The queen is not a pacemaker in the small-colony wasps Polistes instabilis and P. dominulus

2006 ◽  
Vol 71 (5) ◽  
pp. 1197-1203 ◽  
Author(s):  
Shalene Jha ◽  
Rowan G. Casey-Ford ◽  
Jes S. Pedersen ◽  
Thomas G. Platt ◽  
Rita Cervo ◽  
...  
Keyword(s):  
Small Colony ◽  
Polistes Instabilis

scholarly journals Functional genomics study of Pseudomonas putida to determine traits associated with avoidance of a myxobacterial predator

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shukria Akbar ◽  
D. Cole Stevens
Keyword(s):  
Pseudomonas Putida ◽  
Bacterial Communities ◽  
Predator Avoidance ◽  
Phenotypic Diversity ◽  
Myxococcus Xanthus ◽  
Predator Prey ◽  
Mucoid Conversion ◽  
Small Colony ◽  
Predator Prey Models ◽  
Insight Into

AbstractPredation contributes to the structure and diversity of microbial communities. Predatory myxobacteria are ubiquitous to a variety of microbial habitats and capably consume a broad diversity of microbial prey. Predator–prey experiments utilizing myxobacteria have provided details into predatory mechanisms and features that facilitate consumption of prey. However, prey resistance to myxobacterial predation remains underexplored, and prey resistances have been observed exclusively from predator–prey experiments that included the model myxobacterium Myxococcus xanthus. Utilizing a predator–prey pairing that instead included the myxobacterium, Cystobacter ferrugineus, with Pseudomonas putida as prey, we observed surviving phenotypes capable of eluding predation. Comparative transcriptomics between P. putida unexposed to C. ferrugineus and the survivor phenotype suggested that increased expression of efflux pumps, genes associated with mucoid conversion, and various membrane features contribute to predator avoidance. Unique features observed from the survivor phenotype when compared to the parent P. putida include small colony variation, efflux-mediated antibiotic resistance, phenazine-1-carboxylic acid production, and increased mucoid conversion. These results demonstrate the utility of myxobacterial predator–prey models and provide insight into prey resistances in response to predatory stress that might contribute to the phenotypic diversity and structure of bacterial communities.

Properties and control of cold-induced small colony variants of Staphylococcus aureus

2020 ◽  
pp. 100874
Author(s):  
Jiaju Qiao ◽  
Mengjiao Zhu ◽  
Yun Fan ◽  
Zhaoxin Lu ◽  
Fengxia Lv ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Small Colony Variants ◽  
Small Colony ◽  
And Control

Possible Transoceanic Rafting of Lepas Spp. on an Unopened Plastic Bottle of Chinese Origin Washed Ashore in Victoria, Australia

2021 ◽  
Vol 18 (1) ◽  
pp. 85-90
Author(s):  
Alexander Cooke ◽  
Huseyin Sumer
Keyword(s):  
Vibrio Parahaemolyticus ◽  
Vibrio Alginolyticus ◽  
Marine Debris ◽  
First Report ◽  
Environmental Threats ◽  
Plastic Bottle ◽  
Chinese Origin ◽  
The Pacific ◽  
Goose Barnacle ◽  
Small Colony

Floating marine debris and litter act as a vector transporting various species across long distances. The present study reports possible transoceanic rafting of a small colony of barnacles on an unopened plastic bottle of Chinese origin found washed ashore on the Ninety Mile Beach in Victoria, Australia. The crustaceans attached were identified to be the goose barnacle Lepas pectinata. Based on the number and size of the colony the marine pollutant was estimated to adrift for several months. We hypothesised the origin of the flotsam, especially the barnacles and how it made its way from the Pacific to be washed ashore in Australia. Furthermore, we identified two types of microbes, Vibrio alginolyticus and Vibrio parahaemolyticus, associated with the Lepas pectinata growing on the bottle. This study appears to be the first report of possible transoceanic rafting on unused plastic pollutants and highlights the potential environmental threats caused by plastic.

Ein pseudoallel-spezifischer Suppressor bei Salmonella typhimurium

1956 ◽  
Vol 11 (6) ◽  
pp. 317-329 ◽  
Author(s):  
P. Starlinger ◽  
F. Kaudewitz
Keyword(s):  
Salmonella Typhimurium ◽  
Uv Irradiation ◽  
Genetic Material ◽  
Suppressor Gene ◽  
Growth Characteristics ◽  
Suppressor Mutation ◽  
Deficient Mutant ◽  
Colony Type ◽  
Gene Concept ◽  
Small Colony

In Salmonella typhimurium, UV-irradiation of the histidine-deficient mutant hi-31 induced a slowly growing reversion to histidine-independence. This formed colonies much smaller than wildtype. By means of transduction the newly created character “small colony” was proved to be heritable. As demonstrated by the following experiments this was due to an independant suppressor-mutation (S-31). After UV-irradiation of hi-31/S-31 a small fraction of cells forming large colonies, revealed growth-characteristics of wildtype. After transduction of small colony type cells by phages raised on wildtype the same large colonies were obtained. Expected to be of genotype hi-31+/S-31, they were used as donor for transduction of hi-31. Both, large colonies (hi-31+/S-31) and small colonies (hi-31/S-31) were isolated, which proved to be stable in further transfers.26 histidin-requiring mutants, belonging to 4 groups, each of them characterised by the same block in histidine synthesis, were transduced with phage raised on hi-31/S-31. None of them exhibited changes of growth characteristics, resulting from the incorporation of the suppressor-gene. Thus the suppressor S-31 turned out to be pseudoallel-specific.This result is considered as evidence that pseudoalleles of the histidine series in Salmonella typhimurium not only are units of recombination but also of function of genetic material. The differences between levels of functions exhibited by units which have been called pseudoalleles by various investigators are discussed in connection with the gene concept.

scholarly journals Increased Expression of Clumping Factor and Fibronectin-Binding Proteins by hemB Mutants of Staphylococcus aureus Expressing Small Colony Variant Phenotypes

2002 ◽  
Vol 70 (10) ◽  
pp. 5428-5437 ◽  
Author(s):  
Pierre Vaudaux ◽  
Patrice Francois ◽  
Carmelo Bisognano ◽  
William L. Kelley ◽  
Daniel P. Lew ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Surface Display ◽  
Human Embryonic Kidney Cells ◽  
Small Colony Variant ◽  
Reverse Transcription Pcr ◽  
Bacterial Adhesins ◽  
Transport Chain ◽  
Complete Restoration ◽  
Small Colony ◽  
Slow Growing

ABSTRACT Small colony variants (SCVs) of Staphylococcus aureus are slow-growing subpopulations that cause persistent and relapsing infections. The altered phenotype of SCV can arise from defects in menadione or hemin biosynthesis, which disrupt the electron transport chain and decrease ATP concentrations. With SCVs, virulence is altered by a decrease in exotoxin production and susceptibility to various antibiotics, allowing their intracellular survival. The expression of bacterial adhesins by SCVs is poorly documented. We tested fibrinogen- and fibronectin-mediated adhesion of a hemB mutant of S. aureus 8325-4 that is defective for hemin biosynthesis and exhibits a complete SCV phenotype. In this strain, adhesion to fibrinogen and fibronectin was significantly higher than that of its isogenic, normally growing parent and correlated with the increased surface display of these adhesins as assessed by flow cytometry. Real-time quantitative reverse transcription-PCR demonstrated increased expression of clfA and fnb genes by the hemB mutant compared to its isogenic parent. The influence of the hemB mutation on altered adhesin expression was confirmed by showing complete restoration of the wild-type adhesive phenotype in the hemB mutant, either by complementing with intact hemB or by supplementing the growth medium with hemin. Increased surface display of fibrinogen and fibronectin adhesins by the hemB mutation occurred independently from agr, a major regulatory locus of virulence factors in S. aureus. Both agr-positive and agr-lacking hemB mutants were also more efficiently internalized by human embryonic kidney cells than were their isogenic controls, presumably because of increased surface display of their fibronectin adhesins.

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