Aerobic Gram-negative Bacteria Research Articles

Quantitative Analysis of Selected Microorganisms Present at Various Sites in a Prosthetics Clinic and Dental Laboratory during Complete Denture Fabrication.

Background: Contamination with oral commensals and pathogenic microorganisms, and cross contamination between clinic and laboratory can occur. The amount of contamination has not been determined. Methods: Samples from different clinical and laboratory stages before and after disinfection (17 sites, 10 samples per stage) were collected. Laboratory surfaces and equipment were swabbed for 10 days (11 sites). Swabs were cultured for total mixed flora, Streptococci, Lactobacilli, Staphylococcus aureus, aerobic Gram-negative bacteria (AGNB) and Candida. Knowledge of infection control among staff and students was assessed. Results: Clinic: In total, 30–40% of the samples overall were contaminated with mixed flora and Streptococci of >100 cfu/swab; >100 cfu of AGNB and Candida were present on 6% and 1% of samples; 2% contained <100 cfu of S. aureus. Laboratory: In total, 17–48% of the samples overall were contaminated with mixed flora and Streptococci of >100 cfu/swab; >100 cfu of AGNB were present on 11% of samples; none contained >100 cfu of Candida. Disinfection significantly reduced the level of all organisms. Knowledge of infection control was sufficient, but compliance was poor. Conclusion: Although the count of mixed flora was high, potential pathogens such as S. aureus and Candida were low. In immunocompromised patients, this can become a problem.

Omadacycline: A Novel Oral and Intravenous Aminomethylcycline Antibiotic Agent

Omadacycline is a novel aminomethylcycline antibiotic developed as a once-daily, intravenous and oral treatment for acute bacterial skin and skin structure infection (ABSSSI) and community-acquired bacterial pneumonia (CABP). Omadacycline, a derivative of minocycline, has a chemical structure similar to tigecycline with an alkylaminomethyl group replacing the glycylamido group at the C-9 position of the D-ring of the tetracycline core. Similar to other tetracyclines, omadacycline inhibits bacterial protein synthesis by binding to the 30S ribosomal subunit. Omadacycline possesses broad-spectrum antibacterial activity against Gram-positive and Gram-negative aerobic, anaerobic, and atypical bacteria. Omadacycline remains active against bacterial isolates possessing common tetracycline resistance mechanisms such as efflux pumps (e.g., TetK) and ribosomal protection proteins (e.g., TetM) as well as in the presence of resistance mechanisms to other antibiotic classes. The pharmacokinetics of omadacycline are best described by a linear, three-compartment model following a zero-order intravenous infusion or first-order oral administration with transit compartments to account for delayed absorption. Omadacycline has a volume of distribution (Vd) ranging from 190 to 204L, a terminal elimination half-life (t½) of 13.5-17.1h, total clearance (CLT) of 8.8-10.6L/h, and protein binding of 21.3% in healthy subjects. Oral bioavailability of omadacycline is estimated to be 34.5%. A single oral dose of 300mg (bioequivalent to 100mg IV) of omadacycline administered to fasted subjects achieved a maximum plasma concentration (Cmax) of 0.5-0.6mg/L and an area under the plasma concentration-time curve from 0 to infinity (AUC0-∞) of 9.6-11.9mgh/L. The free plasma area under concentration-time curve divided by the minimum inhibitory concentration (i.e., fAUC24h/MIC), has been established as the pharmacodynamic parameter predictive of omadacycline antibacterial efficacy. Several animal models including neutropenic murine lung infection, thigh infection, and intraperitoneal challenge model have documented the in vivo antibacterial efficacy of omadacycline. A phase II clinical trial on complicated skin and skin structure infection (cSSSI) and three phase III clinical trials on ABSSSI and CABP demonstrated the safety and efficacy of omadacycline. The phase III trials, OASIS-1 (ABSSSI), OASIS-2 (ABSSSI), and OPTIC (CABP), established non-inferiority of omadacycline to linezolid (OASIS-1, OASIS-2) and moxifloxacin (OPTIC), respectively. Omadacycline is currently approved by the FDA for use in treatment of ABSSSI and CABP. Phase II clinical trials involving patients with acute cystitis and acute pyelonephritis are in progress. Mild, transient gastrointestinal events are the predominant adverse effects associated with use of omadacycline. Based on clinical trial data to date, the adverse effect profile of omadacycline is similar to studied comparators, linezolid and moxifloxacin. Unlike tigecycline and eravacycline, omadacycline has an oral formulation that allows for step-down therapy from the intravenous formulation, potentially facilitating earlier hospital discharge, outpatient therapy, and cost savings. Omadacycline has a potential role as part of an antimicrobial stewardship program in the treatment of patients with infections caused by antibiotic-resistant and multidrug-resistant Gram-positive [including methicillin-resistant Staphylococcus aureus (MRSA)] and Gram-negative pathogens.

In silico genome analysis of an acid mine drainage species, Acidiphilium multivorum, for potential commercial acetic acid production and biomining

The genome of Acidiphilium multivorum strain AIU 301, acidophilic, aerobic Gram-negative bacteria, was investigated for potential metabolic pathways associated with organic acid production and metal uptake. The genome was compared to other acidic mine drainage isolates, Acidiphilium cryptum JF-5 and Acidithiobacillus ferrooxidans ATCC 23270, as well as Acetobacter pasteurianus 386B, which ferments cocoa beans. Plasmids between two Acidiphilium spp. were compared, and only two of the sixteen plasmids were identified as potentially similar. Comparisons of the genome size to the number of protein coding sequences indicated that A. multivorum and A. cryptum follow the line of best fit unlike A. pasteurianus 386B, which suggests that it was improperly annotated in the database. Pathways between these four species were analyzed bioinformatically and are discussed here. A. multivorum AIU 301, shares pathways with A. pasteurianus 386B including aldehyde and alcohol dehydrogenase pathways, which are used in the generation of vinegar. Mercury reductase, arsenate reductase and sulfur utilization proteins were identified and discussed at length. The absence of sulfur utilization proteins from A. multivorum AIU 301 suggests that this species uses previously undefined pathways for sulfur acquisition. Bioinformatic examination revealed novel pathways that may benefit commercial fields including acetic acid production and biomining.

Clinical and microbiological characteristics of periprosthetic hip and knee infections

Objective. To characterize periprosthetic joint infection in patients undergoing a total hip and knee joint replacement. Materials and Methods. A total of 77 patients with periprosthetic infection following hip and knee joint replacement hospitalized in Grodno City Clinical Hospital were studied over the period of 2014-2018. Wound discharge, tissue samples, and fistula’s wall swab were used for microbiological tests. The analysis of surgical treatment of patients with deep periprosthetic knee and hip joint infection has been performed. Results. Periprosthetic infection after hip joint arthroplasty was observed in 32 (41.6%) patients, and after total knee joint arthroplasty in 45 (58.4%) patients. Surgical treatment was performed in 18 (56.3%) and 32 (71.1%) patients with periprosthetic infection following total knee and hip joint replacement, respectively. A total of 10 (31.2%) of 32 cultures from patients with periprosthetic infection after total hip joint replacement and 8 (17.8%) of 45 cultures from patients with periprosthetic infection after total knee joint replacement were positive. Overall, Staphylococcus aureus was detected in 9 (50%) of 18 positive cultures. Gram-negative aerobic bacteria (Acinetobacter baumannii, Klebsiella pneumoniae Pseudomonas aeruginosa) were detected in 4⁄10 and 5⁄8 of positive cultures from patients with periprosthetic infection of hip and knee joints, respectively. Conclusions. The most common pathogens causing periprosthetic infection of hip and knee joints were S. aureus (50%) and Gram-negative bacteria. The surgical treatment was performed in 71.4% of patients with periprosthetic joint infection.

Effects of ciprofloxacin on chicken blood parameters after an experimental infection

The objective of this paper is to study the dynamics of blood parameters in chicken resulting from use of Ciprofloxacin. Ciprofloxacin is more active in affecting aerobic Gram-negative bacteria and Staphylococci. To study the dynamics, formed three groups of chickens (1st group — control; 2nd and 3rd groups – experimental groups), which included crossbred Hisex Brown roosters. The experimental infection of chickens in the 2nd and 3rd group with Staphylococcus aureus culture performed. One day before and during four days after infection chickens in the 3rd group received 200 mg/L of Ciprofloxacin dissolved in water. Blood samples were drawn from all subjects on the day of infection, and then at the 2nd, 4th and 6th day after infection. The following blood parameters: red blood cell count, hemoglobin level, white blood cell count, and leucograms were studied. Analysis of the data we obtained showed significant changes in some parameters of white blood cells in the 2nd and third groups in comparison to the control group. We found inflammatory response which was characterized by significant increase in the absolute count and percentage of pseudo-eosinophils, monocytes and basophils in the 2nd and 3rd groups in comparison to the control group.

Antimicrobial resistance of gram-negative pathogens isolated from hospitalized patients in Rostov region

Objective. To evaluate resistance rates to carbapenems and III–IV generation cephalosporins among gramnegative bacteria, including production of carbapenemases and extended-spectrum beta-lactamases (ESBL). Materials and Methods. A total of 460 gram-negative bacteria isolated from hospitalized patients aged 1 to 85 years from 8 medical institutions of Rostov-on-Don and the region from April 2018 to December 2019 were tested by conventional microbiological methods. The most common acquired carbapenemases genes were determined by real-time PCR using commercial kits (Central Research Institute of Epidemiology, Russia). Results. The tested isolates included 180 (39.1%) isolates of K. pneumoniae, 87 (18.9%) – E. coli, 101 (22.0%) – A. baumannii and 92 (20.0%) – P. aeruginosa. K. pneumoniae and E. coli isolates exhibited the high resistance rates to cefotaxime – 96.7% and 71.2%, to ceftazidime – 95.5% and 54.0%, and to cefepime – 95.5% and 54.0%, respectively. ESBL production was detected in 35.0% and 78.2% of K. pneumoniae and E.coli isolates, respectively. K. pneumoniae and E. coli isolates were resistant to imipenem, meropenem, and ertapenem: 57.8% and 3.4%; 55.0% and 2.3%; 60.0% and 4.6%, respectively. Carbapenemase production was detected in 27.8% of K. pneumoniae and 4.6% of E. coli isolates. The most common beta-lactamases were metallo-beta-lactamases (NDM) and serine carbapenemases (OXA-48). A. baumannii isolates showed the high resistance rates to imipenem and meropenem (87.1% and 85.1%). The most common beta-lactamases were metallo-beta-lactamases (NDM) and serine carbapenemases (OXA-24⁄40 and OXA-23). P. aeruginosa isolates also showed the high resistance to carbapenems – imipenem (61.9%) and meropenem (58.7%). The most common betalactamases were metallo-beta-lactamases (VIM) and GES-5. Conclusions. The results of this microbiological study indicate the extremely high prevalence of aerobic gram-negative bacteria in different infections. A. baumannii, P. aeruginosa, K. pneumoniae and E. coli isolates being resistant to third- and fourth-generation cephalosporins and carbapenems are particularly dangerous, especially due to production of ESBL and carbapenemases. The most clinically important are OXA and NDM beta-lactamases.

Detection of Virulence Factors and Antibiotic Resistance Pattern of Clinical and Intensive Care Unit Environmental Isolates of Pseudomonas aeruginosa.

Pseudomonas aeruginosa is a gram-negative non-glucose fermenting aerobic bacteria and an opportunistic pathogen in humans and animals. The present study was carried out to investigate the distribution of virulence factors and antibiotic resistance properties of P. aeruginosa isolated from patients and intensive care unit (ICU) environment. A total of 116 P. aeruginosa isolated from patients and ICU environment were collected from Besat hospital in Hamadan, the West of Iran. P. aeruginosa isolates were analyzed based on the presence of the virulence factors encoding genes included exoA, exoS, exoU, and algD using polymerase chain reaction (PCR). Antimicrobial susceptibility test was performed using a disk diffusion method. The results showed the prevalence of exoA 33 (56.9%), exoS 21 (36.20%), exoU 37 (63.8%), and algD 35 (60.34%) genes in ICU environment P. aeruginosa strains and exo A 23 (39.25%), exoS 25 (43.1%), exoU 40(68.98%), and algD 25 (43.1%) genes in clinical isolates of P. aeruginosa. High resistance levels of the clinical and ICU environment isolate to ampicillinsulbactam (100%), were also observed. Our findings should raise awareness about antibiotic resistance in hospitalized patients in Iran. Clinicians should exercise caution in prescribing antibiotics, especially in cases of human infections.

Optimizing microbiome sequencing for small intestinal aspirates: validation of novel techniques through the REIMAGINE study

BackgroundThe human small intestine plays a central role in the processes of digestion and nutrient absorption. However, characterizations of the human gut microbiome have largely relied on stool samples, and the associated methodologies are ill-suited for the viscosity and low microbial biomass of small intestine samples. As part of the REIMAGINE study to examine the specific roles of the small bowel microbiome in human health and disease, this study aimed to develop and validate methodologies to optimize microbial analysis of the small intestine.ResultsSubjects undergoing esophagogastroduodenoscopy without colon preparation for standard of care were prospectively recruited, and ~ 2 ml samples of luminal fluid were obtained from the duodenum using a custom sterile aspiration catheter. Samples of duodenal aspirates were either untreated (DA-U, N = 127) or pretreated with dithiothreitol (DA-DTT, N = 101), then cultured on MacConkey agar for quantitation of aerobic gram-negative bacteria, typically from the class Gammaproteobacteria, and on blood agar for quantitation of anaerobic microorganisms. DA-DTT exhibited 2.86-fold greater anaerobic bacterial counts compared to DA-U (P = 0.0101), but were not statistically different on MacConkey agar.DNA isolation from DA-U (N = 112) and DA-DTT (N = 43) samples and library preparation for 16S rRNA gene sequencing were also performed using modified protocols. DA-DTT samples exhibited 3.81-fold higher DNA concentrations (P = 0.0014) and 4.18-fold higher 16S library concentrations (P < 0.0001) then DA-U samples. 16S rRNA gene sequencing revealed increases in the detected relative abundances of obligate and facultative anaerobes in DA-DTT samples, including increases in the genera Clostridium (false discovery rate (FDR) P = 4.38E-6), Enterococcus (FDR P = 2.57E-8), Fusobacterium (FDR P = 0.02) and Bacteroides (FDR P = 5.43E-9). Detected levels of Gram-negative enteropathogens from the phylum Proteobacteria, such as Klebsiella (FDR P = 2.73E-6) and Providencia (FDR P < 0.0001) (family Enterobacteriaceae) and Pseudomonas (family Pseudomonadaceae) (FDR P = 0.04), were also increased in DA-DTT samples.ConclusionsThis study validates novel DTT-based methodology which optimizes microbial culture and 16S rRNA gene sequencing for the study of the small bowel microbiome. The microbial analyses indicate increased isolation of facultative and obligate anaerobes from the mucus layer using these novel techniques.

194. Description of Positive Blood Culture Results not Identified by Verigene Informs Empiric Antibiotic Selection

BackgroundBloodstream infections are a leading cause of mortality amongst hospitalized patients. Optimizing time to pathogen identification and receipt of appropriate antibiotic therapy significantly decreases mortality, morbidity, and length of hospitalization. Rapid diagnostic tests, such as Verigene, assist in the early identification of bacteria and resistance determinants from positive blood cultures; however, Verigene assays are limited to the detection of 13 gram-positive and 9 gram-negative bacteria.MethodsThe purpose of this study was to describe gram-negative and gram-positive aerobic bacteria identified from positive blood cultures with no Verigene target detected and to use the susceptibilities to create an antibiogram to assist in empiric antibiotic selection. A total of 2325 positive blood cultures resulted between January 2017 and October 2018 underwent Verigene testing.ResultsOf the 2325 isolates, 383 (16.5%), had no Verigene organism or resistance mechanism detected. Of these, there were 239 (62.4%) gram-positive isolates, 141 (36.8%) gram-negative isolates, and 3 yeast isolates with 96 unique organisms. Seventy-six (19.8%) of the organisms identified by standard culture, but not Verigene testing, are included on Verigene panel. We analyzed nine common antibiotics active against gram-negative organisms to determine percent susceptibilities against the isolated aerobic pathogens: amikacin (92.1%), cefepime (93.5%), ceftazidime (94.0%), ceftriaxone (79.7%), ciprofloxacin (88.5%), gentamicin (91.9%), levofloxacin (86.9%), piperacillin–tazobactam (83.8%), and tobramycin (85.5%). Additionally, four antibiotics active against gram-positive organisms were analyzed for gram-positive susceptibilities: cefotaxime (91.8%), ceftriaxone (98.1%), levofloxacin (82.5%), and vancomycin (91.8%).ConclusionThe results of this study provide clinicians with antibiotic susceptibilities against organisms that were not identified through Verigene to better guide timely and appropriate antibiotic therapy against gram-negative and gram-positive aerobic bacteria.Disclosures All authors: No reported disclosures.

Evaluation of Drug Susceptibility of Microorganisms in Odontogenic Inflammations and Dental Surgery Procedures Performed on an Outpatient Basis.

Bacterial infections are the most common cause of purulent soft tissue inflammations in the head and neck area. These bacteria are also responsible for the majority of inflammatory complications after third molar removal. The key to success of antibacterial treatment in both cases is the use of an appropriate antibacterial agent. The aim of the study was to evaluate the susceptibility profile of bacteria isolated from material collected from patients with intraoral odontogenic abscesses. The test material consisted of swabs taken from the odontogenic abscesses, after their incision and drainage. Another swab was collected from the lesion area, 10 days after the initial visit. Results were compared with an identical study conducted on a control group of healthy patients, who had undergone third molar removal. Bacteria identified in this study consisted of aerobic and anaerobic strains, both Gram-positive and Gram-negative. According to the EUCAST guidelines, none of the tested antibiotics was recommended for all identified bacteria. The percentage of bacterial strains sensitive to amoxicillin and clavulanic acid was 78.13% and 81.48% in the study and control groups, respectively, whereas, the percentage of those sensitive to clindamycin was 96.43% and 80.00%, respectively. For Gram-negative aerobic bacteria, gentamicin and ciprofloxacin were among medications affecting all cultured species. 100.00% of strains were found to be susceptible to these antibiotics. Statistically significant relationship between the presence of Gram-negative aerobic strains and the occurrence of complications was found. In the case of the most frequently occurring bacteria in the study, amoxicillin with clavulanic acid and clindamycin were shown to be very effective. In cases of severe purulent odontogenic inflammations, it is recommended to use a combination of antibiotics. Amoxicillin with ciprofloxacin and clindamycin with cefuroxime seem to be the proper choices based on the results of this study.

UNUSUAL PATH FOR DISCOVERY OF SEPSIS ETIOLOGY

SESSION TITLE: Wednesday Medical Student/Resident Case Report Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/23/2019 09:45 AM - 10:45 AM INTRODUCTION: Sepsis-3 defines sepsis as a life-threatening organ dysfunction caused by dysregulated host response to infection. The most challenging patients are the ones who have no clear source of infection. Current guidelines recommend empiric coverage for aerobic gram-positive and aerobic enteric gram-negative bacteria. When broad spectrum antibiotics fail, review of antibacterial spectra of activity and assistance of differential diagnosis generators may pave the path for culprit discovery. We present a case where the differential diagnosis generator helped us accurately diagnose and guide the appropriate therapy. CASE PRESENTATION: A female of 70-years with a history of osteoarthritis presented with four weeks of fever, weight loss, night sweats, and fatigue. She was hypotensive, febrile, tachycardic and tachypneic. Sepsis protocol was activated. Laboratory data revealed WBC 2.7 K/UL, Hgb 9.8 g/dL, PLT 77 K/DL, AST 71 IU/L ALT 49 IU/L, CRP 12 mg/dL, ESR 41 mm/hr. Ferritin 7138 ng/mL, LDH 570 IU/L. She failed to improve for the first 48 hours despite IV Vancomycin and Cefepime. A contrast-enhanced CT scan of the abdomen revealed splenic hypodensities; laboratory workup for Q-fever, RMSF, salmonella, and Lyme’s disease was sent to evaluate for secondary hemophagocytic lymphohistiocytosis (HLH). A liver biopsy was also obtained. Lack of clinical and laboratory improvement prompted us to review our empiric coverage. The clinical picture was thought to be secondary to an infection, therefore, we had narrowed our antibiotics to only doxycycline for non-enteric gram-negative bacilli. We also utilized Isabel Healthcare Differential Diagnosis (DDX) Tool, which generated ten differential diagnosis including Brucellosis. Our patient later admitted to consuming homemade cheese on her last visit to Mexico. Brucella serology and blood cultures were obtained. Fever resolved 48 hours after doxycycline was initiated. Later, blood cultures grew Brucella spp. Currently, our patient remains symptom-free and all laboratory abnormalities have normalized. DISCUSSION: Sepsis guidelines recommend empiric coverage for common pathogens with no clear advice on uncommon infectious agents. A detailed travel and social history are crucial, especially in patients who do not improve on empiric broad spectrum antibiotics. In addition, medical decision making relies on pattern recognition of illness scripts accumulated over time. Historically, we refer to textbooks for the DDX of each symptom. Nowadays, we have more sophisticated DDX generators that incorporate epidemiological data, clinical and laboratory findings to create a DDX list. In a study, the pooled accurate diagnosis retrieval rate for DDX tools was as high as 0.70. CONCLUSIONS: It is imperative to identify significant and clinically relevant data. DDX generators may be useful resources for clinicians and it may also increase the medical knowledge. Reference #1: PMID: 26157077 DISCLOSURES: No relevant relationships by Jose Zabala-Genovez, source=Web Response

Loggerhead sea turtles as sentinels in the western Mediterranean: antibiotic resistance and environment-related modifications of Gram-negative bacteria.

Sea turtles possess relevant characteristics to serve as sentinel species for monitoring the health of marine ecosystems, which is currently threatened. This study examined 35 loggerhead turtles from the western Mediterranean, focusing on the oral and cloacal prevalence of aerobic Gram-negative bacteria, their antibiotic resistance and the influence of several variables linked both to the animal and the environment (i.e. estimated life stage; area, season and cause of recovery; plastic ingestion). Conventional bacteriology methods led to the isolation of bacterial families commonly regarded as opportunistic pathogens (i.e. Aeromonadaceae; Enterobacteriaceae; Pseudomonadaceae; Shewanellaceae; Vibrionaceae), but pointing out sea turtles as carriers of potential zoonotic agents. The high rates of antibiotic resistance, here detected, raise important concerns on the dissemination of this phenomenon in marine environments. Moreover, several of the examined variables showed a significant influence on the prevalence of bacterial families, strengthening the role of sea turtles as mirrors of their ecosystems.

Sarecycline: a narrow spectrum tetracycline for the treatment of moderate-to-severe acne vulgaris.

Sarecycline is a novel, narrow-spectrum, once-daily tetracycline-derived oral antibiotic that is FDA-approved in the US to be taken with or without food for moderate-to-severe acne vulgaris for ages 9 years of age and older. Sarecycline possesses anti-inflammatory properties and potent activity against Gram-positive bacteria, including activity against multiple strains of Cutibacterium acnes, while exhibiting minimal activity against enteric aerobic Gram-negative bacteria. Unlike many acne studies, sarecycline was investigated for chest and back acne. Significant reduction in inflammatory lesions was seen at week 12 at 1.5 mg/kg/day of sarecycline, with statistically significant improvement seen as early as week 3. No reports of phototoxicity, dizziness, pseudotumor cerebri or lupus but 1.2% nausea and 1.2% vaginal candidiasis was reported in the pivotal Phase III studies.

‘Candidatus Bartonella dromedarii’ in the dromedary camels of Iran: Molecular investigation, phylogenetic analysis, hematological findings, and acute-phase proteins quantitation

The genus Bartonella is comprised of Gram-negative coccobacilli, aerobic, and facultative intracellular bacteria which are transmitted by hematophagous vectors (e.g., fleas, lice, sandflies, and ticks). Each species of Bartonella infects one or few related mammals as reservoir host(s). If a Bartonella spp. infects a nonspecific host like humans, it can lead to a more acute disease. Bartonella spp. has been detected more recently for the first time in camels in Israel by Rasis and colleagues. However, the epidemiological and public health importance of this new pathogen in camels is not clear. In this study, we aimed to detect the Bartonella spp. in the blood samples of Iranian camels, measure their prevalence, and determine their species. Also, the relationship between Bartonella spp. infection and different hematological factors and acute-phase proteins (Hp, a1AGP, SAA) was investigated. Finally, the sequences of three DNA regions, i.e.16S rDNA, rpoB, and ITS, were determined and phylogenetically analyzed. From the 106 examined blood samples of camels from Fars province (southern area of Iran), 18 samples were positive (17%). The findings also showed that Bartonella spp. positive camels had significantly lower Hb, MCH, and MCHC but higher RDW, SAA, and WBC (P < 0.05) compared to the control group. Our Bartonella strain was genetically similar to the ‘Candidatus Bartonella dromedarii’ but different from Bartonella bovis. Thus, more studies are required to investigate the phenotypic and genotypic characteristics of ‘Candidatus Bartonella dromedarii’. Also, there is a need to evaluate precisely the risk factors, transmission routes, and zoonotic potential of this species.

Frequency and Susceptibility Pattern of Extended Spectrum Beta Lactamase Producing Aerobic Gram Negative Bacteria in Post-Operative Infections

Extended spectrum β-lactamases occur commonly in the aerobic Gram negative bacteria (AGNB) such as <i>E. coli</i>, <i>Klebsiella</i> spp., <i>Proteus</i> spp., <i>Pseudomonas aeruginosa</i>, <i>Acinetobacter</i> spp., etc. and have the ability to make these organisms resistant to cephalosporins (e.g. ceftazidime, ceftriaxone, cefotaxime etc.), penicillins, and monobactams, i.e. aztreonam. However theses antibiotics become sensitive in the presence of clavulanic acid, an extended spectrum beta-lactamase (ESBL) inhibitor. ESBL enzymes do not influence cephamycins or carbapenems, i.e. meropenem, imipenem, etc. Major problems in surgery is wound infections after operations. High risks of wound infections are due to being immune-comprised on antibiotics, prolonged hospitalization and other factors in many cases. The current research determined various aerobic gram negative bacteria in post-operative wound infections at the College of Medical Laboratory Technology, the National Institute of Health, Islamabad, Pakistan. It also determined the frequency of ESBL in the organisms and established their susceptibility profile during the time period of the research. Infections caused by ESBL producers are a major problem in our post-operative patients. The commonest isolate was <i>E. coli</i> and the commonest ESBL producer was <i>Klebsiella</i> spp. Double disk synergy test is an effective method for screening of such isolates, and the practice of incorporating this test along with the routine sensitivity is recommended.

Characterization of Labrenzia polysiphoniae sp. nov. isolated from red alga Polysiphonia sp.

A group of five Gram-negative aerobic halophilic bacteria was isolated from the red alga Polysiphonia sp. specimen collected from the Sea of Japan seashore and subjected to a taxonomic study. On the basis of 16S rRNA gene sequence analysis, the novel isolates were affiliated to the genus Labrenzia sharing the highest gene sequence similarities of 98.1-98.4% with the type strain of Labrenzia suaedae KACC 13772T. The DNA-DNA hybridization values of 83-91% obtained between five novel strains, and 26 and 36% between two of the five novel strains and the closest neighbor Labrenzia suaedae KACC 13772T confirmed their assignment to the same separate species. Novel isolates were characterized by Q-10 as the major ubiquinone, by the predominance of C18:1ω7c followed by 11-methyl C18:1ω7c and C14:0 3-ОН in their fatty acid profiles. Polar lipids consisted of phosphatidylcholine, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylglycerol, an unknown aminophospholipid, and an unknown phospholipid. Some of novel strains were found to inhibit growth of Gram-negative and Gram-positive test microorganisms. On the basis of phylogenetic analysis, DNA-DNA hybridization and phenotypic traits, a novel species with the name Labrenzia polysiphoniae sp. nov. (type strain KMM 9699T = rh46T = KACC 19711T),is proposed.

A strategy of antimicrobial therapy of pelvic inflammatory diseases at antibiotic resistance of microbial pathogens

Relevance. Antibiotic resistance of microbial pathogens is an interdisciplinary and interstate problem of major medical and socio-economic importance. If multiresistant microbial flora is detected in patients with acute or chronic forms of pelvic inflammatory diseases alternative antimicrobial combined therapy an advisability should be considered. Current trends of an increase in multiresistant gram-negative infections along with limited range of alternative treatment options dictate a need for further research. Study of alternative antibiotics effectiveness in pelvic inflammatory diseases treatment is necessary for a further development of optimal treatment regimens. Aim. To search for adequate combinations of antimicrobial therapy aimed at antibiotic-resistant pathogens. Materials and methods. To write this review a search for domestic and foreign publications in Russian and international search systems (PubMed, eLibrary, etc.) for the last 2-12 years was conducted. The review includes articles from peer-reviewed literature. Results. Fosfomycin possesses a broad spectrum of antibacterial effects including gram-positive and gram-negative aerobic bacteria. The drug is highly effective against Pseudomonas aeruginosa and Escherichia coli, anaerobic bacteria (Proteus mirabilis and Klebsiella pneumoniae) as well as against gram- positive bacteria (Staphylococcus spp., including S. aureus, S. epidermidis; Streptococcus spp., including Enterococcus faecalis). Conclusions. When multiresistant microbial flora is detected in patients with acute or chronic forms of pelvic inflammatory diseases an advisability of fosfomycin administration should be considered.

Physiological and Molecular Assessment of Sesbania Root Nodules Bacteria from Different Iraqi Areas for Salt Tolerance

Thirty two isolates of aerobic gram-negative bacteria associated with Sesbania sesban grown in different saline Iraqi soils was identified according to morphological and physiological characteristics, cultured on yeast-mannitol agar medium (YEMA) supplemented with different NaCl concentrations. It was indicated that 53.12% of isolates were highly tolerant to salinity, tolerated from 4.0 to 5.0 w/v NaCl. All thirty two Rhizobia isolates performed positive strong reaction to Catalase enzyme except for three were negative to this enzyme. Concerning exo-polysaccharide (EPS) production the isolates displayed a significant difference between them and that salt tolerance isolates gave a high amount of EPS production in compare to the sensitive ones. As for antibiotic sensitivity of Sesbania isolates data revealed that 83% of isolates were highly resistant to Ampicilin at 50 µgml-1, the cluster analysis based on all phenotypical and physiological characters divided the isolates into two major groups, the first group included one isolate Ses10, which was salt moderate tolerant. The second group included the rest of isolates which splits into two subgroups with 6% similarity, the first subgroup comprised all sensitive isolates plus one salt moderate tolerant isolate (Ses9).The assumption that district environmental conditions plays a vital role on field survival of bacteria, give rise to the use of PCR methods to identify Rhizobia. In this study the genetic divergence of fast nodulating bacteria connected with Sesbania in Iraq was examined. A selection of Rhizobia isolates were characterized by RAPD –PCR. Amplification of genomic DNA using three random primers (RAPD) gave various bands, the results revealed that most efficient and highest discrimintory power primer was 35.4% and 37% respectively for primer OPA-10. The cluster analysis based on RAPD-PCR amplification results showed two divergent groups with 15% similarity, the first group included two salt sensitive Ses17 and Ses28, and the second major group comprised all salt moderate and tolerant isolates.

Antimicrobial Effects of Silver(I) and Bismuth(III) Complexes with Secnidazole‑Derived Schiff Base Ligands: the Role of the Nitro Group Reduction

[Ag(HL)NO3] complexes (1-4) were obtained with (E)-N’-(1-(2-methyl-5-nitro-1H-imidazol-1-yl)propan-2-ylidene)acetohydrazide (HL1); (E)-N’-(1-(2-methyl-5-nitro-1H-imidazol-1-yl)propan-2-ylidene)benzohydrazide (HL2); (E)-2-(1-(2-methyl-5-nitro-1H-imidazol-1-yl)propan-2-ylidene)hydrazinecarbothioamide (HL3) and (E)-N-methyl-2-(1-(2-methyl-5-nitro-1H-imidazol-1-yl)propan-2-ylidene)hydrazinecarbothioamide (HL4) secnidazole-derived Schiff bases. In addition, complexes [Bi(HL3)Cl3] (5) and [Bi(HL4)Cl3] (6) were also prepared. The silver(I) complexes (1-4) showed antifungal activity against Candida fungal strains while the uncomplexed ligands and the bismuth(III) complexes (5-6) were inactive, suggesting that the antifungal effects are probably due to the presence of silver. Although the Schiff base ligands and complexes (1-6) revealed to be inactive against Gram-positive and Gram-negative aerobic bacteria, all compounds exhibited potent antimicrobial effects against several anaerobic bacterial strains, indicating that their mode of action probably involves anaerobic bio reduction of the nitro group, with formation of metabolites which are toxic to the microorganisms. Electrochemistry studies showed that bio reduction of the nitro group is favored in complexes (1-6) in comparison to the free ligands, which might, at least in part, explain their increased antimicrobial effects.

Sarecycline hydrochloride for the treatment of acne vulgaris.

Sarecycline hydrochloride (Seysara) is a novel, narrow-spectrum tetracycline derivative approved by the U.S. Food and Drug Administration (FDA) in October 2018 for the treatment of inflammatory non-nodular moderate to severe acne vulgaris. It was initially developed by Paratek Pharmaceuticals, Inc. (U.S.) and Allergan plc (U.S.), which later was acquired by Almirall S.A. (Barcelona, Spain). Almirall S.A. obtained U.S. FDA approval of oral sarecycline tablets under the trade name Seysara. Sarecycline exhibits antibacterial activity against important skin/soft tissue pathogens with targeted activity against Cutibacterium acnes--an anaerobic Gram-positive bacterium linked with acne lesions--and also exerts anti-inflammatory effects as do other tetracyclines used in the treatment of acne vulgaris. Interestingly, unlike the broad-spectrum tetracyclines, sarecycline is less potent against aerobic Gram-negative bacilli and anaerobic bacteria associated with endogenous intestinal microbial flora. This provides it with a more specific antibacterial spectra with lower chances of adverse off-target antibacterial effects, thus making it a promising choice of treatment over others in its class. It has also demonstrated low propensity to resistance as compared with other tetracyclines and is also active against tetracycline-resistant Staphylococcus aureus as well as erythromycin- and clindamycin-resistant C. acnes strains. Sarecycline has successfully undergone numerous phase I, phase II and three phase III studies establishing it as a well-tolerated once-daily oral drug available as a tablet for the treatment of patients 9 years of age or above.