54, days 1–5 after infection) In comparison, the rate of detecti

54, days 1–5 after infection). In comparison, the rate of detection of NS1 antigen was 22% for secondary infection and 23% for primary infection (Fisher’s exact test for NS1, p = 0.97 and, mean secondary IgG index = 3.8, mean primary IgG index = 2.1) at ≥11 days after onset of disease. Anti-DENV IgG antibodies levels at 1–5 days after

onset of disease did not appear to inhibit NS1 Ag detection. The results, however, suggest that rise in levels of antibodies may be in part responsible for the lower NS1 detection rates (IgM-NS1 Pearson correlation, r = −0.62, IgG-NS1 Pearson correlation, r = −0.45). Thus, the association between rising levels of IgG, including factors such as IgG in antigenemia clearance and immune complex formation, with lower assay Angiogenesis inhibitor sensitivity needs to be further clarified. The differences between the detection rates in primary and secondary infection for each serotype were not statistically significant (primary and secondary DENV-1, chi-squared, p = 0.07, p = 0.24, p = 0.71, and p = 0.66

for DENV-2, DENV-3, and DENV-4, respectively). The utility of the NS1 antigen ELISA was assessed using limited amounts of serum samples: 5 and 0.5 μL (Table 5). Of 53 confirmed positive samples, 50 (94%) serum samples were positive by NS1 antigen ELISA using 5 μL of sample. When serum samples with a Biorad NS1 index value ≥10 were analyzed, NS1 antigen detection rates were 100% (37/37) using CP-868596 purchase 5 μL of samples and 94% (31/33) with 0.5 μL (Table 5). When serum samples with a NS1 index value <10 were analyzed, detection rates were 81% (13/16) with 5 μL and 0% (0/10) with 0.5 μL. The differences between the NS1 antigen detection rates using 5 μL (1:10 dilution) of sample and undiluted samples were not statistically significant (Fisher's exact test, p = 0.24). In contrast, the differences were significant when 0.5 μL (1:100 dilution) was used (Fisher's exact test, p < 0.01, Table 5). Widespread DENV transmission associated with international travel and urbanization continues to pose a global

threat. As such, in addition to the current DENV diagnostic tools available, there is a tremendous need for reliable and dependable diagnostic tools that are relatively selleck chemical easy to use and that do not require highly skilled personnel or costly equipment. The dengue NS1 antigen ELISA is reported to be a promising tool for early dengue diagnosis.[13] While other investigators have reported the utility of various commercially available NS1 kits as a diagnostic tool for DENV infection,[14, 20-30] it is essential that their performance and utility be evaluated before their use becomes prevalent in different health sectors.[12] To determine the utility of the DENV NS1 assay for laboratory diagnosis of DENV infection of international travelers, we used serum samples from those who returned to Japan from various dengue endemic regions including Asia, Central and South America, Pacific Islands, and Africa.

, 2007; Shao et al, 2009) A close phylogenetic relationship, in

, 2007; Shao et al., 2009). A close phylogenetic relationship, in the same class of secondary metabolites belonging to polyketides, such as pigments, monacolins and citrinin, was found between Monascus spp. and other filamentous fungi, for example Penicillium and

Aspergillus spp.; therefore, we could anticipate similar, but more diverse functions in the aspects of growth, development and production Galunisertib research buy of secondary metabolites for G-proteins in Monascus spp., which might have implications for the handling and control of this group of beneficial microorganisms in fermentation. Monascus ruber wild-type strain M7 (Chen & Hu, 2005) was used to clone the Gα-subunit gene and generate the Mga1 knockout strains. All strains were maintained on potato dextrose agar (PDA) media at 28 °C. If required, hygromycin B was added to a concentration of 30 μg mL−1. For phenotypic characterization, conidial suspensions were selleckchem prepared on G25N agar medium and used as an inoculum, due to the lack of sporulation of Mga1 deletion strains on PDA. For liquid fermentation, a 1% spore suspension (105 spores mL−1) was inoculated in yeast extract sucrose (YES) medium and incubated at 28 °C without agitation (Blanc et al., 1995b). Fungal genomic DNA was isolated from mycelium grown on cellophane membranes covering PDA plates using the cetyltrimethylammonium

bromide method (Shao et al., 2009). Southern blot assays were performed using the DIG-High Prime DNA Labeling & Detection Starter kit I (Roche,

Germany). The procedure for amplifying the Gα-subunit gene is shown in Fig. 1a. The degenerate primer set GAF/GAR (Table 1) was designed based on conserved regions of various known fungal homologues. The optimal annealing temperature was determined by gradient PCR. PCR products of the predicted size were cloned into pMD18-T (Takara, Japan) and sequenced. The sequences thus obtained were Cytidine deaminase compared with the GenBank database using the blast program (http://blast.ncbi.nlm.nih.gov/Blast.cgi). The 5′ and 3′ flanking regions of the corresponding Gα-subunit gene fragment were amplified by single oligonucleotide nested (SON)-PCR (Antal et al., 2004). The inner and outer primers of nested PCR for SON-PCR are listed in Table 1. For target gene deletion, a gene disruption construct, carrying a hygromycin B resistance gene (hph) flanked by DNA sequences homologous to the sequences located at the 5′ and 3′ ends of Mga1 ORF, was amplified using the double-joint PCR method (Fig. 2a) (Yu et al., 2004). Briefly, the 5′ and 3′ flanking regions (648 and 884 bp, respectively) of Mga1 ORF were amplified with the primer pairs mgaK5f/mgaK5r and mgaK3f/mgaK3r, respectively (Table 1). The 2.1 kb hph marker cassette was amplified from the vector pSKH with the primer pair hphF/hphR, containing XbaI- and XhoI-restricted sites, respectively (Table 1).

Salome of The Hebrew University of Jerusalem, Israel, and Prof U

Salome of The Hebrew University of Jerusalem, Israel, and Prof. Ursula Kües and Dr Martin Ruhl of Georg-August-University Göttingen, Germany, for their assistance and helpful discussions to make simple and efficient transformation protocol in P. ostreatus. “
“Lactococcus garvieae check details is an important foodborne pathogen causing lactococcosis associated with hemorrhagic septicemia in fish worldwide. A real-time

quantitative polymerase chain reaction (qPCR) protocol targeting the 16S–23S rRNA intergenic spacer (ITS) region was developed for the detection and enum-eration of L. garvieae. The specificity was evaluated using genomic DNAs extracted from 66 cocci strains. Fourteen L. garvieae strains tested were positive, whereas 52 other strains including Lactococcus lactis ssp. lactis, Lactococcus lactis ssp. hordniae and Lactococcus lactis ssp. cremoris did not show a specific signal. The minimal limit of detection was 2.63 fg of purified genomic DNA, equivalent to 1 genome of L. garvieae. The optimized protocol was applied for the survey of L. garvieae in naturally contaminated fish samples. Our results suggest that the qPCR protocol using ITS is a sensitive and efficient tool for the rapid detection and enumeration of L. garvieae

in fish and fish-containing foods. “
“Acinetobacter baumannii plays a significant role in infecting patients admitted to hospitals. Many A. baumannii SB203580 infections, including ventilation-associated pneumonia, wound, and bloodstream infections, are common for intensive care and burn units. The ability of the microorganism to acquire resistance to many antibiotics, disinfectants, and dehydration

assures its long-term survival Sclareol in hospital settings. The application of bacteriophages is a potential tool to control A. baumannii infections. Bacteriophage AP22 lytic for A. baumannii was isolated from clinical materials and classified as a member of the Myoviridae family. The phage had an icosahedral head of 64 nm in diameter and a contractile tail of 85–90 nm in length. According to restriction analysis, AP22 had 46-kb double-stranded DNA genome. The phage AP22 exhibited rapid adsorption (> 99% adsorbed in 5 min), a large burst size (240 PFU per cell), and stability to the wide range of pH. The bacteriophage was shown to specifically infect and lyse 68% (89 of 130) genotype-varying multidrug-resistant clinical A. baumannii strains by forming clear zones. Thus, it could be used as a candidate for making up phage cocktails to control A. baumannii-associated nosocomial infections. Nosocomial infections and multidrug resistance of pathogens causing these infections are the growing and recognized problems in the modern healthcare system. Acinetobacter baumannii is a gram-negative, nonfermenting aerobic microorganism that plays a significant role in infecting patients admitted to hospitals.

5%) The study synbiotic, AKSB, did not demonstrate a preventativ

5%). The study synbiotic, AKSB, did not demonstrate a preventative effect against TD compared to placebo at the interim analysis (n = 174) and therefore study was halted. Although adherence to the study was less than expected, we also found no evidence that AKSB could reduce TD incidence in the 114 subjects who were fully protocol adherent. The study drug, AKSB, was found to be safe in all study participants including those older Olaparib order than 60 years (n = 46). We also demonstrated good viability

of organisms within unused capsules indicating that the AKSB synbiotic was of high quality. Probiotic studies for the prevention of TD have indeed shown variable results. Briand and colleagues did not find a protective effect with the use of L acidophilus,[20] whereas other animal[21, 22] and human studies have shown a positive preventative effect of probiotics on TD.[11, 14] Similarly, in a recent meta-analysis, BAY 80-6946 nmr only 50% of the randomized clinical trials reported efficacy in the prevention of TD. Efficacy was reported with S boulardii, and L rhamnosus GG.[11, 13-15] Compared to placebo, S boulardii[13] decreased the incidence of TD from 39% to 29%–34% but success depended directly on the rigorous use of the preparation and only

1016 of the 3000 (34%) participants completed the study. Despite the high incidence of TD in our study, only seven subjects demonstrated carriage of a pathogen post-travel. AKSB pill microbiologic assessment showed that the capsules still contained viable organisms although there was a decline in the total CFU of probiotic Chlormezanone in approximately half of the pills returned. The medications were not required to be refrigerated but it is possible that travel to high temperature or humid climates may have affected the viability of the organisms. Limitations of this study include the lack of evidence of protocol adherence because the subjects were traveling and data were collected through self-reporting. Of those that reported compliance

only 58.2% were adherent to the protocol. There was no effective way to document reliability of the data entered into the daily diary. As less than half of the participants (43.8%) returned their pill bottles, post-travel pill count was not a reliable measure of compliance. Although there was a lack of protocol adherence, a trend toward benefit would have been expected toward reduction of TD incidence if the synbiotic had a beneficial effect. It is possible that the success of any TD prevention study will be fraught with such problems of compliance. Adherence to the study drugs (and real-life preventive medications) could potentially be increased with the use of individualized schedules, dosettes, and electronic-reminder devices including mobile smart phone-reminder utilization. These have been studied well in the HIV population for drug adherence.

The loxP recombination sites are only 34 bp in length and Cre wil

The loxP recombination sites are only 34 bp in length and Cre will recombine essentially any DNA substrates that contain these sites, with no requirements for the accessory proteins (Abremski & Hoess, 1985; Abremski et al., 1986). However, introducing loxP NVP-BKM120 cell line sites into pathogenic E. coli genomes using the common existing techniques has the disadvantage of being time-consuming (Murphy & Campellone, 2003; Lee et al., 2009). A

simple mutagenesis method without DNA cloning has been developed in E. coli. This method depends on the lambda Red gam, bet, and exo gene products, which encode an efficient homologs recombination system (Datsenko & Wanner, 2000; Yu et al., 2000). Using this method, modifications can be targeted precisely and can range from single base-pair deletions or insertions to the addition or deletion of sequences in the kilobase-pair range. Selection for the positive phenotype of the introduced

mutation has been difficult to achieve, making the use of a counter-selection approach very useful for the mutagenesis (Reyrat et al., 1998). A powerful counter-selection system for the introduction of mutations based on the wild-type rpsL gene responsible for streptomycin sensitivity has been described (Zhang et al., 2003; Rivero-Müller et al., 2007; Heermann et al., 2008). In E. coli, the rpsL gene encodes CYC202 molecular weight the S12 ribosomal protein of the 30S subunit, which is the target of streptomycin. Streptomycin inhibits protein, synthesis by binding near the interface of S12 ribosomal PAK6 protein, hence increasing the translational errors (Karimi & Ehrenberg, 1994, 1996). The prerequisite for this system to be effective is streptomycin-resistant strain. Resistance because of chromosomal mutations within rpsL is recessive in a merodiploid strain (Reyrat et al., 1998; Gill & Amyes, 2004). When both wild-type and mutant alleles of rpsL are expressed in the same strain, the strain

becomes sensitive to streptomycin (Reyrat et al., 1998). Here a method for site-directed mutagenesis of the APEC chromosome is described. Lambda Red recombination is used to introduce the loxP sites flanking the rpsL-neo marker into the APEC genome, and the Cre/lox system is used to remove the marker. Further, it is shown that rpsL counter-selection is applicable for introducing modifications into the APEC genome. Strains used and generated in this study are listed in Table 1. APEC1 strain was isolated from an infected chicken (Vandemaele et al., 2003). APEC1 strains containing plasmid pKD46 (Table 1) responsible for the homologs recombination (Datsenko & Wanner, 2000) and plasmid pSC101-BAD-Cre-tet (Anastassiadis et al., 2009) containing the cre gene responsible for the recombination of the loxP sites were incubated at 30 °C unless otherwise mentioned.

The considerable decline in the prevalence and severity of dental

The considerable decline in the prevalence and severity of dental caries following implementation of preventive strategies in the Scandinavian countries supports the application of a preventive approach[21-23]. One of the requirements for the success of oral health promotion strategies is the availability of knowledgeable and prevention-oriented health service practitioners who serve individuals and groups in need of dental care, including children[24]. Because of the great influence of such a workforce on community health, promoting social responsibility and ethical

Rapamycin practices of care givers has been emphasized by WHO as an objective for the year 2020[19]. The population of Nigeria is about 141 million, with an annual growth rate of 1.5%. The country is divided into six geopolitical zones, 36 states with a Federal Capital Territory, and 774 local government areas, with approximately 40.0% of the population living in urban areas. About 41.8% of the entire population

is 14 years and younger, making Nigeria one of the nations with a large population of young ones[25]. Providing preventive healthcare services for this teeming young population is therefore essential. This is more so that a number of authors have recommended greater focus on oral health promotion programmes for children based selleck screening library on the recently developed concepts of preventive Selleckchem Rucaparib oral care[26, 27]. For children, preventive oral health care will need to be implemented through both clinical care and community-based (school) intervention programmes. Such programmes certainly require a prevention-oriented dental workforce[28]. It is

therefore important to understand the preventive oral health practice of school educators and dental students as they are critical to the implementation of preventive dentistry. It is also equally important to identify how the preventive needs of children can be addressed by the dental workforce in training in the various dental schools in Nigeria. This study therefore aims to identify the determinants of caries prevention-oriented practice for children among final-year dental students in Nigeria. Possible determinant factors this study explored are age, gender, knowledge of caries prevention measures, and self-perceived competency in providing caries-preventive care for children. This report is part of a larger study. The methodology for the study was adopted from that used in a previous study[29]. The questionnaire was pilot-tested among five dental students who finished dental school within two months of piloting the questionnaire. Specific details on the questionnaire were adjusted based on outcomes of the discussions held with the students.


Raoult, Bleomycin personal communication). Intrathecal synthesis of B burgdorferi specific antibodies was negative. Culture of CSF on (Barbour-Stoenner-Kelly) BSKH medium was negative. ATBF was the first diagnosis suspected because of the travel destination, the association of tick-bite, and the presence of an inoculation eschar. Recently, in Ethiopia, ATBF was diagnosed in a French man after 1-month travel in this country.[11] Moreover, R africae has been detected in

12/118 Amblyomma lepidum and in 1/2 Amblyomma variegatum ticks collected on cattle in Ethiopia.[12] Radiculopathy was not described in association with this disease.[1] However, the evidence of subacute neuropathy of long-lasting duration had been reported for six patients following ATBF contracted during safari trips to southern Africa.[13] At the WHO Collaborative Center for Rickettsial Diseases and Arthropod-Borne Bacterial Diseases, all sera and skin biopsy samples negative for Rickettsiae from patients with tick-bite history and presence of inoculation eschar are tested for all bacteria transmitted by

ticks, including Coxiella burnetii, Bartonella, Anaplasma, Francisella tularensis, Borrelia, Diplorickettsia, Arsenophonus, Coxiella-like, and Spiroplasma. Using this strategy, only qPCR was positive for TBRF. Unfortunately, the species level identification was not determined because regular PCR remained negative probably because the borrelial DNA load detected using qPCR (known to be more sensitive than regular PCR) was low. Usually, the etiology of this website relapsing fever in Ethiopia is Borrelia recurrentis, the agent of louse-borne relapsing fever that is the most common cause of hospital admission, associated with high morbidity and mortality.[2] Soft ticks that are the main

known vectors of relapsing fever borrelioses do not attach firmly to the skin and cannot be “incompletely DNA ligase removed.” Here, the removed arthropod was probably not Ornithodoros tick, so, it can correspond to a hard tick. Recently, a new Borrelia sp. detected in A cohaerens, hard ticks collected from cattle in Ethiopia was described.[4] This new Borrelia sp. is distant from the groups of the recurrent fever and the Lyme disease that can explain in our case the discordance between the positive results by molecular tools: sequence 100% similarity with Borrelia sp. from relapsing fever group and positive serology for B burgdorferi. Neurological examination after 9 months of this patient showed that weakness and paresthesias disappeared but the persistence of the amyotrophy of the dorsal interossei of the hand resulting in a claw deformity. To the best of our knowledge, escharotic lesion has not been described in TBRF, but radiculopathy is common in tick-borne borreliosis.[14, 15] In patients returning from sub-Saharan Africa, TBRF should be included in differential diagnosis, especially in cases with neurological involvement, even without any systemic symptoms.

The first case series of THA for INFH in HIV-positive patients wa

The first case series of THA for INFH in HIV-positive patients was published in the early 21st Century and showed higher rates of subsequent infection and prosthesis complications than in the rest of the population. In 2003,

a study by Parvizi et al. was published of 21 HIV-infected patients who underwent total hip replacement surgery between 1979 and 1998; all the patients died within 10 years of follow-up, with 13 re-interventions and six cases of deep infection [22]. A very similar study, carried out by Christopher Lehman et al. in 29 HIV-positive patients who underwent surgery between 1983 BMS-354825 clinical trial and 1995, also showed that this poor prognosis was even worse in patients with IDU antecedents [21]. More recent studies in the HAART era, however, have revealed lower infection rates in HIV-positive

patients, but none of them compared the results with those for non-HIV-infected patients [28-33]. In 2005, Craig Mahoney et al. reported their results for a group of 40 HIV-infected patients in whom acute infection rates in the immediate postoperative stage had been lower than expected [28]. CHIR-99021 nmr In 2008, Haberman et al. reported a series of 55 cases of THA in HIV-positive individuals; postoperative complications appeared mainly in patients with a difficult social background [29]. Also in 2008, Bahebeck et al. carried out a prospective study in the hospital of Yaoundé, Cameroon, in HIV-positive patients enough with CD4 counts >500 cells/μl without HAART and those with CD4 counts <500 cells/μl with HAART who underwent any traumatological intervention. In this study, postsurgical infection rates in HIV-infected patients were similar to those seen in non-HIV-infected patients, but HIV-infected patients need extended antibiotic prophylaxis [30]. INFH is a relatively infrequent THA indication [34]. According to the literature, 70% of all cases of necrosis of the femoral head are bilateral

[35] and some authors even claim that these are always bilateral, although not always symptomatic. In our study, 61% of patients in the HIV-positive group and 55% of patients in the control group had been diagnosed with bilateral necrosis. We did, however, find differences between the two groups in the involvement of other joints. HIV-infected patients had been more frequently diagnosed with osteonecrosis in areas other than the hip, such as the humeral head, femoral condyle or tibia and talus. Dudkiewicz et al. established that the aetiology of INFH did not affect initial THA results [36]. However, in cases in which INFH was induced by corticoid treatment, the longevity of the implant appeared more limited. In our study we found that there were no significant differences in the delay in INFH diagnosis, time spent in surgery, duration of hospitalitzation or the functional outcome of arthroplasty.

Travelers to developing countries may be exposed to various infec

Travelers to developing countries may be exposed to various infectious diseases, the risks being NVP-BKM120 ic50 widespread throughout tropical and subtropical areas. This is a particular concern for travel health professionals in Japan as the number of Japanese travelers is growing, with over 17 million overseas travelers in 2007 and 2008, a substantial proportion of which travel to developing countries. Strategies to reduce travel-acquired

infections include good pre-travel preparation, obtaining up-to-date information on the risks in the destination, advice on behavior modification to avoid exposure to pathogens while traveling, and the use of prophylactic agents (ie, chemoprophylaxis and vaccinations) based on a thorough risk assessment. Immunizations, in particular, provide a potent, long-acting means of protecting against certain pathogens, and while they are routinely Erastin solubility dmso recommended for travelers in many Western countries, there is concern that Japanese travelers are poorly protected against many vaccine-preventable infections. Several studies have investigated the knowledge, attitudes, and practices (KAP) of travelers regarding their preparation for travel, their use of malaria prevention measures and vaccination coverage, using a standardized questionnaire

developed by the European Travel Health Advisory Board (ETHAB). These studies were conducted at international airports in various regions of the world, and the results were published consecutively.1–4 Using the same questionnaire, we conducted a similar study on malaria prevention among Japanese travelers which demonstrated suboptimal use of malaria prevention measures.5 We recently conducted RG7420 purchase a further questionnaire-based study of Japanese travelers to examine the measures taken to reduce their risk of acquiring an infectious disease and investigate immunization

uptake. The questionnaire, devised by ETHAB and modified following a pilot study,6 was kindly provided by Professor R. Steffen of the University of Zurich. The questionnaire was translated into Japanese, with minor adjustments to make it applicable to Japanese travelers. In total, there were 19 items covering two categories: one on general travel health issues and the other on vaccination. The vaccinations covered were hepatitis A, hepatitis B, cholera, yellow fever, typhoid fever, tetanus, polio, rabies, meningitis, tuberculosis, diphtheria, and influenza. Between April 2007 and May 2008, tour group operators distributed questionnaires to travelers at the end of their overseas tour. Travelers were asked to complete the questionnaires on site and return them to the tour operator. In addition, questionnaires were mailed to individual travelers after returning to Japan from the travel agents that arranged the overseas trip. The questionnaires were anonymized.

To monitor growth, 200 μL of culture was sampled in triplicate an

To monitor growth, 200 μL of culture was sampled in triplicate and 10-fold serial dilutions were made in phosphate-buffered saline (PBS) and 50 μL of the dilutions were spread on TSA plates to determine the CFUs after incubation for 2–3 days at 37 °C under 5% CO2. The J774A.1 murine macrophage-like cells were grown in Dulbecco’s modified Eagle’s medium (DMEM) supplemented with 10% heat-inactivated fetal calf serum in a humidified 5% CO2 atmosphere at 37 °C. About 1 × 106 Selleck Fulvestrant cells were seeded

per well in a 24-well plate (Corning Incorporated). After 18 h of the incubation, the cells were infected with a multiplicity of infection of 100 : 1 (100 Brucella per macrophage). After 1 h of incubation (which was considered as the 0-h time point for all the experiments), the cells were washed three times with DMEM media containing 50 μg mL−1 gentamicin to wash off all the extracellular bacteria. Fresh DMEM containing 50 μg mL−1 gentamicin and 10% fetal bovine serum (FBS) was added for further incubation. As needed, 30 μM deferoxamine mesylate (DFA) was added to the culture media 48 h before infecting the J774A.1 cells to allow the chemical binding between DFA and iron. At 0, 24 and 48 h postinfection, macrophages were lysed using 1 mL of 0.1% TritonX-100, and lysates were collected and serial dilutions prepared in PBS and spread

on TSA plates to determine the CFUs of Brucella. All statistical analyses were performed using the Student two-tailed t-test using Microsoft excel. P-values ≤0.005 were considered significant (*). Deletion of 497 base pairs from the entF gene (BAN1 strain) and complementation ABT-737 cost by pNSGro∷entF plasmid (BAN2 strain) were confirmed by PCR using the entF forward and reverse primers (data not shown).

Further, to confirm the expression of entF gene in the complemented strain, RT-PCR (Fig. 2) revealed that the entF gene was expressed in the BAN2 strain, but not in the ΔentF mutant Mannose-binding protein-associated serine protease (BAN1). Intergenic expression of entB-A or dhbB-A, shown (Bellaire et al., 2003b) to occur under iron-limiting conditions by B. abortus 2308, was used as the positive control. Under iron limitation, the wild-type strain did not reach the same cell density and had a slower growth rate compared with growth in IMM supplemented with iron (Fig. 3). This confirms the importance of iron for the growth of B. abortus 2308 as shown by others (Evenson & Gerhardt, 1955; Parent et al., 2002; Wandersman & Delepelaire, 2004). The ΔentF strain (BAN1) grew even more slowly compared with the wild-type strain in IMM, suggesting the importance of entF gene with respect to growth. The addition of 50 μM FeCl3 restored the growth of both wild-type and mutant strains, suggesting that iron was the only limiting factor in the medium. If a particular mutated gene affects the growth of a bacterium under iron-limiting conditions, the mutated gene might be involved in acquisition, transport or metabolism within the iron pathway.