Proliferation of Antibiotic-Producing Bacteria and Concomitant Antibiotic Production as the Basis for the Antibiotic Activity of Jordan's Red Soils

Anecdotes, both historical and recent, recount the curing of skin infections, including diaper rash, by using red soils from the Hashemite Kingdom of Jordan. Following inoculation of red soils isolated from geographically separate areas of Jordan, Micrococcus luteus and Staphylococcus aureus were rapidly killed. Over the 3-week incubation period, the number of specific types of antibiotic-producing bacteria increased, and high antimicrobial activity (MIC, ∼10 μg/ml) was observed in methanol extracts of the inoculated red soils. Antibiotic-producing microorganisms whose numbers increased during incubation included actinomycetes, Lysobacter spp., and Bacillus spp. The actinomycetes produced actinomycin C₂ and actinomycin C₃. No myxobacteria or lytic bacteriophages with activity against either M. luteus or S. aureus were detected in either soil before or after inoculation and incubation. Although protozoa and amoebae were detected in the soils, the numbers were low and did not increase over the incubation period. These results suggest that the antibiotic activity of Jordan''s red soils is due to the proliferation of antibiotic-producing bacteria.There is a growing recognition of the pressing need for new antimicrobial agents for the treatment of infectious diseases (11, 38). As just one cogent example, new antibiotics are in high demand for the treatment of Staphylococcus aureus infections (25), particularly due to the emergence of methicillin-resistant S. aureus in communities and hospitals (25, 41). In addition, providing effective and affordable antibiotics to people in epidemic-prone developing countries remains a major challenge (37).Historically, natural products have played a key role in the discovery and development of many antibiotics (34). In particular, soil-based actinomycetes have been the source of countless drugs, such as streptomycin, actinomycin, erythromycin, and vancomycin, to name only a few (18). One approach to the discovery of new antimicrobial agents from natural sources has been to use folklore or historical records to guide the collection of samples (20).Through our ongoing studies of the biodiversity of the Hashemite Kingdom of Jordan (Jordan) (2-7, 35, 36), we were intrigued by anecdotes of the antibiotic-like properties of red soil, used historically for treating skin infections and diaper rash and still in use in some communities as an inexpensive alternative to pharmaceutical products. Within Jordan, there are four major biogeographic regions (8, 21), and red soils are most commonly found in the Mediterranean region of the northwestern portion of Jordan, near cities such as Irbid, Ramtha, and Ajloun. An area away from housing, preferably not touched by feet and thus considered clean, is chosen, and soil below the surface is collected, as the surface is considered contaminated or not clean. After the infected area of skin is washed and dried, the sieved soil is applied daily as either a powder or paste until the infection subsides. The basis for the antimicrobial activity of red soils is not known.Antimicrobial activity of soils against inoculated microorganisms has been attributed to abiotic or biotic factors. Abiotic activity has been shown to be responsible for the antimicrobial activities of clay minerals used in the treatment of a mycobacterial skin infection known as Buruli ulcer (28). Soil texture was found to influence the survival of Pseudomonas fluorescens and Bacillus subtilis in soil (40), while soil temperature and pH and the presence of roots affected the leaching of a genetically modified strain of P. fluorescens in soil (29). Biotic factors, including predation and antimicrobial-producing or lytic microorganisms, were suggested as mechanisms for killing microorganisms introduced into soils (1, 14, 31, 32). Prior inoculation of soil with one strain of P. fluorescens reduced the ability of a second P. fluorescens strain to colonize (19). A phenazine pigment produced by a P. fluorescens strain was shown to be responsible for biological control of a root disease of wheat caused by Gaeumannomyces graminis var. tritici (39), and it has been shown that filaments of the biocontrol fungus Trichoderma grow toward fungal pathogens and release antibiotics and lytic enzymes (9). With that background as a guide, we undertook an investigation to identify the basis for the antimicrobial activity of Jordan''s red soils.     

Micropropagation and production of arbutin in oriental strawberry tree (<Emphasis Type="Italic">Arbutus andrachne</Emphasis> L.)

A protocol for micropropagation of Arbutus andrachne from seeds was developed. Results indicated that none of the seeds cultured on Murashige and Skoog (MS) medium, with or without plant growth regulators (PGRs), germinated. Seeds soaked in 250 mg l⁻¹ gibberellic acid (GA₃) at 4°C for 3 days, then cultured on water-agar medium containing 2.0 mg l⁻¹ GA₃ exhibited 80–100% germination and developed into usable seedlings. Shoot proliferation was tested on MS or B5 medium containing different concentrations of cytokinin. No shoot proliferation was observed on PGR-free medium. Proliferation was more successful on MS than on B5 medium. On both media, the most successful proliferation was obtained using zeatin as a cytokinin type. Rooting was tested on MS medium containing different concentrations of auxin. Rooting failed on PGR-free medium and on medium containing indole-3-acetic acid (IAA), 0.25 or 0.5 mg l⁻¹ indole-3-butyric acid (IBA), or 0.25, 0.5 or 2.0 mg l⁻¹ α-naphthaleneacetic acid (NAA). Rooting (40%) was most successful with 1.0 mg l⁻¹ NAA. Rooted plantlets exhibited 80% survival in all mixtures of peatmoss and perlite, and acclimatized plants were successfully grown in the greenhouse. Quantitative analysis of arbutin performed on in vivo and in vitro leaves using high-performance liquid chromatography (HPLC) revealed that in vivo leaves contained higher arbutin content (0.3–0.81% w/w) than in vitro leaves (0.09% w/w). The highest yield of arbutin in vivo was detected in leaves collected in August, and the lowest yield in leaves collected in December.     

Developmental stages and gut microenvironments influence gut microbiota dynamics in the invasive beetle Popillia japonica Newman (Coleoptera: Scarabaeidae)

Popillia japonica Newman (Coleoptera: Scarabaeidae) is a highly polyphagous invasive beetle originating from Japan. This insect is highly resilient and able to rapidly adapt to new vegetation. Insect-associated microorganisms can play important roles in insect physiology, helping their hosts to adapt to changing conditions and potentially contributing to an insect's invasive potential. Such symbiotic bacteria can be part of a core microbiota that is stably transmitted throughout the host's life cycle or selectively recruited from the environment at each developmental stage. The aim of this study was to investigate the origin, stability and turnover of the bacterial communities associated with an invasive population of P. japonica from Italy. Our results demonstrate that soil microbes represent an important source of gut bacteria for P. japonica larvae, but as the insect develops, its gut microbiota richness and diversity decreased substantially, paralleled by changes in community composition. Notably, only 16.75% of the soil bacteria present in larvae are maintained until the adult stage. We further identified the micro-environments of different gut sections as an important factor shaping microbiota composition in this species, likely due to differences in pH, oxygen availability and redox potential. In addition, P. japonica also harboured a stable bacterial community across all developmental stages, consisting of taxa well known for the degradation of plant material, namely the families Ruminococcacae, Christensenellaceae and Lachnospiraceae. Interestingly, the family Christensenallaceae had so far been observed exclusively in humans. However, the Christensenellaceae operational taxonomic units found in P. japonica belong to different taxonomic clades within this family.     

CCR5 Expression Correlates with Susceptibility of Maturing Monocytes to Human Immunodeficiency Virus Type 1 Infection

The chemokine receptor CCR5 and to a lesser extent CCR3 and CCR2b have been shown to serve as coreceptors for human immunodeficiency virus type 1 (HIV-1) entry into blood- or tissue-derived macrophages. Therefore, we examined the expression of the chemokine receptors CCR1, CCR2b, CCR3, CCR5, and CXCR4 as RNAs or as membrane-expressed antigens in monocytes maturing into macrophages and correlated these results with the susceptibility of macrophages to HIV-1 infection, as measured by their concentrations of extracellular p24 antigen and levels of intracellular HIV DNA by quantitative PCR. There was little change in levels of CCR1, CCR2b, and CCR5 RNAs. CCR3 RNA and surface antigen were undetectable throughout maturation of adherent monocytes over 10 days. CXCR4 RNA and membrane antigen were strongly expressed in newly adherent monocytes, but their levels declined at day 7. The amounts of CCR5 RNA remained stable, but the amounts of CCR5 antigen increased from undetectable to peak levels at day 7 and then declined slightly at day 10. Levels of susceptibility to laboratory (HIV-1_BaL) and clinical strains of HIV-1 showed parallel kinetics, peaking at day 7 and then decreasing at days 10 to 14. The concordance of levels of HIV DNA and p24 antigen suggested that the changes in susceptibility with monocyte maturation were at or immediately after entry and correlated well with CCR5 expression and inversely with CXCR4 expression.     

Consanguineous marriage in a newly developed country: the Qatari population

This study examines the frequency of consanguineous marriage and coefficient of inbreeding in the State of Qatar. The study was conducted in semi-urban areas of Doha between January and May 2004. A sample of 1515 married Qatari females aged 15 years and over participated. The degree of consanguinity between each female and her spouse, and degree of consanguinity between their parents were recorded. The rate of consanguinity in the present generation was high (54.0%) with a coefficient of inbreeding of 0.02706. The commonest type of consanguineous marriage was between first cousins (34.8%). Double first cousin marriages were common (3.1%) compared with other populations. The consanguinity rate in the State of Qatar has increased from 41.8% to 54.5% in one generation.     

Phytochemical and biological investigation of Aristolochia maurorum L

Aristolochia maurorum L. of Jordanian origin has been investigated phytochemically, quantitatively, and biologically. Three atypical alkaloids, namely aristolochic acid I (1), aristolochic acid II (2) and aristolochic acid IIIa (3), have been isolated and identified. Of these known 1-phenanthrenecarboxylic acids, 2 and 3 are reported for the first time from this species. The identified compounds 1-3 were first evaluated biologically as cytotoxic agents against the brine shrimp lethality test (BST), in which compound 1 was found to be the most potent (LC50, 4.9 microg/mL). The antiplatelet activity of the methanolic extracts, the acidic fractions of aerial and root parts, and the identified compounds 1-3 were evaluated using an automatic platelet aggregometer and coagulation tracer (APACT 2). Using external reference standards, and a reverse-phase isocratic method, the distribution of aristolochic acid I and aristolochic acid II in different plant parts of Aristolochia maurorum L. during flowering stage was analyzed by PDA-HPLC. A quantitative comparison between two previously reported extraction methods was also made. Roots were found to be the main storage of aristolochic acid I and aristolochic acid II during flowering stage with about 0.22 and 0.108% (w/w), respectively.     

Vaccination with attenuated Salmonella enterica Dublin expressing E coli O157:H7 outer membrane protein Intimin induces transient reduction of fecal shedding of E coli O157:H7 in cattle

Background  

Escherichia coli serogroup O157:H7 has emerged as an important zoonotic bacterial pathogen, causing a range of symptoms from self-limiting bloody diarrhea to severe hemorrhagic colitis and hemolytic-uremic syndrome in humans. Beef and dairy cattle are considered the most important animal reservoirs for this pathogen. One of the important virulence characteristics of E. coli O157:H7 is the eaeA gene encoding the 97 kDa surface protein intimin. Intimin is required for attachment and effacement during the interaction of enterohemorrhagic E. coli with human and bovine neonatal enterocytes. The present study was undertaken to test the hypothesis that an adaptive mucosal immune response directed against intimin will reduce or prevent enteric colonization and fecal shedding of E. coli O157:H7 in cattle.     

Two bioactive mono-tetrahydrofuran acetogenins, annoglacins A and B, from Annona glabra

Two new bioactive mono-THF Annonaceous acetogenins, annoglacins A and B, have been isolated from the fractionated ethanolic extracts of the leaves of Annona glabra, directing the fractionation with the brine shrimp lethality test (BST). Their structures were elucidated based on spectroscopic and chemical methods and the absolute stereochemistries were determined by the advanced Mosher ester method. Annoglacins A and B were selectively 1000 and 10,000 times, respectively, more potent than adriamycin against the human breast carcinoma (MCF-7) and pancreatic carcinoma (PACA-2) cell lines in our panel of six human solid tumor cell lines.     

Neosetophomone B induces apoptosis in multiple myeloma cells via targeting of AKT/SKP2 signaling pathway

Multiple myeloma (MM) is a hematologic malignancy associated with malignant plasma cell proliferation in the bone marrow. Despite the available treatments, drug resistance and adverse side effects pose significant challenges, underscoring the need for alternative therapeutic strategies. Natural products, like the fungal metabolite neosetophomone B (NSP-B), have emerged as potential therapeutic agents due to their bioactive properties. Our study investigated NSP-B's antitumor effects on MM cell lines (U266 and RPMI8226) and the involved molecular mechanisms. NSP-B demonstrated significant growth inhibition and apoptotic induction, triggered by reduced AKT activation and downregulation of the inhibitors of apoptotic proteins and S-phase kinase protein. This was accompanied by an upregulation of p21Kip1 and p27Cip1 and an elevated Bax/BCL2 ratio, culminating in caspase-dependent apoptosis. Interestingly, NSP-B also enhanced the cytotoxicity of bortezomib (BTZ), an existing MM treatment. Overall, our findings demonstrated that NSP-B induces caspase-dependent apoptosis, increases cell damage, and suppresses MM cell proliferation while improving the cytotoxic impact of BTZ. These findings suggest that NSP-B can be used alone or in combination with other medicines to treat MM, highlighting its importance as a promising phytoconstituent in cancer therapy.     

Mapping of sample collection data: GIS tools for the natural product researcher

Scientists engaged in the research of natural products often either conduct field collections themselves or collaborate with partners who do, such as botanists, mycologists, or SCUBA divers. The information gleaned from such collecting trips (e.g. longitude/latitude coordinates, geography, elevation, and a multitude of other field observations) have provided valuable data to the scientific community (e.g., biodiversity), even if it is tangential to the direct aims of the natural products research, which are often focused on drug discovery and/or chemical ecology. Geographic Information Systems (GIS) have been used to display, manage, and analyze geographic data, including collection sites for natural products. However, to the uninitiated, these tools are often beyond the financial and/or computational means of the natural product scientist. With new, free, and easy-to-use geospatial visualization tools, such as Google Earth, mapping and geographic imaging of sampling data are now within the reach of natural products scientists. The goals of the present study were to develop simple tools that are tailored for the natural products setting, thereby presenting a means to map such information, particularly via open source software like Google Earth.