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Fulltext Antibiotic Susceptibility Patterns, Biofilm Formation and esp Gene among Clinical Enterococci: Is There Any Association?

Weng PL, Ramli R, Hamat RA

Int J Environ Res Public Health, 2019 09 17;16(18).
PMID: 31533204 DOI: 10.3390/ijerph16183439

Enterococci are commonly found in humans, animals and environments. Their highly adaptive mechanisms are related to several virulent determinants and their ability to resist antibiotics. Data on the relationship between the esp gene, biofilm formation and antibiotic susceptibility profiles may differ between countries. This cross-sectional study was conducted to determine the proportion of esp gene and biofilm formation among Enterococcus faecalis and Enterococcus faecium clinical isolates. We also investigated the possible association between the esp gene with antibiotic susceptibility patterns and biofilm formation. The isolates were collected from clinical samples and identified using biochemical tests and 16SRNA. Antibiotic susceptibility patterns and a biofilm assay were conducted according to the established guidelines. Molecular detection by PCR was used to identify the esp gene using established primers. In total, 52 and 28 of E. faecalis and E. faecium were identified, respectively. E. faecium exhibited higher resistance rates compared to E. faecalis as follows: piperacillin/tazobactam (100% versus 1.9%), ampicillin (92.8% versus 1.9%), high-level gentamicin resistance (HLGR) (89.3% versus 25.0%) and penicillin (82.1% versus 7.7%). E. faecium produced more biofilms than E. faecalis (59.3% versus 49.0%). E. faecium acquired the esp gene more frequently than E. faecalis (78.6% versus 46.2%). Interestingly, the associations between ampicillin and tazobactam/piperacillin resistance with the esp gene were statistically significant (X2 = 4.581, p = 0.027; and X2 = 6.276, p = 0.012, respectively). Our results demonstrate that E. faecium exhibits high rates of antimicrobial resistance, esp gene acquisition and biofilm formation. These peculiar traits of E. faecium may have implications for the management of enterococcal infections in hospitals. Thus, concerted efforts by all parties in establishing appropriate treatment and effective control measures are warranted in future.

Matched MeSH terms: Microbial Sensitivity Tests
Antibacterial and antioxidant activity of naphthofuranquinones from the twigs of tropical mangrove Avicennia officinalis

Assaw S, Mohd Amir MIH, Khaw TT, Bakar K, Mohd Radzi SA, Mazlan NW

Nat Prod Res, 2020 Aug;34(16):2403-2406.
PMID: 30600710 DOI: 10.1080/14786419.2018.1538220

Mangrove plants are endowed with various biologically active compounds which have potent antibacterial and antioxidant properties. In present study, a bioactivity-guided fractionation for antibacterial and antioxidant active metabolites from the twigs of Avicennia officinalis collected from Kuala Selangor Nature Park, Selangor, Malaysia gave 13 major fractions. The antibacterial activity of A. officinalis fractions using well-diffusion showed strong selectivity on the Gram-positive bacteria (Staphylococcus epidermidis, S. aureus and Bacillus subtilis) with minimum inhibition concentration (MIC) values of 0.156-5.00 mg/mL. However, no antibacterial activities were observed on the Gram-negative bacteria (Vibrio cholera, Enterobacter cloacae and Escherichia coli). The active antibacterial fractions were further isolated using several chromatographic techniques to give two naphthofuranquinones, namely, avicenol C (1) and stenocarpoquinone B (2). Meanwhile, the antioxidant activity of A. officinalis fractions were evaluated using DPPH radical scavenging assay exhibited low antioxidant activities. Molecular structure of the naphthofuranquinones was elucidated using 1 D and 2 D NMR spectroscopy.

Matched MeSH terms: Microbial Sensitivity Tests
Synthesis of novel quinoline-based thiadiazole, evaluation of their antileishmanial potential and molecular docking studies

Almandil NB, Taha M, Rahim F, Wadood A, Imran S, Alqahtani MA, et al.

Bioorg Chem, 2019 04;85:109-116.
PMID: 30605884 DOI: 10.1016/j.bioorg.2018.12.025

New series of quinoline-based thiadiazole analogs (1-20) were synthesized, characterized by EI-MS, 1H NMR and 13C NMR. All synthesized compounds were subjected to their antileishmanial potential. Sixteen analogs 1-10, 12, 13, 16, 17, 18 and 19 with IC50 values in the range of 0.04 ± 0.01 to 5.60 ± 0.21 µM showed tremendously potent inhibition as compared to the standard pentamidine with IC50 value 7.02 ± 0.09 µM. Analogs 11, 14, 15 and 20 with IC50 8.20 ± 0.35, 9.20 ± 0.40, 7.20 ± 0.20 and 9.60 ± 0.40 µM respectively showed good inhibition when compared with the standard. Structure-activity relationships have been also established for all compounds. Molecular docking studies were performed to determine the binding interaction of the compounds with the active site target.

Matched MeSH terms: Microbial Sensitivity Tests
Fulltext Phyto-Mediated Photo Catalysed Green Synthesis of Silver Nanoparticles Using Durio Zibethinus Seed Extract: Antimicrobial and Cytotoxic Activity and Photocatalytic Applications

Sumitha S, Vasanthi S, Shalini S, Chinni SV, Gopinath SCB, Anbu P, et al.

Molecules, 2018 Dec 13;23(12).
PMID: 30551671 DOI: 10.3390/molecules23123311

In the present study, we have developed a green approach for the synthesis of silver nanoparticles (DSAgNPs) using aqueous extract of Durio zibethinus seed and determined its antibacterial, photocatalytic and cytotoxic effects. Surface plasmon resonance confirmed the formation of DSAgNPs with a maximum absorbance (λmax) of 420 nm. SEM and TEM images revealed DSAgNPs were spherical and rod shaped, with a size range of 20 nm and 75 nm. The zeta potential was found to be -15.41 mV. XRD and EDX analyses confirmed the nature and presence of Ag and AgCl. DSAgNPs showed considerable antibacterial activity, exhibited better cytotoxicity against brine shrimp, and shown better photocatalytic activity against methylene blue. Based on the present research work, it can be concluded that DSAgNPs could be used in the field of water treatment, pharmaceuticals, biomedicine, biosensor and nanotechnology in near future.

Matched MeSH terms: Microbial Sensitivity Tests
Antibiotic resistance, putative virulence factors and curli fimbrination among Cronobacter species

Odeyemi OA, Abdullah Sani N

Microb Pathog, 2019 Nov;136:103665.
PMID: 31404630 DOI: 10.1016/j.micpath.2019.103665

This study aimed to investigate antibiotic resistance and putative virulence factors among Cronobacter sakazakii isolated from powdered infant formula and other sources. The following 9 cultures (CR1-9) were collected from our culture collection: C. sakazakii and 3 Cronobacter species: C. sakazakii ATCC® 29544™, C. muytjensii ATCC® 51329™, C. turicensis E866 were used in this study. Isolates were subjected to antibiotic susceptibility and the following virulence factors (protease, DNase, haemolysin, gelatinase, motility and biofilm formation) using phenotypic methods. All the bacteria were able to form biofilm on agar at 37 °C and were resistant to ampicillin, erythromycin, fosfomycin and sulphamethoxazole. It was observed from this study that tested strains formed weak and strong biofilm with violet dry and rough (rdar), brown dry and rough (bdar), red mucoid and smooth (rmas) colony morphotypes on Congo red agar. Rdar expresses curli and fimbriae, while bdar expresses curli. Both biofilm colony morphotypes are commonly found in Enterobacteriaceae including Salmonella species. This study also reveals a new colony morphotypes in Cronobacter species. Conclusively, there was correlation between putative virulence factors and antibiotic resistance among the tested bacteria. Further study on virulence and antibiotic resistance genes is hereby encouraged.

Matched MeSH terms: Microbial Sensitivity Tests
Carnosine exhibits significant antiviral activity against Dengue and Zika virus

Rothan HA, Abdulrahman AY, Khazali AS, Nor Rashid N, Chong TT, Yusof R

J. Pept. Sci., 2019 Aug;25(8):e3196.
PMID: 31290226 DOI: 10.1002/psc.3196

Dengue virus (DENV) and Zika virus (ZIKV) are flaviviruses transmitted to humans by their common vector, Aedes mosquitoes. DENV infection represents one of the most widely spread mosquito-borne diseases whereas ZIKV infection occasionally re-emerged in the past causing outbreaks. Although there have been considerable advances in understanding the pathophysiology of these viruses, no effective vaccines or antiviral drugs are currently available. In this study, we evaluated the antiviral activity of carnosine, an endogenous dipeptide (β-alanyl-l-histidine), against DENV serotype 2 (DENV2) and ZIKV infection in human liver cells (Huh7). Computational studies were performed to predict the potential interactions between carnosine and viral proteins. Biochemical and cell-based assays were performed to validate the computational results. Mode-of-inhibition, plaque reduction, and immunostaining assays were performed to determine the antiviral activity of carnosine. Exogenous carnosine showed minimal cytotoxicity in Huh7 cells and rescued the viability of infected cells with EC50 values of 52.3 and 59.5 μM for DENV2 and ZIKV infection, respectively. Based on the mode-of-inhibition assays, carnosine inhibited DENV2 mainly by inhibiting viral genome replication and interfering with virus entry. Carnosine antiviral activity was verified with immunostaining assay where carnosine treatment diminished viral fluorescence signal. In conclusion, carnosine exhibited significant inhibitory effects against DENV2 and ZIKV replication in human liver cells and could be utilized as a lead peptide for the development of effective and safe antiviral agents against DENV and ZIKV.

Matched MeSH terms: Microbial Sensitivity Tests
Investigation of the antibacterial activity of Ag-NPs conjugated with a specific antibody against Staphylococcus aureus after photoactivation

Al-Sharqi A, Apun K, Vincent M, Kanakaraju D, Bilung LM, Sum MSH

J Appl Microbiol, 2020 Jan;128(1):102-115.
PMID: 31596989 DOI: 10.1111/jam.14471

AIM: This work reports a new method for the use of lasers for the selective killing of bacteria targeted using light-absorbing Silver nanoparticles (Ag-NPs) conjugated with a specific antibody against the Gram-positive bacterium Staphylococcus aureus (S. aureus).
METHODS AND RESULTS: Ag-NPs were synthesized using a chemical reduction method and characterized with respect to their surface plasmon resonance, surface morphology via transmission electron microscopy (TEM) and dynamic light scattering (DLS). The bacterial surface was targeted using 20 nm Ag-NPs conjugated with an anti-protein A antibody. Labelled bacteria were irradiated with blue visible laser at 2·04 W/cm2 . The antibacterial activity of functionalized Ag-NPs was investigated by fluorescence microscopy after irradiation, and morphological changes in S. aureus after laser treatment were assessed using scanning electron microscopy (SEM). The laser-irradiated, functionalized Ag-NPs exhibited significant bactericidal activity, and laser-induced bacterial damage was observed after 10 min of laser irradiation against S. aureus. The fluorescence microscopic analysis results supported that bacterial cell death occurred in the presence of the functionalized Ag-NPs.
CONCLUSIONS: The results of this study suggest that a novel method for the preparation of functionalized nanoparticles has potential as a potent antibacterial agent for the selective killing of resistant disease-causing bacteria.
SIGNIFICANCE AND IMPACT OF THE STUDY: This study shows that Ag-NPs functionalized with a specific antibody, could be used in combination with laser radiation as a novel treatment to target resistant bacterial and fungal pathogens with minimal impact on normal microflora.

Matched MeSH terms: Microbial Sensitivity Tests
Antifungal garcinia acid esters from the fruits of Garcinia atroviridis

Mackeen MM, Ali AM, Lajis NH, Kawazu K, Kikuzaki H, Nakatani N

Z Naturforsch C J Biosci, 2002 6 18;57(3-4):291-5.
PMID: 12064729

Two new garcinia acid derivatives, 2-(butoxycarbonylmethyl)-3-butoxycarbonyl-2-hydroxy-3-propanolide and 1',1"-dibutyl methyl hydroxycitrate, were isolated from the fruits of Garcinia atroviridis guided by TLC bioautography against the fungus Cladosporium herbarum. The structures of these compounds were established by spectral analysis. The former compound represents a unique beta-lactone structure and the latter compound is most likely an artefact of garcinia acid (= hydroxycitric acid). Both compounds showed selective antifungal activity comparable to that of cycloheximide (MID: 0.5 microg/spot) only against C herbarum at the MIDs of 0.4 and 0.8 microg/spot but were inactive against bacteria (Bacillus subtilis, methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli), other fungi (Alternaria sp., Fusarium moniliforme and Aspergillus ochraceous) including the yeast Candida albicans.

Matched MeSH terms: Microbial Sensitivity Tests
Identification of a novel SHV-β-lactamase variant (SHV-144) in a Malaysian multidrug-resistant Klebsiella pneumoniae isolate

Al-Marzooq F, Yusof MY, Tay ST

Jpn J Infect Dis, 2013;66(6):555-7.
PMID: 24270152
Matched MeSH terms: Microbial Sensitivity Tests
Fulltext Molecular characterization of multi-drug resistant Escherichia coli isolates from tropical environments in Southeast Asia

Hara H, Yusaimi YA, Zulkeflle SNM, Sugiura N, Iwamoto K, Goto M, et al.

J Gen Appl Microbiol, 2019 Jan 24;64(6):284-292.
PMID: 29877296 DOI: 10.2323/jgam.2018.02.003

The emergence of antibiotic resistance among multidrug-resistant (MDR) microbes is of growing concern, and threatens public health globally. A total of 129 Escherichia coli isolates were recovered from lowland aqueous environments near hospitals and medical service centers in the vicinity of Kuala Lumpur, Malaysia. Among the eleven antibacterial agents tested, the isolates were highly resistant to trimethoprim-sulfamethoxazole (83.7%) and nalidixic acid (71.3%) and moderately resistant to ampicillin and chloramphenicol (66.7%), tetracycline (65.1%), fosfomycin (57.4%), cefotaxime (57.4%), and ciprofloxacin (57.4%), while low resistance levels were found with aminoglycosides (kanamycin, 22.5%; gentamicin, 21.7%). The presence of relevant resistance determinants was evaluated, and the genotypic resistance determinants were as follows: sulfonamides (sulI, sulII, and sulIII), trimethoprim (dfrA1 and dfrA5), quinolones (qnrS), β-lactams (ampC and blaCTX-M), chloramphenicol (cmlA1 and cat2), tetracycline (tetA and tetM), fosfomycin (fosA and fosA3), and aminoglycosides (aphA1 and aacC2). Our data suggest that multidrug-resistant E. coli strains are ubiquitous in the aquatic systems of tropical countries and indicate that hospital wastewater may contribute to this phenomenon.

Matched MeSH terms: Microbial Sensitivity Tests
The synergistic effects of cinnamon essential oil and nano TiO2 on antimicrobial and functional properties of sago starch films

Arezoo E, Mohammadreza E, Maryam M, Abdorreza MN

Int J Biol Macromol, 2020 Aug 15;157:743-751.
PMID: 31805325 DOI: 10.1016/j.ijbiomac.2019.11.244

This study describes a sago starch-based film by incorporation of cinnamon essential oil (CEO) and nano titanium dioxide (TiO2-N). Different concentrations (i.e., 0%, 1%, 3%, and 5%, w/w) of TiO2-N and CEO (i.e., 0%, 1%, 2%, and 3%, v/w) were incorporated into sago starch film, and the physicochemical, barrier, mechanical, and antimicrobial properties of the bionanocomposite films were estimated. Incorporation of CEO into the sago starch matrix increased oxygen and water vapor permeability of starch films while increasing TiO2-N concentration decreased barrier properties. Moisture content also decreased from 12.96% to 8.04%, solubility in water decreased from 25% to 13.7%, and the mechanical properties of sago starch films improved. Sago starch bionanocomposite films showed excellent antimicrobial activity against Escherichia coli, Salmonella typhimurium, and Staphylococcus aureus. Results also showed that incorporation of TiO2-N and CEO had synergistic effects on functional properties of sago starch films. In summary, sago starch films incorporated with both TiO2-N and CEO shows potential application for active packaging in food industries such as fresh pistachio packaging.

Matched MeSH terms: Microbial Sensitivity Tests
Antagonistic effects of Streptomyces violaceusniger strain G10 on Fusarium oxysporum f.sp. cubense race 4: indirect evidence for the role of antibiosis in the antagonistic process

Getha K, Vikineswary S

J Ind Microbiol Biotechnol, 2002 Jun;28(6):303-10.
PMID: 12032802

Fusarium oxysporum f.sp. cubense is the causal pathogen of wilt disease of banana. A cost-effective measure of control for this disease is still not available. Streptomyces violaceusniger strain G10 acts as an antifungal agent antagonistic towards many different phytopathogenic fungi, including different pathogenic races of the Fusarium wilt pathogen. In an attempt to understand the mode of action of this antagonist in nature, the interaction between S. violaceusniger strain G10 and F. oxysporum f.sp. cubense was first studied by paired incubation on agar plates. Evidence for the in vitro antibiosis of strain G10 was demonstrated by inhibition zones in the "cross-plug" assay plates. Microscopic observations showed lysis of hyphal ends in the inhibited fungal colonies. Culture of strain G10 in liquid media produces antifungal metabolites, which showed in vitro antagonistic effects against F. oxysporum f.sp. cubense such as swelling, distortion and excessive branching of hyphae, and inhibition of spore germination. An indirect method was used to show that antibiosis is one of the mechanisms of antagonism by which strain G10 acts against F. oxysporun f.sp. cubense in soil. This study suggests the potential of developing strain G10 for the biological control of Fusarium wilt disease of banana.

Matched MeSH terms: Microbial Sensitivity Tests
D-glucosamine chitosan base molecule-assisted synthesis of different shape and sized silver nanoparticles by a single pot method: A greener approach for sensor and microbial applications

Ranjani B, Pandian K, Kumar GA, Gopinath SCB

Int J Biol Macromol, 2019 Jul 15;133:1280-1287.
PMID: 31051204 DOI: 10.1016/j.ijbiomac.2019.04.196

Silver nanoparticle was synthesized using D-glucosamine chitosan base as green reducing agent at elevated temperature in alkaline pH ranges. The excess of D-glucosamine chitosan base was used as it is both stabilizing and reducing agent at different pHs, regulates the shape and size of the silver nanoparticles. The progressive growth of silver nanoparticles was monitored by UV-Visible spectral studies. A sharp peak at 420 nm indicates the formation of spherical silver nanoparticles. The size and shape of silver nanoparticles were observed from Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) methods. The anisotropically grown nanoparticles were used as probe for Surface Enhanced Raman Studies (SERS) using ATP (4-aminothiophenol) as a model system. The catalytic behavior of silver nanoparticles was exploited for 4-nitrophenol reduction and observed that the reduction reaction follows pseudo first order kinetics with a rate constant 0.65 min. The antibacterial activity of silver nanoparticles was also tested for both gram-positive and -negative microorganisms, in which higher zone of inhibition was observed for gram negative microorganism.

Matched MeSH terms: Microbial Sensitivity Tests
Oxidative stress resistance and fitness-compensatory response in vancomycin-intermediate Staphylococcus aureus (VISA)

Tan XE, Neoh HM, Cui L, Hiramatsu K, Jamal R

Can J Microbiol, 2019 Aug;65(8):623-628.
PMID: 31063703 DOI: 10.1139/cjm-2019-0048

In this study, vancomycin-intermediate Staphylococcus aureus (VISA) cells carrying vraS and (or) graR mutations were shown to be more resistant to oxidative stress. Caenorhabditis elegans infected with these strains in turn demonstrated lower survival. Altered regulation in oxidative stress response and virulence appear to be physiological adaptations associated with the VISA phenotype in the Mu50 lineage.

Matched MeSH terms: Microbial Sensitivity Tests
Changes in serotype distribution and antimicrobial resistance of Streptococcus pneumoniae isolates from adult patients in Asia: Emergence of drug-resistant non-vaccine serotypes

Kim SH, Chung DR, Song JH, Baek JY, Thamlikitkul V, Wang H, et al.

Vaccine, 2020 08 27;38(38):6065-6073.
PMID: 31590932 DOI: 10.1016/j.vaccine.2019.09.065

This study was performed to investigate the serotype distribution and antimicrobial susceptibility of Streptococcus pneumoniae in Asian countries. A prospective surveillance study on S. pneumoniae collected from adult patients (≥50 years old) with invasive pneumococcal disease or community-acquired pneumonia was performed at 66 hospitals in Asian countries (Korea, China, Malaysia, Singapore, the Philippines, and Thailand) in 2012-2017. Serotyping and antimicrobial susceptibility tests of 850 pneumococcal isolates were performed. The proportions of isolates with serotypes covered by 13-valent pneumococcal conjugate vaccine (PCV13) were 37.0% in Korea, 53.4% in China, 77.2% in Malaysia, 35.9% in the Philippines, 68.7% in Singapore, and 60.2% in Thailand. Major serotypes were 19F (10.4%), 19A (10.1%), and 3 (8.5%) in 2012-2017, with different serotype distributions in each country. Macrolide resistance in pneumococci was high (66.8%) and prevalence of multidrug resistance (MDR) also remained high (50.8%). MDR non-PCV13 serotypes such as 11A, 15A, 35B, and 23A have emerged in Asian countries. This study showed the persistent prevalence of 19F and 19A with a noteworthy increase of certain non-PCV13 serotypes in Asian countries. High prevalence of macrolide resistance and MDR was also found in pneumococcal isolates. These data emphasize the need for continued surveillance of pneumococcal epidemiology in Asia in the post-pneumococcal vaccine era.

Matched MeSH terms: Microbial Sensitivity Tests
Fulltext Distribution, antifungal susceptibility pattern and intra-Candida albicans species complex prevalence of Candida africana: A systematic review and meta-analysis

Gharehbolagh SA, Fallah B, Izadi A, Ardestani ZS, Malekifar P, M Borman A, et al.

PLoS One, 2020;15(8):e0237046.
PMID: 32817677 DOI: 10.1371/journal.pone.0237046

Candida africana is a pathogenic species within the Candida albicans species complex. Due to the limited knowledge concerning its prevalence and antifungal susceptibility profiles, a comprehensive study is overdue. Accordingly, we performed a search of the electronic databases for literature published in the English language between 1 January 2001 and 21 March 2020. Citations were screened, relevant articles were identified, and data were extracted to determine overall intra-C. albicans complex prevalence, geographical distribution, and antifungal susceptibility profiles for C. africana. From a total of 366 articles, 41 were eligible for inclusion in this study. Our results showed that C. africana has a worldwide distribution. The pooled intra-C. albicans complex prevalence of C. africana was 1.67% (95% CI 0.98-2.49). Prevalence data were available for 11 countries from 4 continents. Iran (3.02%, 95%CI 1.51-4.92) and Honduras (3.03%, 95% CI 0.83-10.39) had the highest values and Malaysia (0%) had the lowest prevalence. Vaginal specimens were the most common source of C. africana (92.81%; 155 out of 167 isolates with available data). However, this species has also been isolated from cases of balanitis, from patients with oral lesions, and from respiratory, urine, and cutaneous samples. Data concerning the susceptibility of C. africana to 16 antifungal drugs were available in the literature. Generally, the minimum inhibitory concentrations of antifungal drugs against this species were low. In conclusion, C. africana demonstrates geographical variation in prevalence and high susceptibility to antifungal drugs. However, due to the relative scarcity of existing data concerning this species, further studies will be required to establish more firm conclusions.

Matched MeSH terms: Microbial Sensitivity Tests
Fulltext Characterization of multiple-antimicrobial-resistant Salmonella enterica Subsp. enterica isolated from indigenous vegetables and poultry in Malaysia

Yoke-Kqueen C, Learn-Han L, Noorzaleha AS, Son R, Sabrina S, Jiun-Horng S, et al.

Lett Appl Microbiol, 2008 Mar;46(3):318-24.
PMID: 18179445 DOI: 10.1111/j.1472-765X.2007.02311.x

The aims of this communication were to study characterization of serogroups among Salmonella isolates and the relationship of antimicrobial resistance to serogroups. Multiple antimicrobial resistance (MAR) was performed on 189 Salmonella enterica isolates associated with 38 different serovars that were recovered from poultry and four types of indigenous vegetables.

Matched MeSH terms: Microbial Sensitivity Tests
Gut bacteria of cockroaches are a potential source of antibacterial compound(s)

Akbar N, Siddiqui R, Iqbal M, Sagathevan K, Khan NA

Lett Appl Microbiol, 2018 May;66(5):416-426.
PMID: 29457249 DOI: 10.1111/lam.12867

Here, we hypothesized that the microbial gut flora of animals/pests living in polluted environments, produce substances to thwart bacterial infections. The overall aim of this study was to source microbes inhabiting unusual environmental niches for potential antimicrobial activity. Two cockroach species, Gromphadorhina portentosa (Madagascar) and Blaptica dubia (Dubia) were selected. The gut bacteria from these species were isolated and grown in RPMI 1640 and conditioned media were prepared. Conditioned media were tested against a panel of Gram-positive (Methicillin-resistant Staphylococcus aureus, Streptococcus pyogenes, Bacillus cereus) and Gram-negative (Escherichia coli K1, Salmonella enterica, Serratia marcescens, Pseudomonas aeruginosa, Klebsiella pneumoniae) bacteria, as well as the protist pathogen, Acanthamoeba castellanii. The results revealed that the gut bacteria of cockroaches produce active molecule(s) with potent antibacterial properties, as well as exhibit antiamoebic effects. However, heat-inactivation at 95°C for 10 min had no effect on conditioned media-mediated antibacterial and antiamoebic properties. These results suggest that bacteria from novel sources i.e. from the cockroach's gut produce molecules with bactericidal as well as amoebicidal properties that can ultimately lead to the development of therapeutic drugs.
SIGNIFICANCE AND IMPACT OF THE STUDY: The bacteria isolated from unusual dwellings such as the cockroaches' gut are a useful source of antibacterial and antiamoebal molecules. These are remarkable findings that will open several avenues in our search for novel antimicrobials from unique sources. Furthermore studies will lead to the identification of molecules to develop future antibacterials from insects.

Matched MeSH terms: Microbial Sensitivity Tests
Proteinase, phospholipase, biofilm forming abilities and antifungal susceptibilities of Malaysian Candida isolates from blood cultures

Tay ST, Abidin IA, Hassan H, Ng KP

Med Mycol, 2011 Jul;49(5):556-60.
PMID: 21254967 DOI: 10.3109/13693786.2010.551424

This study was conducted to determine the proteinase, phospholipase, and biofilm forming abilities of Candida isolates in blood cultures of specimens from patients at the University Malaya Medical Center, Kuala Lumpur, Malaysia. Proteinase and phospholipase activities were detected in 93.7% and 73.3%, respectively, of 15 Candida albicans isolates. Amongst the 26 non-C. albicans Candida isolates, proteinase and phospholipase activities were detected in 88.5% and 7.7% of the isolates, respectively. There was no significant difference in the expression levels of proteinase amongst the Candida isolates studied (P = 0.272), but the phospholipase activity of C. albicans was significantly higher than that of the non-C. albicans Candida isolates (P = 0.003). There was no significant difference in the biofilm forming abilities of C. albicans and non-C. albicans Candida isolates on the polystyrene microtiter wells (P = 0.379). In addition, the findings of this study demonstrate increased resistance of Candida isolates in biofilms to amphotericin and fluconazole, as compared to their planktonic counterparts.

Matched MeSH terms: Microbial Sensitivity Tests
Isolates of the emerging pathogen Candida auris present in the UK have several geographic origins

Borman AM, Szekely A, Johnson EM

Med Mycol, 2017 Jul 01;55(5):563-567.
PMID: 28204557 DOI: 10.1093/mmy/myw147

Candida auris has recently emerged as a serious nosocomial health risk, with widespread outbreaks in numerous hospitals worldwide and the existence of geographic region-specific discrete clonal lineages. Here we have compared the rDNA sequences of 24 isolates of Candida auris from 14 different hospital centers in the United Kingdom with those of strains from different international origins present in the public sequence databases. Here we show that UK isolates of C. auris fall into three well-supported clades corresponding to lineages that have previously been reported from India, Malaysia and Kuwait, Japan and Korea, and South Africa, respectively.

Matched MeSH terms: Microbial Sensitivity Tests

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