Increased prevalence of indoor and species is associated with indoor flooding and coastal proximity: a case study of 28 moldy buildings.

Indoor flooding is a leading contributor to indoor dampness and the associated mold infestations in the coastal United States. Whether the prevalent mold genera that infest the coastal flood-prone buildings are different from those not flood-prone is unknown. In the current case study of 28 mold-infested buildings across the U.

Incidence of Listeria monocytogenes and Listeria spp. in a small-scale mushroom production facility.

Listeria monocytogenes is a foodborne pathogen of significant concern to the agricultural and food processing industry because of its ability to grow and persist in cool and moist environments and its association with listeriosis, a disease with a very high mortality rate. Although there have been no listeriosis outbreaks attributed to fresh mushrooms in the United States, retail surveys and recalls are evidence that L. monocytogenes contamination of mushrooms (Agaricus bisporus) can occur.

Novel epidemic clones of Listeria monocytogenes, United States, 2011.

We identified a novel serotype 1/2a outbreak strain and 2 novel epidemic clones of Listeria monocytogenes while investigating a foodborne outbreak of listeriosis associated with consumption of cantaloupe during 2011 in the United States. Comparative analyses of strains worldwide are essential to identification of novel outbreak strains and epidemic clones.

Klebsiella michiganensis sp. nov., a new bacterium isolated from a tooth brush holder.

Isolate W14(T) recovered from a household tooth brush holder was found to be gram-negative, a facultative anaerobic, non-motile, capsulated, and a non-endospore-forming straight rod. Based on phylogenetic analysis with 16S rRNA gene sequence, isolate W14(T) was affiliated to the genus Klebsiella. The closest phylogenetic relative was K.

A combined multi-virulence-locus sequence typing and Staphylococcal Cassette Chromosome mec typing scheme possesses enhanced discriminatory power for genotyping MRSA.

Methicillin-resistant Staphylococcus aureus (MRSA) remains a major threat to human populations worldwide. Knowing the extent of MRSA genetic diversity within a healthcare facility may provide important insights into the epidemiology of this important pathogen. MRSA isolates recovered from nasal swabs of patients entering the Intensive Care Unit of the Penn State Milton S.

Sequence typing confirms that a predominant Listeria monocytogenes clone caused human listeriosis cases and outbreaks in Canada from 1988 to 2010.

Human listeriosis outbreaks in Canada have been predominantly caused by serotype 1/2a isolates with highly similar pulsed-field gel electrophoresis (PFGE) patterns. Multilocus sequence typing (MLST) and multi-virulence-locus sequence typing (MVLST) each identified a diverse population of Listeria monocytogenes isolates, and within that, both methods had congruent subtypes that substantiated a predominant clone (clonal complex 8; virulence type 59; proposed epidemic clone 5 [ECV]) that has been causing human illness across Canada for more than 2 decades.

Molecular evolutionary and epidemiological dynamics of a highly pathogenic fish rhabdovirus, the spring viremia of carp virus (SVCV).

Spring viremia of carp virus (SVCV), which causes an acute hemorrhagic and highly contagious disease in cyprinids, was first described in Europe and subsequently reported in parts of Asia and North America. SVCV can be classified into four genogroups: Ia, Ib, Ic, and Id. While Ia and Id have wide circulation and are reported to cause outbreaks in North America and Europe, respectively, Ib and Ic were last reported in the 1980s.

A novel multiplex PCR method for detecting the major clonal complexes of MRSA in nasal isolates from a Pennsylvania hospital.

A novel multiplex PCR was developed which targeted virulence genes associated with the major clonal complexes (CCs) of healthcare- and community-associated methicillin-resistant Staphylococcus aureus (MRSA) in the USA. Most isolates (40/66) were identified as CC 5, while remaining isolates represented CCs 1, 8, 30, 45, 59, 133, and five isolates were not S. aureus.

comK prophage junction fragments as markers for Listeria monocytogenes genotypes unique to individual meat and poultry processing plants and a model for rapid niche-specific adaptation, biofilm formation, and persistence.

Different strains of Listeria monocytogenes are well known to persist in individual food processing plants and to contaminate foods for many years; however, the specific genotypic and phenotypic mechanisms responsible for persistence of these unique strains remain largely unknown. Based on sequences in comK prophage junction fragments, different strains of epidemic clones (ECs), which included ECII, ECIII, and ECV, were identified and shown to be specific to individual meat and poultry processing plants. The comK prophage-containing strains showed significantly higher cell densities after incubation at 30°C for 48 h on meat and poultry food-conditioning films than did strains lacking the comK prophage (P < 0.

Dynamic evolutionary pattern of alpha2-macroglobulin in a model organism, the zebrafish (Danio rerio).

Studies of alpha-2-macroglobulin (alpha(2)M), a universal protease inhibitor, have indicated that it plays a unique and critical role in the innate immune system of vertebrate and invertebrate animals. The distinctive mechanism of pathogen inhibition--through physical entrapment of the pathogen-derived protease--makes alpha(2)M an ideal candidate for molecular evolutionary analysis. Furthermore, recent studies revealed that the Osteichthyes are characterized by levels of alpha(2)M diversification that exceed those recorded in other animal groups.

Molecular diversity and evolution of myticin-C antimicrobial peptide variants in the Mediterranean mussel, Mytilus galloprovincialis.

Mussels have diverse groups of cysteine rich, cationic antimicrobial peptides (AMPs) (defensins, mytilins, myticins, and mytimycin) that constitute an important component of their innate immune defence. Despite the identification and characterization of these AMPs in mussels, the underlying genetic mechanisms that maintain high diversity among multiple variants of the myticin-C isoform are poorly understood. Using phylogeny-based models of sequence evolution and several site-by-site frequency spectrum statistical tests for neutrality, herein we report that positive selection has been the major driving force in maintaining high diversity among the allelic-variants of the myticin-C AMP of Mytilus galloprovincialis.

Positive Darwinian selection on crustacean hyperglycemic hormone (CHH) of the green shore crab, Carcinus maenas.

The tissue-specific expression and differential function of the crustacean hyperglycemic hormone (CHH) in Carcinus maenas indicate an interesting evolutionary history. Previous studies have shown that CHH from the sinus gland X-organ (XO-type) has hyperglycemic activity, whereas the CHH from the pericardial organ (PO-type) neither shows hyperglycemic activity nor it inhibits Y-organ ecdysteroid synthesis. Here we examined the types of selective pressures operating on the variants of CHH in Carcinus maenas.

Detecting molecular adaptation at individual codons in the pattern recognition protein, lipopolysaccharide- and beta-1,3-glucan-binding protein of decapods.

Pattern recognition proteins play an important role in the innate immune response of invertebrates. Herein we report the evolutionary relationships among Gram-negative bacteria binding proteins (GNBPs) that were previously identified and characterized from a wide array of invertebrates. Our results, together with those obtained in previous studies, indicate that decapod lipopolysaccharide- and beta-1,3-glucan binding protein (LGBP/BGBP) has retained the crucial components for glucanase activity, and shares a common ancestor with GNBPs, as well as with the glucanase proteins of a wide range of invertebrates, rather than with GNBPs of some arthropods.

Detecting molecular adaptation at individual codons in the glycoprotein gene of the geographically diversified infectious hematopoietic necrosis virus, a fish rhabdovirus.

Salmonid fishes, the principal hosts of the infectious hematopoietic necrosis virus (IHNV), are a candidate species for aquaculture in many countries. IHNV causes an acute disease resulting in severe economic loss in salmonid fish farming. Previous phylogenetic analyses revealed the existence of multiple genogroups of this virus throughout the geographical range of its host.

Evidence for positive Darwinian selection on the hepcidin gene of Perciform and Pleuronectiform fishes.

Hepcidin is a small cysteine-rich peptide that plays an important role in antimicrobial activity and in maintaining iron homeostasis in vertebrates. Here we report on the underlying mechanism that maintains high sequence diversities among the hepcidin-like variants of perciform and pleuronectiform fishes. In contrast to mammals, maximum likelihood-based codon substitution analyses revealed that positive Darwinian selection (nonsynonymous to synonymous substitution, omega > 1) is the likely cause of accelerated rate of amino acid substitutions in the hepcidin mature peptide region of these fishes.

Positive natural selection in the evolution of human metapneumovirus attachment glycoprotein.

Human metapneumovirus (hMPV), a newly discovered virus of the family Paramyxoviridae, has been associated with upper and lower respiratory tract infections in different age groups in many countries. The putative attachment (G) glycoprotein of this virus was previously reported to have shown more extensive nucleotide and deduced amino acid sequence polymorphism than any other genomic regions of this virus, leading to four sub-lineages. Using a maximum likelihood-based codon substitution model of sequence evolution, here we report that sequences of extracellular domain of 8 amino acid sites in lineage 1a, and 3 amino acid sites each in lineage 1b, 2a, and 2b have a higher rate of nonsynonymous substitutions (d(N)) than the synonymous substitutions (d(S)) with a posterior probability above 0.

Effect of environmental parameters on immune response of the Indian spiny lobster, Panulirus homarus (Linnaeus, 1758).

The high export value of the Indian spiny lobster Panulirus homarus increasingly attracts the aquaculturists for farming and fattening. However, lack of knowledge on the effect of environmental parameters on the immune system of this animal could result in high mortality, which ultimately may cause major loss to the industry. Here, we report the effect of salinity (20, 25, 35, 40, and 45 per thousand), pH (5.

Adaptive evolution after duplication of penaeidin antimicrobial peptides.

Penaeidin antimicrobial peptides in penaeid shrimps are an important component of their innate immune system that provides immunity against infection caused by several gram-positive bacteria and filamentous fungal species. Despite the knowledge on the identification and characterization of these peptides in penaeid shrimps, little is known about the evolutionary pattern of these peptides and the underlying genetic mechanisms that maintain high sequence diversities in the penaeidin gene family. Based on the phylogenetic analyses and maximum likelihood-based codon substitution analyses, here we present the convincing evidence that multiple copies of penaeidins have evolved by gene duplication, and positive Darwinian selection (adaptive evolution) is the likely cause of accelerated rate of amino acid substitutions among these duplicated genes.

Detecting the form of selection in the outer membrane protein C of Enterobacter aerogenes strains and Salmonella species.

The types of selective pressure operating on the outer membrane protein C (ompC) of Enterobacter aerogenes strains, the causative agent for nosocomial infections, and Salmonella sp., the hazardous pathogen are investigated using the maximum likelihood-based codon substitution models. Although the rate of amino acid replacement to the silent substitution (omega) across the entire codon sites of ompC of E.

Pattern of nucleotide substitution and divergence of prophenoloxidase in decapods.

Despite the unprecedented development in identification and characterization of prophenoloxidase (proPO) in commercially important decapods, little is known about the evolutionary relationship, rate of amino acid replacement and differential selection pressures operating on proPO of different species of decapods. Here we report the evolutionary relationship among these nine decapod species based on proPO gene and types of selective pressures operating on proPO codon sites. Our analyses revealed that all the nine decapod species shared a common ancestor.