Authors:Navid Sahebekhtiari, Zahra Nochi, Mohammad Eslampour, Hossein Dabiri, Mehdi Bolfion, Morovat Taherikalani, Babak Khoramian, Mohammad Zali, and Mohammad Emaneini
Staphylococcus aureus is considered one of the most important food borne pathogens.A total of 111 isolates of S. aureus were cultured from raw milk samples during January 2009 to June 2009 from Tehran and Mashhad. The coagulase gene polymorphism and the prevalence of classical enterotoxin genes of S. aureus strains were determined by PCR-RFLP (restriction fragment length polymorphism) and Multiplex-PCR. Disk diffusion method was used to determine the susceptibility of isolates to antimicrobial agents as instructed by Clinical and Laboratory Standards Institute.Sixty-seven % of the isolates harboured one or more enterotoxin genes. The most prevalent gene was sec, found in 59 % of the isolates. Approximately 8% of the isolates were positive for sea, seb and sed genes. Only one isolate had see gene. The rate of coexistence of enterotoxin genes was 14%. All S. aureus isolates were susceptible to ciprofloxacin, gentamicin, imipenem, minocycline, oxacillin and vancomycin. They were resistant to ampicillin (64%), penicillin (56%), clindamycin (22%), tetracycline (22%), doxycycline (19%), teicoplanin (13%), rifampin (2%) and trimethoprim-sulfamethoxazole (2%). On the basis of coagulase gene analysis of 111 S. aureus isolates, the PCR products of 56 isolates were digested with Alu I that produced three distinct patterns.These data indicate the high prevalence of enterotoxigenic S. aureus in raw bovine milk in Tehran and Mashhad, and highlight the importance of proper quality control of dairy products for public health.
Authors:Mohammad Taghi Haghi-Ashtiani, Setareh Mamishi, Nasrin Shayanfar, Masoud Mohammadpour, Bahareh Yaghmaei, Mina Abedini, Narges Farahani, and Nima Rezaei
Bacterial meningitis continues to be associated with high morbidity and mortality rate worldwide, especially in the pediatric age group. This study was performed to identify the microbial etiologies of meningitis among 31 children, who were admitted in the Emergency Ward of a referral pediatric hospital in Iran. Culture identification showed that Streptococcus pneumoniae (12 subjects), Haemophilus influenzae (11 subjects) were the most common bacteria, followed by Escherichia coli (7 cases) and Neisseria meningitidis (only one case). Antibiotic susceptibility tests revealed that vancomycin had the best effect on S. pneumoniae in comparison with other antibiotics, whereas H. influenzae and E. coli were more susceptible to ceftriaxone, ceftazidime, and ceftizoxime than other antibiotics. In conclusion, despite the advances in antibiotic therapy and vaccine development, bacterial meningitis still is a health problem. S. pneumoniae, H. influenzae, and N. meningitidis are the main sources of bacterial meningitis, but other organisms such as E. coli should also be suspected, when a case is admitted to a referral pediatric hospital.
Graft copolymers of 2-(dimethylamino)ethylmethacrylate (DMAEMA) and acrylic acid (AAc) onto polypropylene films were investigated
for obtaining a pH- and thermo-sensitive material. DMAEMA and AAc were grafted by direct irradiation and pre-irradiation methods,
respectively, using a 60Co γ-source. Due to the acidic and basic nature of the monomers, this novel copolymer corresponds to the class of polyzwitterions.
Their behavior was studied in presence of different buffer solutions from pH 2 to 12 for different grafting percentages (from
9 to 362%) of AAc and keeping the DMAEMA grafting percentage constant. These modified films showed the same critical pH point
at 7.6 in a range of temperatures from 23 to 37 °C. The swelling percentage showed a dependence on AAc content and pH. The
lower critical solution temperature was observed at 36 °C when AAc content was less than 30% of grafting. The grafted films
were characterized by swelling behavior, FTIR-ATR and UV–Vis spectrometry for study of loading and release of vancomycin as
a model drug at room temperature.
Authors:Z. M. H. Kheiralla, S. S. Maklad, Sanaa Mohamed Ashour, and E. El-Sayed Moustafa
The study of the bacteriological profile, the association of complement C3, interleukin-1beta, and zinc therapy of diabetic foot ulcers (type two) was investigated. Twenty diabetics without foot ulcers (group I), 50 diabetics with foot ulcers (group II), and 10 matched normal controls (group III) were enrolled in this study. Diabetic foot ulcers were mostly of grade 2. The most frequent organisms were Clostridium spp., Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli, respectively. Vancomycin, Imipenem, and Meropenem were the most effective against Gram-positive and Gram-negative aerobes, while Imipenem, Meropenem and Chloramphenicol for Gram-positive anaerobes. Group II had abnormal levels of C3 (72%). A significant higher concentration of C3 was found in group II. Group II had abnormal levels of IL-1β (60%). A significant higher concentration of IL-1β was found in group II. Zinc therapy (25 mg/day/oral) induced a highly significant decrease in the frequency of Gram-positive anaerobes and levels of IL-1β. Significantly increases all mineral concentrations in serum level except Mn+2. The study highlights the prevalence of antibiotic multidrug resistant bacteria causing foot infections in diabetics which require combined antimicrobial therapy. Altered levels of serum complement C3 and IL-1β might be responsible for depressed immune response which might be causes for delayed wound healing and repeated infections. Zinc supplementation may help in healing the wounds by enhancing the immune response.
Authors:Julia Münch, Ralf Matthias Hagen, Martin Müller, Viktor Kellert, Dorothea Franziska Wiemer, Rebecca Hinz, Norbert Georg Schwarz, and Hagen Frickmann
The effectiveness of a disinfectant-based decolonization strategy for multidrug-resistant bacteria like extended spectrum β-lactamase (ESBL)-positive Gram-negative bacteria with or without additional fluoroquinolon and carbapenem resistance as well as vancomycin-resistant enterococci and methicillin-resistant Staphylococcus aureus was assessed.
Between 2011 and 2015, 25 patients from Libya, Syria, and the Ukraine with war traumata were treated at the Bundeswehr hospital Hamburg. The patients were heavily colonized and infected with multidrug-resistant bacteria, altogether comprising 371 distinct combinations of pathogens and isolation sites. Local disinfection was assessed for effectiveness regarding successful decolonization of multidrug-resistant bacteria.
Altogether, 170 cases of successful decolonization were observed, comprising 95 (55.8%) such events at sampling sites that were accessible to disinfecting procedures. The remaining 75 (44.2%) decolonization events had to be considered as spontaneous. In contrast, 95 out of 172 (55.2%) colonized isolation sites that were accessible to disinfection procedures were successfully decolonized. Patient compliance with the enforced hygiene procedures was associated with decolonization success. Systemic antibiotic therapy did not relevantly affect isolation time.
Disinfecting washing moderately supports local decolonization of multidrug-resistant pathogens in comparison with spontaneous decolonization rates if the patients’ compliance with the applied hygiene procedures is ensured.
Authors:F. Yurt Lambrecht, O. Yilmaz, K. Durkan, P. Unak, and E. Bayrak
Linezolid is the first of new class of antibiotics, the oxazolidinones, and exhibits activity against many gram-positive organisms,
including vancomycin-resistant Enterococcusfaecium, methicillin-resistant Staphylococcusaureus, and penicillin-resistant Streptococcuspneumoniae. Aim of the study: Linezolid was to label with I-131 and potential of the radiolabeled antibiotic was to investigate in inflamed
rats with S. aureus (S.aureus) and sterile inflamed rats with turpentine oil. Linezolid was labeled with I-131 by iodogen method. Biodistribution of [131I]linezolid was carried out in bacterial inflamed and sterile inflamed rats. Radiolabeling yield of [131I]linezolid was determined as 85 ± 1% at pH 2. After injecting of [131I]linezolid into bacterial inflamed and sterile inflamed rats, radiolabeled linezolid was rapidly removed from the circulation
via the kidneys. Binding of [131I]linezolid to bacterial inflamed muscle (T/NT = 77.48 at 30 min) was five times higher than binding to sterile inflamed muscle
(T/NT = 14.87 at 30 min) of rats. [131I]linezolid showed good localization in bacterial inflamed tissue. It was demonstrated that [131I]linezolid can be used to detect S.aureus inflammation in rats.
Authors:S. Sirilun, C. Chaiyasut, D. Kantachote, and P. Luxananil
The aims of this study were to isolate LAB from Thai plant-derived foods and beverages and to examine in vitro probiotic properties including b-glucosidase enzyme activity. Lactobacillus plantarum SC 359 selected from Thai pickled soybean was significantly (P<0.05) the best to perform β-glucosidase enzyme activity (0.396 U ml−1 at 18 h of incubation) out of the 227 tested strains. The strain survived in 0.30% (w/v) bile salt and had high tolerance to acidic pH with survival rates at a 2 h period of 72.24%, 85.52%, 92.64%, and 93.38% at pH 2.0, 3.0, 4.0, and 5.0, respectively. The SC 359 strain showed proteolytic and lipolytic activities. Moreover, the selected strain displayed strong antagonistic activities against Bacillus cereus ATCC 11778, Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Salmonella Typhi, Shigella sonnei and Candida albicans ATCC 90028. The strain was susceptible to ampicillin, chloramphenicol, erythromycin, gentamicin, kanamycin, rifampicin, streptomycin, tetracycline, and vancomycin. In addition, the selected strain significantly inhibited the adherence to Caco-2 cells of E. coli, S. Typhi and Sh. sonnei (P<0.05) by 33.50 to 73.37%. The strain could obstruct the adherences of pathogens by elimination, competition, and displacement with pathogen adherences 33.62–53.92%, 26.63–59.23%, and 49.41–66.50%, respectively. Based on the results, the selected strain could be applied as functional starter for Thai fermented plant-derived foods and beverages.
Authors:Osman Tel, Özkan Aslantaş, Oktay Keskin, Ebru Yilmaz, and Cemil Demir
In this study, Staphylococcus aureus strains (n = 110) isolated from seven ewe flocks in Sanliurfa, Turkey were screened for antibiotic resistance and biofilmforming ability as well as for genes associated with antibiotic resistance and biofilm-forming ability. All isolates were found to be susceptible to oxacillin, gentamicin, clindamycin, cefoxitin, tetracycline, vancomycin, amoxicillin-clavulanic acid, ciprofloxacin and sulphamethoxazole-trimethoprim. The percent proportions of strains resistant to penicillin G, ampicillin and erythromycin were 27.2% (n = 30), 25.4% (n = 28) and 6.3% (n = 7), respectively. Regarding the antibiotic resistance genes, 32 (29%) isolates carried the blaZ and 8 (7.2%) the ermC gene. Other resistance genes were not detected in the isolates. All isolates showed biofilm-forming ability on Congo red agar (CRA), while 108 (98.18%) and 101 (91.81%) of them were identified as biofilm producers by the use of standard tube (ST) and microplate (MP) methods, respectively. All isolates carried the icaA and icaD genes but none of them harboured the bap gene. The results demonstrated that S. aureus isolates from gangrenous mastitis were mainly resistant to penicillins (which are susceptible to the staphylococcal beta-lactamase enzyme), and less frequently to erythromycin. Furthermore, all of the S. aureus isolates produced biofilm which was considered a potential virulence factor in the pathogenesis of staphylococcal mastitis.
Authors:Boris Habrun, Ivana Račić, Relja Beck, Ana Budimir, Miroslav Benić, Gordan Kompes, Silvio Špičić, and Željko Cvetnić
Methicillin-resistant Staphylococcus aureus (MRSA) have emerged worldwide and have become resistant to a variety of antibiotics. MRSA colonisation in pigs was first reported from the Netherlands in 2005, where pigs were implicated as a source of human MRSA infections (Voss et al., 2005). This paper presents the first report on the presence of MRSA on large pig breeding farms in Croatia, together with the determination of the mecA gene, the results of spa typing and susceptibility to commonly used antimicrobials. Dust samples (7–11 per farm) were collected from eight large pig farms in Croatia. Of the total 68 swabs, the mecA gene was detected in 24 isolates growing on the MRSA agar. All isolates were resistant to oxacillin, tetracycline and streptomycin, and susceptible only to vancomycin, while 92% of the strains were susceptible to ciprofloxacin. Genotyping of the MRSA strains was performed by spa typing, and revealed t011 (n = 17), t034 (n = 5) and t1451 (n = 2). The results presented here predict that MRSA is present on a large number of pig farms in Croatia.
Authors:Rossana Abreu, Cristobalina Rodríguez-Álvarez, María Lecuona, Beatriz Castro-Hernández, Juan Carlos González, Armando Aguirre-Jaime, and Ángeles Arias
The aim of this study was to determine the prevalence of methicillin-resistant Staphylococcus (MRS) in healthy goats on the Island of Tenerife, Spain, as well as to identify the phenotypic and genotypic characteristics of the strains found. A cross-sectional prevalence study was conducted. A total of 158 goats from 15 different farms were sampled between September 2017 and January 2018. The percentage of positive samples of methicillin-resistant Staphylococcus aureus (MRSA) was 15.8% (25/158) and that of methicillin-resistant coagulase-negative staphylococci (MRCoNS) was 6.9% (11/158). All MRSA isolates from goats belonged to one clonal group showing Multi-Locus Sequence type 398. All strains studied (n = 36) were resistant to non-carbapenem beta-lactam antibiotics and susceptible to teicoplanin, linezolid, vancomycin, rifampicin, quinupristin-dalfospristin and mupirocine. In MRSA isolates, the highest percentage of resistance obtained, besides beta-lactam non-carbapenem antibiotics, was to trimethoprim-sulphamethoxazole and, in the case of MRCoNS isolates, to phosphomycin and erythromycin. A total of 12 resistance patterns were obtained, presenting differences between patterns obtained for MRSA and MRCoNS, with 7 different patterns for MRSA and 5 for MRCoNS. We therefore consider it essential to expand the epidemiological study of these strains of animal origin, as well as to increase surveillance and control measures at all stages of the food chain.