesion diagnosis is paramount. This case may pose public health concern to the farmer and his family.