Microbial Minimalism: Genome Reduction in Bacterial Pathogens

When bacterial lineages make the transition from free-living or facultatively parasitic life cycles to permanent associations with hosts, they undergo a serious loss of genes and DNA. Complete genome sequences are providing an understanding of how extreme genome reduction affects evolutionary directions and metabolic capabilities of obligate pathogens and symbionts. [1]

Human macrophage activation programs induced by bacterial pathogens

Understanding the response of innate immune cells to pathogens may provide insights to host defenses and therefore the tactics employed by pathogens to bypass these defenses. We used DNA microarrays to explore the responses of human macrophages to a spread of bacteria. Macrophages skilled a broad range of bacteria with a strong, shared pattern of organic phenomenon. The shared response includes genes encoding receptors, signal transduction molecules, and transcription factors. This shared activation program transforms the macrophage into a cell primed to interact with its environment and to mount an immune reaction. Further study revealed that the activation program is induced by bacterial components that are Toll-like receptor agonists, including lipopolysaccharide, lipoteichoic acid, muramyl dipeptide, and warmth shock proteins. [2]

Exploitation of Mammalian Host Cell Functions by Bacterial Pathogens

Interest in bacterial pathogenesis has recently increased due to antibiotic resistance, the emergence of latest pathogens and therefore the resurgence of old ones, and therefore the lack of effective therapeutics. The molecular and cellular mechanisms of microbial pathogenesis are currently being defined, with precise knowledge of both the common strategies employed by multiple pathogenic bacteria and therefore the unique tactics evolved by individual species to assist establish infection. what’s emerging may be a new appreciation of how bacterial pathogens interact with host cells. Many host cell functions, including signal transduction pathways, cytoskeletal rearrangements, and vacuolar trafficking, are exploited, and these are the main target of this review. A bonus of this work is that bacterial virulence factors are providing new tools to review various aspects of mammalian cell functions, additionally to mechanisms of bacterial disease. [3]

Structure-Guided Design of a Fluorescent Probe for the Visualization of FtsZ in Clinically Important Gram-Positive and Gram-Negative Bacterial Pathogens

Addressing the growing problem of antibiotic resistance requires the event of latest drugs with novel antibacterial targets. FtsZ has been identified as an appealing new target for antibacterial agents. Here, we describe the structure-guided design of a replacement fluorescent probe (BOFP) during which a BODIPY fluorophore has been conjugated to an oxazole-benzamide FtsZ inhibitor. Crystallographic studies have enabled us to spot the optimal position for tethering the fluorophore that facilitates the high-affinity FtsZ binding of BOFP. [4]

Epidemiological Pattern of Non-fermenting Metallo Beta Lactamase Producing Bacterial Pathogens Isolated from Clinical Specimens in a Tertiary Care Hospital in Kakinada, India

Background: Non-fermentative Gram negative bacilli are known causative pathogens liable for hospital associated infection and responsible high morbidity and deathrate across all genders and ages.

Objectives: This study examined the prevalence of Non-fermentative Gram negative isolates expressing Metallo beta-lactamase isolates (NFGNB-MBL) among carbapenem-resistant isolated from clinical specimens and therefore the epidemiological pattern (Age, Sex and Source of infection).

Methodology: a complete of 250 clinical specimens from diverse infections were collected and analyzed, using standard microbiological methods. For MBL detection, two previously described methods were employed i.e. Imipenem-EDTA combined disc test and Imipenem-EDTA double disc synergy test (DDST). [5]

Reference

[1] Moran, N.A., 2002. Microbial minimalism: genome reduction in bacterial pathogens. Cell, 108(5), (Web Link)

[2] Nau, G.J., Richmond, J.F., Schlesinger, A., Jennings, E.G., Lander, E.S. and Young, R.A., 2002. Human macrophage activation programs induced by bacterial pathogens. Proceedings of the National Academy of Sciences, 99(3), (Web Link)

[3] Finlay, B.B. and Cossart, P., 1997. Exploitation of mammalian host cell functions by bacterial pathogens. Science, 276(5313), (Web Link)

[4] Structure-Guided Design of a Fluorescent Probe for the Visualization of FtsZ in Clinically Important Gram-Positive and Gram-Negative Bacterial Pathogens
Edgar Ferrer-González, Junso Fujita, Takuya Yoshizawa, Julia M. Nelson, Alyssa J. Pilch, Elani Hillman, Mayuki Ozawa, Natsuko Kuroda, Hassan M. Al-Tameemi, Jeffrey M. Boyd, Edmond J. LaVoie, Hiroyoshi Matsumura & Daniel S. Pilch
Scientific Reports volume 9, (Web Link)

[5] Rani, P. U. and Vijayalakshmi, P. (2017) “Epidemiological Pattern of Non-fermenting Metallo Beta Lactamase Producing Bacterial Pathogens Isolated from Clinical Specimens in a Tertiary Care Hospital in Kakinada, India”, Microbiology Research Journal International, 18(3), (Web Link)