Growth Of Gram-negative Bacilli Research Articles

Risk factors associated with preterm labor, with special emphasis on preterm premature rupture of membranes and severe preterm labor.

Preterm labor (PTL) can lead to preterm birth, which can cause neonatal mortality and morbidity. Preterm premature rupture of membranes (PPROM) and severe PTL (SPTL) are serious PTL subtypes. Hereby, we aimed to investigate risk factors associated with PPROM and SPTL, among Egyptian women. In this case-control study, 117 women were enrolled without any known medical risk for PTL. The control group (n = 45) had term labor (≥37 gestational weeks), while the case group (n = 72) had PTL (<37 gestational weeks). The PTL group was subdivided into those with PPROM (n = 18) and those with intact membranes (n = 54). Fifty-two PTL women, with accurate gestational age, were subdivided into SPTL (n = 31, ≤34 gestational weeks) and mild preterm labor (MPTL; n = 21, 35-36 gestational weeks). All groups were examined for different demographic characteristics, obstetrical history, clinical signs, and vaginal and urinary tract infections. Nominal logistic regression was applied to investigate significant variables associated with PPROM and intact membranes PTL, while ordinal logistic regression was used to estimate significant variables associated with SPTL and MPTL. The final multivariate nominal model identified abortion history, heavy vaginal bleeding history, and elevated vaginal pH as significant predictors of PPROM. The same model identified age <20 years old, abortion history, heavy growth of vaginal organisms, and any growth of Gram-negative bacilli as the significant predictors of intact membranes PTL. The final multivariate ordinal model identified age <20 years old, abortion history, vaginal pH, and heavy growth of vaginal organisms as the significant predictors of SPTL and MPTL. Age <20 years old, abortion history, heavy vaginal bleeding, vaginal pH, and heavy growth of vaginal organisms were reported as risk factors for PPROM and SPTL. Most of these factors are related to infection; therefore, proper infection control is recommended during prenatal and antenatal care.

Bacterial contamination of catheter tips and blood culture of a veterinary hospital

Hospital infections have a great importance in unique health, especially when one takes into account that the bacteria that cause these infections can be multidrug resistant, an entry path for these microorganisms can be the peripheral venous catheter used, primarily, to maintain the patients hydration. The objective of this work was to detect bacterial contamination and identify the microorganisms involved through blood culture and culture of peripheral venous catheters used by dogs in four different sectors of a Veterinary Hospital. 21 dogs were selected, without differentiation between age or race, and 21 of them had their blood samples collected and 21 samples of catheter tip used by them. The samples were differentiated and identified by biochemical tests and separated into Gram-Negative bacilli, coagulase-negative Staphylococcus spp. and Streptococcus spp. Among the 42 samples, there was no growth in 59.52% (25) of them, in 26.19% (11) of the samples, there was growth of Gram-Negative Bacilli, 11.90% (05) were coagulase-negative Staphylococcus spp., and 2.39% (01) were Streptococcus sp. This work shows that there should be concern about contamination that may be present in catheters or hospital probes that may cause serious infections in animals or humans.

Filamentous gram-negative bacteria masquerading as actinomycetes in infectious endophthalmitis: a review of three cases

BackgroundTo report microbiological diagnostic dilemma posed by observation of unusual morphology of bacteria in the vitreous sample of a series of three cases of bacterial endophthalmitis.ResultsA non-comparative, descriptive case series is described. All three cases presented to the retina-vitreous clinic with a clinical diagnosis of acute endophthalmitis between January and April 2018. Two patients had a past history of cataract surgery, and one had antecedent trauma within 1–2 days of presentation. As per the institutional protocol, patients underwent pars plana vitrectomy with intraocular antibiotics (vancomycin and ceftazidime) and microbiological investigation of the vitreous sample. Microscopic visualization of the stained vitreous fluid revealed the presence of filamentous organisms suggestive of Actinomycetales. However, the culture showed growth of gram-negative bacilli (Pseudomonas aeruginosa, Klebsiella oxytoca, Morganella morganii) which were identified by ViTEK 2 compact system and biochemical tests. Though a combination antibiotic treatment of vancomycin and ceftazidime was given in all cases in view of the short history, the antibiotic susceptibility testing showed multi-drug resistance pattern in two out of three cases leading to unfavorable clinical outcome.ConclusionsGram-negative bacilli can develop abnormal morphology due to stress or sub-inhibitory antibiotic exposure, and it is important for ocular microbiologists and pathologists to be aware of this phenomenon to avoid misinterpretation that may lead to inappropriate treatment.

Risk of infection transmission in curvilinear array echoendoscopes: results of a prospective reprocessing and culture registry

The complex design of the elevator mechanism in duodenoscopes has been recognized as a challenge for disinfection and recently implicated as a potential source of persistent bacterial contamination. Curvilinear array (CLA) echoendoscopes also have an elevator mechanism; however, there are no recommendations or data regarding the risk of persistent bacterial contamination of echoendoscopes. Here we hoped to determine the yield of microbial growth with routine bacterial surveillance cultures of reprocessed CLA echoendoscopes. Beginning in February 2015 to February 2016, CLA echoendoscopes at a single tertiary care center underwent prospective bacterial surveillance cultures after reprocessing. Any growth of gram-negative bacilli was considered to be critical. Echoendoscopes with a positive result underwent quarantine followed by repeat disinfection and culture. During the study period, 540 cultures were obtained; 521 (96.5%) were primary cultures obtained from 18 CLA echoendoscopes. Twenty-two primary cultures (4.2%) were positive for gram-negative bacilli after high-level disinfection reprocessing. Eleven different bacteria were isolated: Klebsiella pneumoniae, Citrobacter freundii, Escherichia coli, Pseudomonas aeruginosa, Klebsiella oxytoca, Sphingomonas paucimobilis, Acinetobacter baumanii, Enterobacter cloacae, Hafnia alvei, Pseudomonas putida, and Stenotrophomonas maltophilia. Antibiotic sensitivity data on 19 of 24 bacteria (79.2%) isolated from positive primary cultures revealed no documented cases of carbapenem-resistant enterobacteriaceae, cephalosporin-resistant-Klebsiella, or multidrug-resistant Acinetobacter. There have been no documented cases of patient-to-patient transmission. After following standard high-level disinfection and reprocessing, CLA echoendoscopes can remain culture positive for high-concern organisms. Recommendations regarding infection risk should take into consideration elevator-containing echoendoscopes in addition to duodenoscopes to ensure patient safety and endoscope reprocessing efficacy.

Port type is a possible risk factor for implantable venous access port-related bloodstream infections and no sign of local infection predicts the growth of gram-negative bacilli.

BackgroundImplantable venous access port (IVAP)-related blood stream infections (BSIs) are one of the most common complications of implantable venous ports. The risk factors and pathogens for IVAP-related BSIs are still controversial.MethodsWe retrospectively reviewed all patients who received IVAPs at a Hospital in Taiwan from January 1, 2011 to June 31, 2014. Two types of venous port, BardPort® 6.6 fr (Bard port) and Autosuture Chemosite® 7.5 fr (TYCO port) were used. All patients with clinically proven venous port-related BSIs were enrolled.ResultsA total of 552 patients were enrolled. There were 34 episodes of IVAP-related BSIs during the study period for a total incidence of 0.177 events/1000 catheter days. Port type (TYCO vs. Bard, HR = 7.105 (95 % confidence interval (CI), 1.688–29.904), p = 0.0075), age > 65 years (HR = 2.320 (95 % CI, 1.179–4.564), p = 0.0148), and lung cancer (HR = 5.807 (95 % CI, 2.946–11.447), p < 0.001) were risk factors for port infections. We also found that no local sign of infection was significantly associated with the growth of gram-negative bacilli (p = 0.031).ConclusionsTYCO venous ports, age > 65 years, and lung cancer were all significant risk factors for IVAP-related BSIs, and no sign of infection was significantly associated with the growth of gram-negative bacilli.

Melioidosis as a cause of femoral osteomyelitis and multifocal intramuscular abscess around the hip joint in a farmer: a case report

Melioidosis is a potentially fatal infectious disease caused by the soil transmitted saprophyte Burkholderia pseudomallei. Though Sri Lanka being considered a non endemic country, with the increasing number of cases reported recently there is mounting evidence that the disease is emerging here. Osteomyelitis caused by Burkholderia psuedomallei infection is uncommon and only few cases were found in the literature. We report a case of proximal femoral osteomyelitis and multifocal intramuscular abscess around the hip joint caused by Burkholderia psuedomallei in a Sri Lankan farmer. A 57 year old Sinhalese male farmer was admitted with intermittent high grade fever and left hip pain for 3 weeks. He was found to have diabetes. Ultrasound scan of the left hip joint revealed a joint effusion of 1 cm. Whole body anterior and posterior delayed images of a Tc-99m MDP bone scan demonstrated intense tracer uptake in the left proximal femur and the CT pelvis revealed a left side multi focal intramuscular abscess around the hip joint and proximal femur osteomyelitis. The CT guided aspiration of the intramuscular abscess fluid yielded a growth of gram negative bacilli, identified as pseudomonas species. Blood for antibodies for Burkholderia psuedomallei revealed a positive result at a titre of 1:320. He was diagnosed as having probable melioidosis with multifocal intramuscular abscess around the left hip joint and left proximal femoral osteomyelitis. He responded to intravenous meropenem 1 g twice a day and was continued for 4 weeks and was discharged on maintenance regime of oral cotrimoxazole 1920 mg twice a day and oral doxycycline 100 mg twice a day for 20 weeks. Our patient remained asymptomatic after 6 months of follow up and a subsequent ultrasound and CT images showed full resolution of the osteomyelitis and failed to demonstrate any abscess formation. This case alerts clinicians regarding the unusual aetiology of osteomyelitis caused by Burkholderia psuedomallei especially in patients with diabetes and those who have prolonged contact with soil. In such situations early institution of appropriate antibiotics will be life saving and a prolonged maintenance therapy with oral antibiotics is essential to prevent recrudescence of the infection. DOI: http://dx.doi.org/10.4038/sljid.v3i1.4655

Medical Management of Post-Operative Abdominal Infection: A Case of Well Management and Appropriate Medications

A 55 years old man was presented with abdominal pain and even distension. Patient was admitted from clinic for persistent pus discharge from wound suture. Present case is established case of hypertension, colon cancer, familial adenomatous polyposis and liver metastases changes stage four (post panproctocolectomy with ileoanal anastomosis with ileal pouch and disfunctioning ileastases). Operation procedure is done with multiple liver nodule, tumor sigmoid and descending colon while small bowel and stomach was normal. After 2 months of surgical procedure, patient’s pus discharge was confirmed with presence of mixed growth of gram negative bacilli and gram positive cocci. To improve the prognosis of patient with intra abdominal infection, monitoring of wounds, examination of tissue or pus discharge and proper selection of antibiotic treatment must be practicized. The bacteria inoculums must be controlled and diminished in the most effective manner depending on the patient condition. Mechanistic approach of surgeon and professional attitude may retard the accelerated prognosis of post operative intra-abdominal infections of the cancer patient.

A CROSS-SECTIONAL STUDY TO DETERMINE THE PROFILE AND ANTIBIOTIC RESISTANCE PATTERN OF GRAM NEGATIVE BACILLI ISOLATED FROM INTENSIVE CARE UNIT PATIENTS IN A TERTIARY CARE HOSPITAL IN AHMEDNAGAR, MAHARASHTRA

The present study was conducted to track down commonest gram negative bacilli along with their pattern of resistance to antibiotics from various clinical specimens, from patients admitted to intensive care unit. A total of 182 clinical specimens were analyzed using standard techniques. Out of 182 specimens 105 were culture positive, whereas the remaining 77 were culture negative. From 105 culture positive specimens 65 (61.90%) showed growth of gram negative bacilli, remaining 40 (38.09%) with growth of gram positive organisms. In this study E .coli was found to be the predominant isolate with 44.61% rate of isolation, followed by Klebsiella pneumoniae 15.38%, rate of isolation of Proteus mirabilis, Citrobacter fruendii each accounting for 9.23%. Pseudomonas aeruginosa 7.69%, Proteus vulgaris 3.07%, Acinetobacter species and Salmonella typhi accounted for 1.53 % each. To conclude, aerobic gram negative bacilli were predominant clinical isolates from patients admitted to intensive care unit. Amikacin and gentamicin were found to be effective antibiotics against gram negative bacilli in this particular setting

Bacteriemia por Salmonella enteritidis como debut clínico de síndrome de inmunodeficiencia adquirida

The case is presented of a 38 year-old patient who was admitted in the Emergency Department due to a severe acute respiratory failure and who was transferred to the Critical Care Unit with a suspected initial diagnosis of community acquired pneumonia caused by an atypical microorganism, which was complicated with an acute respiratory distress syndrome. This was able to be treated with non-invasive mechanical ventilation. At 48hours after admission, the growth of Gram negative bacilli in the blood culture was reported, which was subsequently identified as Salmonella enteritidis. This information, along with the lymphopenia suffered by the patient, suggested an immunodepressed state, thus serological tests were performed which showed positive for HIV. Antibiotic treatment was started based on the microbiological findings, with a favourable clinical outcome for the patient.

A pilot study evaluating the safety and microbiologic efficacy of an economically viable antimicrobial lozenge in patients with head and neck cancer receiving radiation therapy

Mucositis occurs in almost all radiotherapy-treated head and neck cancer patients, in approximately 75% of patients receiving hematopoietic marrow transplantation, and in approximately 40% of all patients who receive chemotherapy. Mucositis is painful, may affect all oral functions, and is a dose- and rate-limiting toxicity of therapy for cancer. Radiation-associated mucositis (onset, intensity, and duration) has been shown in recent clinical trials to be modified by the use of antibacterial/antifungal lozenges. The aim of this collaborative two-center phase II study was to assess the toxicity and microbiologic efficacy of an economically viable antimicrobial lozenge in the management of patients receiving radiation therapy for head and neck cancer. Seventeen patients scheduled to receive radical or postoperative radiotherapy were provided with bacitracin, clotrimazole, and gentamicin (BCoG) lozenges (one lozenge dissolved in the mouth qid from day 1 of radiotherapy until completion). Ease of use and palatability of the lozenges, patients' symptoms (swallowing and pain), and quantitative and qualitative microbiologic evaluation of an oral rinse collection was conducted at least once weekly during radiation therapy. No significant side effects were reported from the use of the lozenges. The lozenges were well tolerated at the beginning of treatment by all patients, with some minor difficulty associated with oral discomfort toward the end of the treatment. Microbiologic evaluation showed consistent elimination of yeast organisms in all patients. In four patients there was no growth of gram-negative bacilli on culture, whereas in two patients, fluctuating counts were seen, and one patient had increased counts. The remaining patients had significant reduction in the gram-negative bacilli counts. This study demonstrated that the BCoG lozenge is tolerable and microbiologically efficacious, achieving elimination of Candida in all patients and reduction in gram-negative flora in most patients. A phase III study is underway to evaluate the clinical efficacy of this lozenge.

The Diagnostic Value of Gram Stain for Initial Identification of the Etiologic Agent of Peritonitis in Capd Patients

To evaluate the effectiveness of the Gram stain in the initial diagnosis of the etiologic agent of peritonitis in continuous ambulatory peritoneal dialysis (CAPD). Retrospective study analyzing the sensitivity (S), specificity (SS), positive predictive value (+PV), and negative predictive value (-PV) of the Gram stain relating to the results of cultures in 149 episodes of peritonitis in CAPD. The data were analyzed in two studies. In the first, only the cases with detection of a single agent by Gram stain were taken (Study 1). In the second, only the cases with two agents in Gram stain were evaluated (Study 2). Dialysis Unit and Laboratory of Microbiology of a tertiary medical center. Sixty-three patients on regular CAPD who presented one or more episodes of peritonitis from May 1992 to May 1995. The positivity of Gram stain was 93.2% and the sensitivity was 95.7%. The values of S, SS, +PV, and -PV were respectively: 94.9%, 53.5%, 68.3%, and 90.9% for gram-positive cocci and 83.3%, 98.8%, 95.2%, and 95.6% for gram-negative bacilli. The association of gram-positive cocci plus gram-negative bacilli were predictive of growth of both in 6.8%, growth of gram-positive cocci in 13.7%, and growth of gram-negative bacilli in 72.5%. The Gram stain is a method of great value in the initial diagnosis of the etiologic agent of peritonitis in CAPD, especially for gram-negative bacilli.

Routine endotracheal cultures for the prediction of sepsis in ventilated babies.

Serial cultures of endotracheal tube aspirates were carried out in 94 neonates who were intubated and had been ventilated for longer than one week. A similar change in bacterial colonisation with duration of ventilation was seen in infants who subsequently developed sepsis and those who did not. In both groups, 177 aspirates (more than 90%) obtained during the first week of ventilation were sterile. Thereafter, colonisation with mixed Gram positive flora emerged followed by growth of Gram negative bacilli. For the infants who developed sepsis, the correlation between pathogens isolated from blood during the episodes of sepsis and those from previous endotracheal tube isolates was poor; in only five of the 26 cases of sepsis (19%) was the same single strain of organism isolated from culture of the blood and of the endotracheal tube aspirate. Other markers of infection such as endotracheal tube aspirate white blood cell counts and changes in bacterial flora were not useful in predicting systemic infection. Routine surveillance cultures of endotracheal tube aspirates in ventilated infants are not helpful in predicting the pathogens that are isolated from the blood during episodes of sepsis.

Microbial Contamination of Continuous Drip Feedings

We evaluated the extent and effects of bacterial contamination of an open continuous enteral feeding system. Eighty-two quantitative enteral feeding cultures and clinical data were obtained during 8 days of observation on each of 33 patients. Cultures of appropriate sites were obtained on febrile patients and compared to the enteral feeding culture. Gram negative bacilli (GNB) in the enteral feeding correlated with abdominal distension in the patients (10 of 12 patients with GNB compared to 5 of 21 without GNB; p less than 0.01). Nine of the 10 patients with GNB and distension were receiving systemic antimicrobics to which the organism was resistant. Contamination of feeding with Serratia marcescens correlated with cultures for the same organism in patients' other body sites (p less than 0.01). The feeding contaminant may have been the source of sepsis in one patient who expired from septic shock. No relationship was demonstrated between contamination and liquid stools or fever. Undiluted, canned feedings were significantly less contaminated at 24 hr (15%) than those requiring mixing of powder (94%) (p less than 0.0001). The canned feedings grew primarily enteric organisms, whereas the powder feedings grew flora typically resident on the skin. Mixing or diluting feedings appears to represent an increased risk of contamination. Growth of GNB may produce adverse effects. Further investigation into methods to limit contamination and growth is warranted.

Microbial contamination of continuous drip feedings

We evaluated the extent and effects of bacterial contamination of an open continuous enteral feeding system. Eighty-two quantitative enteral feeding cultures and clinical data were obtained during 8 days of observation on each of 33 patients. Cultures of appropriate sites were obtained on febrile patients and compared to the enteral feeding culture. Gram negative bacilli (GNB) in the enteral feeding correlated with abdominal distension in the patients (10 of 12 patients with GNB compared to 5 of 21 without GNB; p less than 0.01). Nine of the 10 patients with GNB and distension were receiving systemic antimicrobics to which the organism was resistant. Contamination of feeding with Serratia marcescens correlated with cultures for the same organism in patients' other body sites (p less than 0.01). The feeding contaminant may have been the source of sepsis in one patient who expired from septic shock. No relationship was demonstrated between contamination and liquid stools or fever. Undiluted, canned feedings were significantly less contaminated at 24 hr (15%) than those requiring mixing of powder (94%) (p less than 0.0001). The canned feedings grew primarily enteric organisms, whereas the powder feedings grew flora typically resident on the skin. Mixing or diluting feedings appears to represent an increased risk of contamination. Growth of GNB may produce adverse effects. Further investigation into methods to limit contamination and growth is warranted.

The bactericidal action of beta progesterone

In a study of bacteriologically proved and clinically suspected cases of acute gonorrhea it was shown by Koch, 1947, that negative cultures are associated with the luteal phase of the menstrual cycle, when progesterone activity and acidity of the cervical mucus are at their height. Swartz, Shohl, and Davis, 1920, proved the acid-death point of the gonococcus, in vitro, to be pH 6.6. On the basis of the above data experiments were made to determine whether or not pure crystalline beta progesterone would have any effect upon the viability of the gonococcus in vitro, if incorporated in a medium adjusted to a favorable pH for growth of the organism, and in a slightly acid medium. Other members of the Neisseria and representatives of the gram-positive and gram-negative organisms were also included in this study.In 1943, Faulkner made an extensive in vitro study of the effect of estrogens upon a group of organisms and concluded that diethylstilbestrol was bactericidal and in a lesser concentration bacteriostatic to the gram-positive cocci, Corynebacterium diphtheriae and Neisseria catarrhalis. No inhibitory action was obtained upon the growth of gram-negative bacilli. The minimal lethal concentration varied between 1:5,000 and 1:50,000. Estrone, estradiol, and diethyloxytriphenolbromoethylene did not have any bactericidal action. Sabatelli, 1946, reported that high doses of “folliculin” (16 and 32 I.U. per 10 ml. of ascitic agar) have an inhibitory action upon the growth of the gonococcus in vitro, but no mention was made of the specific estrogenic hormones used. Koch, 1947, was unable to obtain any inhibition of growth of the gonococcus using concentrations of 1:5,000 and 1:10,000 of pure crystalline alpha estradiol incorporated in pancreatic digest broth pH 7.4.

An Example of Bacterial Synergism on Endo Medium.

Bacterial Synergism has usually been studied in fluid medium. I wish to report here an example of the association of B. welchii and B. faecadis alkaligenes on an Endo plate with a resulting change of the type of colony formed by the latter. A swab taken from the drainage wound of an acutely infected shoulder, was planted in hormone-dextrose-broth and on blood agar. The broth showed a growth of gram negative bacilli and gram positive cocci in chains. The blood agar showed haemolytic colonies of streptococci and colonies of the coliform type. The broth culture was spread on an Endo plate and after 24 hours incubation this plate showed numerous colonies with red centers and narrow, colorless peripheries. In such isolations only colorless colonies are usually picked for further study, but because of the colorless periphery of these colonies, one was transferred to hormone broth. A smear from a 24 hour growth of this culture showed nothing but gram negative bacilli. Generous portions of the broth culture were ...