Background: Streptococcus mutans is a major cause of dental caries. Its capacity to produce biofilm is fundamental in the pathogenesis of this ubiquitous condition. As maintaining a healthy dentition is a genuine goal given the contemporary advance in caries control, researchers are striving to achieve a breakthrough in caries therapy. We are taking the anti-cariogenic properties of vitamin C a step-further, considering the well-known evidence of the inversely proportionate relationship between salivary levels of vitamin C and dental caries. The aim of this study was to determine MIC, MBC, biofilm prevention concentration (BPC), and derivative measures of vitamin C against fresh clinical isolates of S. mutans to evaluate its efficacy as an anti-cariogenic agent. Results: Based on the data of four independent experiments done in quadruplicates, we found a concentrationdependent inhibitory effect of vitamin C on all S. mutans strains tested. The average MBC, MIC, and BPC of vitamin C were found to be 10.16, 9.38, and 5.61 mg/ml, respectively. Spectrophotometric quantitation of crystal violet showed diminished biofilm formation in the presence of vitamin C (p < 0.05). When compared with gentamicin, vitamin C produced a zone of inhibition that was three times as large against the clinical isolates.

Background: Small colony variants (SCVs) of bacterial pathogens are smaller, slow-growing variants which often pose a challenge to the clinical microbiologist in their identification and characterization. SCVs are receiving much attention in recent years due to their association with several types of chronic infections. In this study, we aimed to develop a suitable culture media for high frequency generation and stable maintenance of SCV of Klebsiella pneumoniae. We also intended to compare different phenotypic characteristics such as growth, antibiotic resistance pattern, and biofilm-forming potential of SCVs with the original parental strain. Methods: We used Mueller–Hinton agar containing the extract of clove (Syzygium aromaticum) for the generation of SCV. Antibiotic sensitivity was determined using disk diffusion method and minimum inhibitory concentration determinations using microdilution method. Biofilm formation was assessed using crystal violet dye binding assay. Results: Mueller–Hinton agar (MHA) containing clove (Syzygium aromaticum) extract (10% volume/volume; MHA-C10) supported generation of SCV from K. pneumoniae at high frequency. SCVs were smaller in colony size and grew slowly in comparison to the wild-type original strain. In addition, SCVs exhibited increased resistance to aminoglycoside group of antibiotics (gentamicin and kanamycin). Crystal violet dye binding spectrophotometric method showed increased biofilm formation potential by SCVs in comparison to their parental counterparts. Conclusions: The findings of this study show that MHA-C10 can be used as a bacterial culture media for the formation of SCV by K. pneumoniae. SCVs, thus, generated on MHS-C10 exhibited typical characteristics of SCVs.

Cell phones are the most common gadgets used in today’s world. Studies from different countries demonstrated that these electronic gadgets can carry different bacterial species, including potential pathogenic strains. These gadgets are in the hands of every health care professionals (HCPs) and can even be found in the operation theatres (OT). Moreover, healthcare workers tend to neglect the potential infectious threat that these gadgets carry. Hence, we investigated the microbial profile present on cell phones used by HCPs in United Arab Emirates (UAE). Standard microbiological procedures were used for collection and identification of bacterial species. Disk diffusion assay and crystal violet dye binding spectrophotometric assay were used for determining antibiogram and biofilm forming potential, respectively. Staphylococcus epidermidis was present in 64.1% of the samples, followed by Micrococci (22.3%), Streptococcus viridians (2.2%), Diphtheroids (2.9%), Bacillus spp. (5.2%), Enterobacter spp. (1.4%) and Pseudomonas spp. (1.4%). The tested strains exhibited varied degree of antibiotic resistance and biofilm producing potential. Our data highlights that mobile phones may just not be carriers for normal skin flora but also for antibiotic resistant, biofilm forming potential opportunistic pathogens and thus may serve as transmission vectors for bacteria.  This is the first report from UAE analyzing carriage of bacteria in mobile gadgets used by HCPs. Furthermore, this would help to raise awareness among the HCPs about these electronic gadgets serving as a vehicle of transmission of bacterial pathogen.

Blood Stream Infection (BSI) and Urinary Tract Infection (UTI) being leading causes of morbidity and mortality represent a common complication among critically ill patients. During the last decade, clinicians have observed a rising occurrence of BSIs due to bacterial resistance. Likewise, catheter-associated UTI is a main cause of morbidity and mortality affecting all age groups. Coliforms happen to be the prominent pathogens among our ICU admitted patients. It was alarming to notice 42.9% resistance to tigecycline among K. pneumoniae isolated from blood. K. pneumoniae isolates cultured from urine of ICU patients uniformly displayed 75% resistance to ciprofloxacin, ceftriaxone, cefoxitin and cefepime. Interestingly, it is of respite to observe 85.7% K. pneumoniae isolated from blood and 75% K. pneumoniae isolated from urine being susceptible to a conventional antibiotic, gentamicin. Escherichia coli isolated from urine were 100% susceptible to carbapenems and 91.75% were susceptible to tigecycline. Overall, 90% of Pseudomonas aeruginosa were susceptible to nitrofurantoin. The rapid spread of these MDR pathogens demands for national and regional guidelines. Policies to treat ICU related infections in UAE should be designed based on local microbiological data and resistance profiles of pathogens.

Background Streptococcus mutans is a major cause of dental caries. Its capacity to produce biofilm is fundamental in the pathogenesis of this ubiquitous condition. As maintaining a healthy dentition is a genuine goal given the contemporary advance in caries control, researchers are striving to achieve a breakthrough in caries therapy. We are taking the anti-cariogenic properties of vitamin C a step-further, considering the well-known evidence of the inversely proportionate relationship between salivary levels of vitamin C and dental caries. The aim of this study was to determine MIC, MBC, minimum biofilm inhibitory concentration (MBIC), and derivative measures of vitamin C against fresh clinical isolates of S. mutans to evaluate its efficacy as an anti-cariogenic agent.Results Based on the data of four independent experiments done in quadruplicates, we found a concentration-dependent inhibitory effect of vitamin C on all S. mutans strains tested. The average MBC, MIC, and MBIC of vitamin C were found to be 10.16, 9.38, and 5.61 mg/ml, respectively. Spectrophotometric quantitation of crystal violet showed diminished biofilm formation in the presence of vitamin C (p < 0.05). This inhibitory effect was not seen when vitamin C was added 18 hours post-inoculation, proving its inability to detach preformed biofilm. When compared with gentamicin, vitamin C produced a zone of inhibition that was three times as large against the clinical isolates.Conclusion Our results show that vitamin C has a negative effect on S. mutans growth and biofilm formation, which appears to be related to an inhibitory mechanism. Being the first to meticulously utilize MBIC to explore a well-known effect of vitamin C, this report aims to help in the instigation of trials of higher evidence that will ultimately culminate in repurposing vitamin C as a novel anti-cariogenic agent, albeit further studies are required to provide auxiliary evidence in this context.