Analysis of conjunctival sac microflora and antibiotic susceptibility testing in adolescents after wearing orthokeratology lens / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the bacterial flora and antibiotic susceptibility testing of conjunctival sac in adolescents after wearing orthokeratology(OK)lens.METHODS:A total of 101 adolescents aged 8 to 14 who admitted to outpatient department of Xi'an No.1 Hospital from September 2021 to August 2022 were recruited in this cross-sectional observational study. There were 51 cases wearing OK Lens(wearing group)and 50 patients not wearing contact lens(non-lens group), the right eye of all patients was selected into the group. The culture of bacterial flora in conjunctival sac between the two groups were compared, the species were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and the antibiotic susceptibility testing was carried out for the positive strains cultured in the wearing group.RESULTS:The positive rate of conjunctival sac bacterial cultured in the wearing group and the non-lens group was 68.6%(35/51)and 60.0%(30/50), respectively(P>0.05). In both groups, the bacteria with the highest detection rate were staphylococcus epidermidis and staphylococcus aureus. The sensitivity rates of the strains detected in the wearing group to drugs are as follows: Levofloxacin(98%), Moxifloxacin(98%), Gatifloxacin(98%), Cefuroxime(98%), Cefathiamidine(98%), Rifampicin(98%), Chloramphenicol(96%), Cefoxitin(95%), Clindamycin(80%), Gentamicin(74%), Fusidic acid(72%), Tobramycin(64%), Compound sulfamethoxazole(26%), Mezlocillin(10%), Azithromycin(6%), of which the sensitivity rate of Gram-positive cocci was 100% sensitive to Vancomycin.CONCLUSION:Gram-positive cocci are the main bacteria isolated from conjunctival sac of adolescents after wearing OK Lens. Wearing OK Lens will not significantly increase the positive rate of conjunctival sac bacterial flora. Results of antibiotic susceptibility testing may provide guidance for empirical medication in patients wearing OK lens after eye infection.

Antimicrobial resistance pattern of microorganisms isolated and identified from Godavari River across the mass gathering event

The Kumbh Mela is considered the world’s largest mass gathering event (MGE). It represents a unique anthropogenicburden on the river ecosystem and may confer antimicrobial resistance among microbial communities. The present studyexplains the characterization of microbial isolates associated with Godavari River under the advent of the mass bathingevent using culture dependent approach. The isolates were identified by sequencing of 16S rRNA gene and ITS region.Further, the isolates were screened for antibiotic susceptibility against 22 antibiotics using disc diffusion method. A total of63 bacterial and 21 fungal isolates were isolated under the temporal variation of the event. Kocuria and Staphylococcuswere the most prevalent bacterial genera in the samples collected before and during the event, while Meyerozyma andCandida predominate among fungal communities. A group of antibiotics impeding the bacterial protein synthesis werefound to be most effective against C67% of bacterial isolates. However, C37–67% of isolates could escape the action ofinhibitors of bacterial cell wall synthesis. Moreover, bacterial isolates belonging to genera Acinetobacter, Corynebacteriumand Brevibacterium showed higher resistance towards the antibiotics. Observations from the current study suggest likelymicrobial taxa as targets to mitigate the waterborne infections during the MGE.

Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry in Clinical Microbiology: What Are the Current Issues?

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) has revolutionized the identification of microbial species in clinical microbiology laboratories. MALDI-TOF-MS has swiftly become the new gold-standard method owing to its key advantages of simplicity and robustness. However, as with all new methods, adoption of the MALDI-TOF MS approach is still not widespread. Optimal sample preparation has not yet been achieved for several applications, and there are continuing discussions on the need for improved database quality and the inclusion of additional microbial species. New applications such as in the field of antimicrobial susceptibility testing have been proposed but not yet translated to the level of ease and reproducibility that one should expect in routine diagnostic systems. Finally, during routine identification testing, unexpected results are regularly obtained, and the best methods for transmitting these results into clinical care are still evolving. We here discuss the success of MALDI-TOF MS in clinical microbiology and highlight fields of application that are still amenable to improvement.

Identification and Antibiogram Profile of Streptococcus mutans and Streptococcus sobrinus from Dental Caries Subjects.

Dental caries is one of the oldest disease in the world and its causative agent is mutans streptococci (MS). Among MS, Streptococcus mutans and Streptococcus sobrinus are implicated in caries active subjects. The objective of this study was to identify and determine the antibiogram profile of S. mutans and S. sobrinus isolates. The dental plaque samples were collected from caries active subjects (aged 35-44 years) and later identified by 16S rDNA sequencing. Out of 65 clinical isolates 36 (55.38%) were S. mutans and 5 (7.69%) were S. sobrinus. Antibiogram profiling was performed to determine the susceptibility of 6 β-Lactam antibiotics (penicillin, ampicillin, cefotaxime, cephalothin, cefazolin and methicillin) and 2 non β-Lactam antibiotics (erythromycin and chloramphenicol) by disc diffusion method. All S. mutans and S. sobrinus isolates were susceptible to the antibiotics employed in this study. Penicillin and ampicillin were the most effective antibiotics against S. mutans and S. sobrinus isolates and no resistance found. The study concludes that all the isolates were susceptible to the antibiotics, and suggests that taking extra precaution while prescribing antibiotics will maintain the bacteria with less resistance. It also recommends to use an alternative prevention, such as a plant extract to avoid upcoming resistance.

Evaluation of the Quality of Commercial Antibacterial Discs Available in Nigeria.

Aims: This study was undertaken to compare the quality and efficacy of six brands of antibacterial discs that are commercially available in Nigeria. Methodology: The brands evaluated include two foreign brands (Oxoid and Abtek) and four local brands (Optudisc, Polydisc, Maxidisc and Jirehdisk). The brands were analyzed by antibiotic susceptibility testing (AST) using laboratory isolates of Staphylococcus aureus and Escherichia coli to measure the antimicrobial performances of the brands; and UV-Vis spectrophotometry to measure the absorbances of antibiotics extracted from antibiotic discs of the various brands. Results: All of the brands of antibacterial discs of under study exhibited variations in their antimicrobial performances and UV-absorbances. This was observed where some of the discs with lower stated potencies produced inhibition zones and absorbances far greater than similar discs from other brands with higher stated potencies. Also, discs of the same stated potencies showed variable results in both the antibiotic susceptibility testing (AST) and UV-Vis spectrophotometric analyses. Coefficients of variation greater than 5%, which indicates high disc-to-disc variation and unsatisfactory reproducibility, were recorded highest among the local brands during the AST. All the brands with multidisc panels, except the Abtek and Polydisc brands, produced some zones of inhibition that are unreadable. Of all the zones of inhibition that were unreadable, Optudisc brand recorded the highest rate (36·7%), while 6·7% of discs of Jirehdisk brand and 6·7% of discs of Maxidisc brand produced inhibition zones that were unreadable. Conclusion: All brands of susceptibility discs evaluated in this study except the Oxoid and Abtek brands manifested poor quality and performed below expected standard, though one of the local brands (Polydisc) performed closest to the foreign brands. With further improvement in quality, these brands may be recommended for use in Nigeria.

Aerobic bacteriology of chronic suppurative otitis media: a hospital based study.

Background: Chronic suppurative otitis media (CSOM) remains one of the most common childhood chronic infectious diseases worldwide, affecting diverse racial and cultural groups both in developing and industrialized countries. It involves considerable morbidity and can cause extra- and intra-cranial complications. The aim of this study was to determine the microbial diversity and the antibiogram of aerobic bacterial isolates among patients suffering from CSOM who attended the ENT Department of SMHS hospital, a tertiary care centre located in the heart of the Kashmir valley. Methods: A total of 154 patients clinically diagnosed with CSOM were enrolled in the study and the samples were obtained from each patient using sterile cotton swabs and cultured for microbial flora. Drug susceptibility testing for aerobic isolates was conducted using Kirby-Bauer disc diffusion method. Results: Out of total 154 ear swabs processed, microbial growth was seen in 138 (89.61%) while 16 (10.38%) samples showed no growth. In 102 (66.23%) samples mono-microbial growth was seen whereas 26 (16.88%) samples showed poly-microbial growth. The most frequent organism isolated was Pseudomonas aeroginsa followed by Staphylococcus aureus and Proteus sp. The most effective antibiotic against Pseudomonas aeroginsa was amikacin followed by imipenem and piperacillin plus tazobactam, while as Staphylococcus aureus showed maximum sensitivity to vancomycin. Conclusion: Otitis media linked with high levels of multiple antibiotic resistant bacteria is a major health concern in all age groups of the study population. An appropriate knowledge of the etiology and antibacterial susceptibility of microorganisms would contribute to a rational antibiotic use and the success of treatment for chronic supportive otitis media.

Extended-spectrum β-lactamase and AmpC β-lactamase Production among Gram-negative Bacilli Isolates Obtained from Urinary Tract Infections and Wound Infections.

Extended-spectrum β-lactamases (ESBLs) and AmpC β-lactamases continue to be a major problem in healthcare settings. Due to the scarcity of information regarding the antibiotic susceptibility patterns particularly from urinary tract infections (UTIs) and wound infections, the current study was carried out to assist the clinicians to prescribe appropriate antibiotics against gram-negative clinical isolates. In the current study, urine (n = 620) and pus (n = 228) samples were collected from different sites (at various clinical departments) and subjected to direct microscopic examination, culture and antibiotic susceptibility testing (AST). In the AST testings, the isolates that exhibited reduced zone of inhibition to one or more of the antibiotics such as cefotaxime (≤27 mm), ceftriaxone (≤25 mm), ceftazidime (≤22 mm), cefpodoxime (≤17 mm) and aztreonam (≤27 mm) were considered as potential ESBL producers and the ESBL production was confirmed using phenotypic screening test (doubledisk synergy test) and phenotypic confirmatory test (combined-disk test). However, isolates showing resistance or decreased sensitivity to cefoxitin, cefotaxime, ceftriaxone, ceftazidime, cefpodoxime or aztreonam and sensitive to cefepime were considered as a screen positive AmpC producer and subjected to AmpC disk tests. The current study concluded that 72.41% and 21.76% of ESBL and AmpC producers were detected, respectively in our hospital. It was also observed that the double-disk synergy and combined-disk tests were equally effective for ESBL detection. Further, AmpC disk test is simple, easy to perform and interpret, requiring less expertise for the rapid detection of AmpC isolates.

Antibiotic resistance patterns of Pseudomonas aeruginosa in a tertiary care hospital in Central India.

Background: Antimicrobial resistance is the major problem of the modern world, thus it needs urgent attention. Pseudomonas aeruginosa has the inherent property of developing the resistance. Hence, it is necessary to know the current resistance pattern for proper use of antipseudomonal agents. Aims & Objective: (i) To evaluate the antibacterial resistance pattern in Pseudomonas aeruginosa in a tertiary care hospital in Central India; (ii) To provide base for formulating rational antibacterial guidelines to treat the infections caused by pseudomonas aeruginosa. Material and Methods: The present study was an observational, longitudinal study over a period of three years from April 2007 to March 2010. The necessary data was obtained from Central Microbiology Laboratory of Government Medical College, Nagpur, India. Total 1001 samples were reported the presence of Pseudomonas aeruginosa in all the 11 types of biological sample. Antimicrobial susceptibility testing was performed using disk diffusion method with Pseudomonas species ATCC 27853, as per CLSI guidelines. Appropriate statistical analysis methods were applied to the data to fulfil the objectives of the study with the latest version of Graph pad prism software. Results: Pus samples showed highest culture positivity for P. aeruginosa followed by sputum. The highest resistance was reported to ciprofloxacin while the lowest resistance to Meropenem. Conclusion: Wound infection was the most common hospital acquired infection. The use of Meropenem and Amikacin should be restricted to avoid the emergence of resistance against them. Such studies should be performed regularly to recognize the recent trends.

Epidemiology and Resistance Patterns of Bacterial Pathogens in Urinary Tract Infections in the Northern Gyeonggi-do Area during 2007-2011

BACKGROUND: Bacteria that cause urinary tract infections (UTIs) are found with different frequencies in different regions; moreover, antibiotic susceptibility can also vary by region. We retrospectively studied and compared the species and antimicrobial susceptibility of bacterial pathogens isolated from patients with UTIs in the northern Gyeonggi-do area. METHODS: We analyzed urine specimens collected from patients who visited the Myongji Hospital between 2007 and 2011. The urine specimens were cultured, and bacteria were identified by biochemical examination with an API kit (bioMerieux Inc., USA). Antimicrobial susceptibility was determined by the disc diffusion method and the Vitek II system (bioMerieux Inc., USA). RESULTS: A total of 11,818 (31.4%) urine specimens were culture positive. The most common species identified were Escherichia coli (37.1%), Klebsiella pneumoniae (7.4%), Enterococcus faecium (6.1%), and Candida spp. (5.5%). The proportion of isolates producing extended-spectrum beta-lactamases significantly increased during the study period. CONCLUSIONS: E. coli, K. pneumoniae, and E. faecium were the 3 most common organisms identified. Of note, however, was the increasing frequency of Pseudomonas spp. and Proteus spp. isolated during the more recent years. Further studies are required from other centers in the northern Gyeonggi-do area.

Antimicrobial Resistance of Nonfermentative Bacteria in Lower Respiratory Tract Infection / 中华医院感染学杂志

OBJECTIVE To investigate the epidemic situation of nonfermentative bacteria in lower respiratory tract infection and guide rational use of antimicrobials.METHODS API system was applied for bacterial identification.K-B disk diffuse method was used in susceptibility testing.WHONET 5.3 software was used for data analysis.Pseudomonas aeruginosa,Acinetobacter baumannii and Stenotrophomonas maltophilia isolates were included in this study.RESULTS Less than 20% of P.aeruginosa isolates were resistant to amikacin,imipenem or cefoperazone/sulbactam.For A.baumannii,the most active compounds tested were imipenem and cefoperazone/sulbactam with resistance rates of 4.8% and 7.3%,respectively.26.6% And 27.4% of A.baumannii isolates were resistant to piperacillin/tazobactam and ticarcillin/clavulanic acid.The resistance rate of S.maltophilia to cefoperazone/sulbactam,ticarcillin/clavulanic acid and piperacillin/tazobactam was 0,2.7% and 10.8%,respectively.CONCLUSIONS The isolation rate of nonfermenters is increasing in the lower respiratory tract infection,and the ways to improve the cure rate are to avert nosocomial infection and choose antimicrobials properly.

Pathogenic Analysis of Pelvic and Peritoneal Abscess and Its Clinical Management / 中华医院感染学杂志

OBJECTIVE To explore the pathogenesis of pelvic and peritoneal abscesses and their clinical(management).METHODS Clinical data of 109 patients with pelvic and peritoneal abscesses between 1999 and 2005 were retrospectively(evaluated).The connection of their pathogenesis,antibiotics choice,and treatment types with(prognoses) was analyzed.RESULTS Pus from all patients was collected and sent to do germ culture and antibiotic susceptibility testing.Seventy five cases were with positive germ culture.The most germs were Escherichia coli and meropenem and amikacin were considered effective.Four cases were relapsed after surgery from 90 cases.(Pelvic) abscess drainage was performed through vagina under B type ultrasound guiding in 9 cases.Conservative treatment was given in 10 cases and no patient died.CONCLUSIONS Pelvic and peritoneal abscesses should be treated early with antibiotic according susceptibility testing to make a choice.And surgery or sufficient abscess drainage can(improve) their prognosis.